| Author | Message | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 20 Registered: 11-2008 Posted From: 70.49.114.69  Rating: N/A |
Sorry guys but – as some of you know – I’m probably the newest ‘newbie’ in this consortium of bus wackjobs (I include myself in that fine group, so please don’t be too offended). I’d really love some more thoughts related to those posts. … to help you get better oriented, the thread was started by Dan Newport (Divemaster) on August 25, and he got lots of great input. Particularly relevant to my question, though, was the feedback from George MC6 and from Jack Conrad. Hard starting is not my problem. Okay, I take that back. My old DD 8V-71 is a b**** to start too, but I already know the reason for that: -20 F. and straight 40W oil. But I’d love to hear more about those air cut-off systems, particularly “…I don't know how your start/low oil pressure override is done, but it doesn't matter, its there, or the engine will continue to run with the Low Oil Pressure alarm on. When you try to start with no air pressure, the point is moot.” (This quote from George). Well, my engine DOES continue to run with the low oil pressure alarm on. Or maybe it's the High Temp alarm? I can’t tell if it’s ‘Low Oil’ or ‘High Temp’ because BOTH warning lights flash with the alarm. BUT, when that alarm blares (which scares me sh**less) the temp is under 190 degrees and the oil pressure is in the normal range. At least I ASSUME it's normal: somewhere between 30-60 lbs., depending on RPM. My rear temp gauge – recently installed – corresponds to my dash temp gauge (within a couple degrees, both at 187 or thereabouts. I touch the block, the rads, the pipes – even the exhaust – and nothing makes me draw my hand back. Nothing smells hot either, and nothing looks hot - no steam, no smoke and no melting insulation. The engine isn't room temperature, but neither is it a fire hazard. Heck, I want to hug the poor old thing, tell her she had a bad dream and tuck her back into bed. Still, whenever this happens (the alarm), I frantically pull off the side of the road, fearing I’ve destroyed my big cast-iron freedom machine. THE SYSTEM: The oil seldom drops even a centimeter, the engine smokes not even a puff, and even after a few hundred miles, I can wipe the engine (and compartment) clean with a couple squirts of WD-40 and some Scott paper towels. The coolant, even after a full year of intermittent starting and short runs (VERY short by Bus Nut standards) has dropped by less than one litre (at least according to the sight glass, which seems to be accurate). To correct one misstatement (above): I DO get some light white smoke when cranking (when it’s cold outside) and (when it’s SUPER-cold) some unburned diesel (but not much) from the exhaust cross-over. This occurs just during warm up, and ceases at around 100 degrees coolant temperature. To spare you some diagnostic questions: The engine is old (obviously) but a complete factory rebuild was done less than 2500 miles ago (see my post to Paul a couple days ago). However, the old gal sat for awhile after that (2 years) and had virtually no TLC. When I got her, she cranked up with just a couple tired old car batteries… I drove her across some of the crappiest roads you’ve ever seen (from North Bay, Ontario to Shawinigan, Quebec), re-fitted her enough to pass Quebec’s notorious 130 point inspection and citizen torment program and – three blocks’ out of the Franco–Nazi harassment center (garage) – she sh** herself. UnKUh … UnKuh… BOOM! She stopped dead cold, wheezing billows of black smoke but wouldn’t shut down. Luckily, somehow, the shutoff finally kicked in and she fell mercifully unconscious. Twelve days and $2300 later – after being milked by some local j***off truck mechanics who purposely scared me to death – I found a real bus guy who purged the air from my fuel line, fixed a bad connection, and had me on my way. Total cost: $60.00 [A note: I was about to offer a first fledgling contribution to this wonderful forum. But then I realized it was totally off subject, even though peripherally related. But since I wrote it, I'll begin a new thread) inapproprite is direceted to the next newbie. (You vets already know it, but it's so basic you take it for granted) No matter how long it takes, wait for a 'bus guy.' Do NOT assume a truck guy knows buses. A truck guy often doesn't even know trucks. Many of them are what I call 'hammer mechanics'- they are mostly rough and insensitive louts, lacking the sensitivity and savoir faire to relate to your fine princess. Beware of hammer mechanics - they will cripple your beauty. postive [I still have that guy’s info, for anyone nutty enough to head that way (having said that, I probably will too... there’s a great country music festival up there in late summer)] Anyway, Nomad’s Land (that’s my baby’s name) growled her way down to the Eastern Townships (Quebec)- a loping 76 (mph) @ 1950 and only two gear changes (into third). Sweet! Then into Vermont and through the mountains. Many gear changes there (not so sweet). Then back north several times to Sherbrooke, QC and Montreal. And except for my clumsy shifting, she floated like a big fat Cadillac. I kicked her a couple times - couldn't resist - and don't those old DDs just SNARL when they're angry! But just lately, this alarm thing has begun. I thought it might have been the Cadillac radiator shutters… they didn’t seem to be opening when the bus warmed up. So I took those apart, cleaned and oiled the moving parts and refreshed the air lines (everything was plugged with sludge and road grime). Now they seem to work properly??? At least they open when the bus is shut down, and they automatically close during warm up. But I can’t get her past 160 or so even on fast idle, so who knows if they’ll open at operating temp ? Also – from an abundance of caution – I followed FF’s advice and flushed the cooling system and refilled with distilled water and additives – similar formula as ‘Power Cool 3000.’ [Sorry, Fred, couldn’t find your suggested additive and couldn't be as meticulous as you might be… But I can’t drive this thing in the snow, especially in the mountains. But since I just installed new radiators and the coolant was fresh, I figured cutting a few corners wouldn’t hurt.] So here are my concern: These shutters aren’t even SUPPOSED to open until a temp of 190 degrees. So what do I do with that? My alarm comes on at 187 – give or take – but the shutters aren’t supposed to open until 190….? You might be asking, how does Nellie know that? Well… I read it right here on this BBS and, until somebody says otherwise, I take it as absolute gospel – you see, guys, you’re the only panel of experts I have. And certainly the only onesI trust. Thanks again. Nellie Wilson PS to George and Ian – many thanks for that schematic. I’ve printed yours and the one from Don, and am meeting with a heavy equipment guy tomorrow. Wanna guess where he’s from? ………. Okay, times up. He’s from Leadville, Colorado! Ever been up there? I have and I gotta say, you can’t trust a guy from Leadville, Colorado, you can’t trust anybody. (‘course I could be wrong, too) And, Don, no intention to slight you at all … just recall having already thanked you? But since I’m too tired to go look, thanks again! I’ll let everyone know how this works out. I’ll even take notes. | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 21 Registered: 11-2008 Posted From: 70.49.114.69 Rating: N/A |
To All: I apologize for the last totally incoherent post. It was meant only as a draft, but I hit the wrong key and posted the d*** thing. Sorry again, and please ignore. From here on, I shall compose only in MS Word and 'Copy' and 'Paste' when I am satisfied as to content. Most chagrined, Nellie Wilson | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 22 Registered: 11-2008 Posted From: 70.49.114.174 Rating: N/A |
All right, let’s try this again. Probably still ain't great, but it's better. Whew! Sorry guys but – as some of you know – I’m probably the newest ‘newbie’ in this consortium of bus wackjobs (I include myself in that fine group, so please don’t be too offended). I’d really love some more thoughts related to those posts. To help you get better oriented, the thread was started by Dan Newport (Divemaster) on August 25, and he got lots of great input. Particularly relevant to my question, though, was the feedback from George MC6 and from Jack Conrad. Hard starting is not my problem. Okay, I take that back. My old DD 8V-71 is a b**** to start too, but I already know the reason for that: -20 F. and straight 40W oil. But I’d love to hear more about those air cut-off systems, particularly “…I don't know how your start/low oil pressure override is done, but it doesn't matter, its there, or the engine will continue to run with the Low Oil Pressure alarm on. When you try to start with no air pressure, the point is moot.” (This quote from George). Well, my engine DOES continue to run with the low oil pressure alarm on. Or maybe it's the High Temp alarm? I can’t tell if it’s ‘Low Oil’ or ‘High Temp’ because BOTH warning lights flash with the alarm. BUT, when that alarm blares (which scares me sh**less) the temp is under 190 degrees and the oil pressure is in the normal range. At least I ASSUME it's normal: somewhere between 30-60 lbs., depending on RPM. My rear temp gauge – recently installed – corresponds to my dash temp gauge (within a couple degrees, both at 187 or thereabouts. I touch the block, the rads, the pipes – even the exhaust – and nothing makes me draw my hand back. Nothing smells hot either, and nothing looks hot - no steam, no smoke and no melting insulation. The engine isn't room temperature, but neither is it a fire hazard. Heck, I want to hug the poor old thing, tell her she had a bad dream and tuck her back into bed. Still, whenever this happens (the alarm), I frantically pull off the side of the road, fearing I’ve destroyed my big cast-iron freedom machine. THE SYSTEM: The oil seldom drops even a centimeter, the engine smokes not even a puff, and even after a few hundred miles, I can wipe the engine (and compartment) clean with a couple squirts of WD-40 and some Scott paper towels. The coolant, even after a full year of intermittent starting and short runs (VERY short by Bus Nut standards) has dropped by less than one liter (at least according to the sight glass, which seems to be accurate). To correct one misstatement (above): I DO get some light white smoke when cranking (when it’s cold outside) and (when it’s SUPER-cold) some unburned diesel (but not much) from the exhaust cross-over. This occurs just during warm up, and ceases at around 100 degrees coolant temperature. To spare you some diagnostic questions: The engine is old (obviously) but a complete factory rebuild was done less than 2500 miles ago (see my post to Paul a couple days ago). However, the old gal sat for awhile after that (2 years) and had virtually no TLC. When I got her, she cranked up with just a couple tired old car batteries… I drove her across some of the crappiest roads you’ve ever seen (from North Bay, Ontario to Shawinigan, Quebec), re-fitted her enough to pass Quebec’s notorious 130 point Inspection and Citizen Torment Program and – three blocks’ out of the Franco–Nazi Harassment Center (garage) – she sh** herself. UnKUh … UnKuh… BOOM! She stopped dead cold, wheezing billows of black smoke but wouldn’t shut down. Luckily, somehow, the shutoff finally kicked in and she fell mercifully unconscious. Twelve days and $2300 later – after being milked by some local j***off truck mechanics who purposely scared me to death – I found a real bus guy who purged the air from my fuel line, fixed a bad connection, and had me on my way. Total cost: $60.00 [I still have that guy’s info, for anyone nutty enough to head that way (But having said that, I probably will too... there’s a great country music festival up there in late summer)] Anyway, Nomad’s Land (that’s my baby’s name) growled her way down to the Eastern Townships (Quebec) - loping along at a true 76 (mph) @ 1950 and only two gear changes (into third). Sweet! Then into Vermont and through the mountains. Many gear changes there (not so sweet). Then back north several times to Sherbrooke, QC and Montreal. Except for my clumsy shifting, she floated like a big fat Cadillac. I kicked her a couple times - couldn't resist - and don't those old DDs just SNARL when they're angry! But just lately, this alarm thing has begun. I thought it might have been the Cadillac radiator shutters… they didn’t open when the bus warmed up. So I took those apart, cleaned and oiled the moving parts and refreshed the air lines (everything was plugged with sludge and road grime). Now they seem to work properly??? At least they open when the bus is shut down, and they automatically close when I start the bus and during warm up. But since I can’t get her past 160 degrees even on fast idle, who knows if they’ll open at operating temp? Also – from an abundance of caution – I followed FF’s advice and flushed the cooling system and refilled with antifreeze, distilled water and additives – similar formula as ‘Power Cool 3000.’ [Sorry, Fred, couldn’t find ‘Power Cool 3000’ and couldn't be as meticulous as you might be… I can’t drive this thing in the snow, especially in the mountains. And since I just installed new radiators and the coolant was fresh, I figured cutting a few corners wouldn’t hurt.] So here are my concerns: These shutters aren’t even SUPPOSED to open until a temp of 190 degrees. So what do I do with that? My alarm comes on at 187 – give or take – but the shutters aren’t supposed to open until 190….? You might be asking, how does Nellie know that? Well… I read it right here on this BBS and, until somebody says otherwise, I take it as absolute gospel – you see, guys, you’re the only panel of experts I have. And certainly the only ones I trust. Thanks again. Nellie Wilson PS to George and Ian – many thanks for that schematic. I’ve printed yours and the one from Don, and am meeting with a heavy equipment guy tomorrow. Wanna guess where he’s from? ………. Okay, times up. He’s from Leadville, Colorado! Ever been up there? I have and I gotta say, if you can’t trust a guy from Leadville, Colorado, you can’t trust anybody (‘course I could be wrong on that score, too). And, Don, no intention to slight you at all … just recall having already thanked you? But since I’m too tired to go look, thanks again! I’ll let everyone know how this works out. I’ll even take notes. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 553 Registered: 10-2006 Posted From: 66.82.162.14 Rating: N/A |
My old DD 8V-71 is a b**** to start too, but I already know the reason for that: -20 F. and straight 40W oil. That is normal, get thee to the block heater seller , and install one. Overnight with the unit plugged in and its a 1 second crank to run. FF | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 224 Registered: 10-2003 Posted From: 66.165.176.60 Rating: N/A |
Amen Fred, I took the family camping this weekend and the temps dropped to 20. Turned the heater on before I went to bed and woke up to 180 degree coolant and an engine that fired as soon as I touched the switch  (Message edited by timb on November 24, 2008) | ||
| Mark Renner (Boomer)
Registered Member Username: Boomer Post Number: 124 Registered: 11-2006 Posted From: 206.58.200.38  Rating: N/A |
Unhook the alarmstats and go on your merry way. They were meant for Greyhound drivers. One Greyhounder said "with idiot lights and alarmstats, a monkey could drive these things..." | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 159 Registered: 1-2007 Posted From: 208.81.157.90 Rating: |
Nellie, First, why you need air to shut down. There is a lever on the governor that is pushed by an air cylinder to shut down the engine. No air, no shut down. If you start the engine with zero air and try to turn it off immediately, nothing happens until there is enough air pressure to operate the shut down cylinder. Same cylinder is used by the over temp and low oil pressure systems to kill engine. Your alarm problem. First you need to determine if there is a real problem trigging the alarm or is there a fault in the alarm system. You mentioned that your rear temp gauge agrees with the front, thats good. Does your rear oil pressure gauge agree with the front? When the alarm goes off and you pull over what does the alarm do? Does it continue or stop? Or do you shut down immediately? As far as I know the alarm and shut down systems of non DDEC engnes are composed of switches that close on alarm and/or shut down, meaning when the alarm/shutdown point is reached the system is triggered by closing a switch to ground located in the sender. If this is happening a lot and you are sure oil pressure and water temp are OK, you can disconnect the alarm senders one at a time and see if the problem goes away. Alarm senders are relatively cheap compared to trying to isolate the problem. More so if you are paying someone to trouble shoot it. Sometimes the shot gun approach is cheaper and easier than tracing down an intermittent problem. On my bus, a GM, they are easy to get to for trouble shooting. On yours they may not be. If it were me, I would change the low oil pressure alarm sender and the high temp alarm sender as the first step to find the problem. While you are at it a close look at the wiring harness. If a wire to one of these senders is shorting to ground the alarm will trigger. Good luck Don 4107 (Message edited by doninwa on November 24, 2008) | ||
| Tony LEE (T_lee)
Registered Member Username: T_lee Post Number: 40 Registered: 11-2007 Posted From: 60.229.41.225 Rating: N/A |
I think the low coolant level also trips the protection circuit.Does on my MC8 | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 625 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Nellie, Don has the shutdown system to a T, thus my vote! Unless you're numb, you can't touch an exhaust manifold on a running engine! (Humour) {Spelled Canadian} The temperature and oil pressure SENDING UNITS, and the SHUTDOWN SWITCHES, are both seperate entities, their only commonalities are their mechanical connections to the water and oil lines. The both operate by grounding their wire, so a bare spot in the insulation somewhere in the engine room will give you a false alarm. As wired from the factory, the hot eng or low oil alarm will stop the engine, only if there is auxiliary air pressure. As the engine has no oil pressure on startup, something has to be done to get it started and running until oil pressure builds, when it has air pressure. So, there is an override circuit which keeps the Skinner valve energized as long as the start button is depressed. The Skinner valve is "normally open" which means air flows thru it with no power, air in the shutdown cylinder stops the gov. If you have a low oil or hot alarm on, with air pressure up, and the engine still runs, the shutdown wire has been removed from the circuit. Look in the back, lower curb side, and you will see an oil line off the engine, with a tee and two sending units with wires attached. One is pressure gauge, the other is alarm. With the master on, and eng dead, you should have a low oil pressure alarm. Disconnect one wire, and see if the alarm stops, if not reconnect, and remove the other. The one that stops the alarm is the one that you may need to replace. An automotive type switch will do fine, one that operates about 10 psi, no more. At the cost of a rebuild, I DO NOT advocate leaving a low oil alarm disconnected. I gotta drive now, more in a couple of days... G | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 626 Registered: 8-2006 Posted From: 76.91.197.153 Rating: N/A |
Nellie, I should have said alarm switches, not shutdown switches. Please go out and turn the master on and tell us what alarms come on. Should be two low air, low oil, and not gen. The hot eng alarm should not operate until at least 210F. The cooling system consists of thermostats which don't allow water flow until ABOUT 180F, a shuttterstat to open the shutters a little above that, a temperature sending unit to make the front gauge work, and an alarm switch to make the temp alarm work. From the factory, an alarm will stop the eng. This can be overridden by holding the start button down, to get you off the road. One wire can be removed, which allows the alarms to operate properly, and just not stop the engine. I have done that on mine. From your description of the numerous wiring problems, I would not count on the start button override, until I checked the fuel pressure switch wiring which disables the starter as soon as the engine starts. I don't think you've said it dies anyhow? G | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1397 Registered: 12-2000 Posted From: 76.68.123.23 Rating: N/A |
Auto shut down for critical alarms (hot engine, low oil) was an option from MCI. Greyhound always optioned it. Many of the rest did not. I'm thinking that Nellie's doesn't, or she would have told us all about the adventure of getting pulled over with the engine shut down. happy coaching! buswarrior | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 27 Registered: 11-2008 Posted From: 76.68.200.158 Rating: N/A |
[Hey, where'd everybody's pictures go?] Thanks to you folks, I know a lot more now than I did a few days ago. I'm still a klutz, but somewhat LESS of a klutz. Don, thanks for clearing up one thing that had bothered me for awhile ... not being able to shut the engine down right after startup. Much appreciate your explanation. As for the rear oil gauge, it seems to have been missplaced at some point... at least I've never seen it. Would one have been originally on the bus? To your question: When the alarm sounds, both the Low Oil and High Temp dash lights flash - so I don't know which problem the alarm is actually indicating. The engine does not shut down, but I shut it down pretty immediately after pulling off the road. The last couple of times, though, I left it running just long enough to check for unusual smoking and to open the engne compartment and check things out. As indicated in my original post, everything seems quite okay. Oil pressure? Having no rear gauge, I'm a little uncertain on that score. Seems to be fine on startup but - after the engine warms up and on idle - it seems a little low to me (but I don't know what's considered normal). If I click on 'fast idle' the pressure jumps right up. When the bus is under load (going down the road) the pressure varies depending on RPM and seems pretty okay. But what's okay? 30 lbs, 50 lbs? I don't really know. The bus actually did shut down one time - as described in my original post - but that was caused (apparently) from air in the fuel line. But maybe that knocked down the oil pressure which, in turn, triggered the shut down. Really impossible to be certain at this point. Okay, George, I'll do as you suggest next time I'm at the bus (it's quite a distance from where I sit). But from memory, I get only the Low Air warning (not really an alarm, but a sort of continual rattling sound). But I get the dash light warnings for several different things - as I recall, the Low Oil is one. Maybe you could clarify something: You're saying I should get actual alarms (in addition to the lights)? And did you mean I should get "two low air" or was that just a typo? And, yeah, I'm a little worried about using the starter button to overide the shutdown mechanism (if I even have a shutdown mechanism?). I like your idea of leaving the alarms intact and just disabling the shutdown (again, assuming I have one.) More coming after I can act on your advice. This thread is a little dated now (Thanksgiving and all), so if nobody checks back I'll probably start a new thread. Nellie Wilson | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 632 Registered: 8-2006 Posted From: 76.91.197.153 Rating: N/A |
Nellie, 10psi should be about the minimum oil pressure at idle, warm, and it should make about 50 at full speed. It will make more cold. As to the warning lights, mine is 8 years older, 5 feet longer, and six inches wider, even though there is only one number different in the models. Mine is equipped with two separate low air warning lights, one each for front and rear brake reservoirs, and separate lights on separate circuits for low oil pressure and hot engine. It actually has three buzzers, one does both air warnings, one does the oil and temp, and the other is the fire and lavatory alarm. Before I can speak to yours, do you have the factory schematic, and if so, could you e it to me? Some other nut may be able to do it easier, and I would welcome the help! USDOT regulations require visible and audible low air warnings, so it sounds like at best you have a couple of bulbs burned out, or wires loose or missing? The buzzers do sound like rattling. If the engine continues to run with an alarm on, as you have described, and air pressure up, either the shutdown option was not purchased, or it has been disconnected. Sitting dead cold, no air, and the master on, you should see a low oil pressure light and buzzer, and at least one low air light, and buzzers in stereo, if you listen closely. The not gen light will probably be on also, and it probably doesn't cause a buzzer. I don't want to go into why there MAY not be a not gen light with no air pressure now. Lastly, the way Ian programmed this board, it puts up a new message indicator on the left of the thread, so old threads still show when a post has been made to them. Slick! I gotta look at RJ's email now, and if we ask real nice, he might even have a 5C schematic!!! HTH, George | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 165 Registered: 1-2007 Posted From: 208.81.157.90 Rating: N/A |
Nellie, Since I have a GM I can't tell you for sure if it had a rear oil pressure gauge but I would think it should. Mine has a manifold mounted on the bulkhead that has the gauge and warning senders in it. I am sure a MCI driver will respond with where your's should be. If you don't have one it would be a very good and inexpensive investment. If you should ever have a low oil pressure indication on the front gauge due to a bad sender or bad connection a quick look at the rear gauge will tell you if there is a real problem. Also handy if you are servicing or starting the bus with the rear controls. Good luck Don4107 | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 28 Registered: 11-2008 Posted From: 70.49.112.39 Rating: N/A |
Again, George and Don, I thank you. I'm too tired now to say more (for which I'm sure you're both thankful) but I'll get back soon. After that info from George, I DO feel pretty good about that oil pressure. See ya! Nellie Wilson | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 570 Registered: 10-2006 Posted From: 66.82.162.18 Rating: N/A |
"10psi should be about the minimum oil pressure at idle, warm," In GM coaches that still use the factory Air Cond. note the low idle speed is about 400rpm , in order to get oil pressure low enough for the safety to allow the AC clutch to engage. Most folks have long ago tossed the AC , but if the idle hasn't been reset , 10psi at idle is way high, by GM design. FF | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1401 Registered: 12-2000 Posted From: 76.68.122.205 Rating: N/A |
Maybe only one low air light in that dashboard. Can't get good air in the aux where the pick-up is, without there being good air down below. Fulfills the legal requirement, and also makes sure the hired hand doesn't drive away with the air suspension down, without doing it on purpose... The road less traveled has it's moments? happy coaching! buswarrior | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 29 Registered: 11-2008 Posted From: 70.52.100.40 Rating: N/A |
So it sounds like my scrawny 10-15 psi (warm engine at low idle) isn't so bad? At least for now. But FF - and all you other guys too - what's your thinking on my plans to refresh the factory A/C and continue to use it? I mean, why does everyone demolish all this great engineering and replace it with homegrown alternatives? Not throwing stones, you understand... I just don't get the logic. But considering that most everyone "tossed the AC" (to quote Fred) I know there must be solid reasons. I'm just too much a novice to know what they are. I do suspect there are certain tradeoffs in retaining factory A/C - like those twin tranverse belts (we call 'em 'straps' up here...eh!). It seems their only function is to run the compressor. Or maybe I'm wrong about that, too... but on my bus, these belts turn no other pulleys except one (attached to a fat gray machine located at curbside). I'll (try to) upload a couple photos to show what I mean... though I'd bet you already know the belts I'm talking about? But so what... I always like your pictures, so maybe you'll like mine. I'm looking at them now, and you'll see the belts (red writing on top) that I'm talking about. From the crank pulley they angle upwards at about 30 degrees and to the right - running about parallel to that siverish tensioning piston seen in the right lower corner of the hatch (just above the bumper). So does everyone remove the AC simply to increase (driveline) horsepower and to save fuel... or is it to get the use of an additional bin? Or is the factory AC a problem to run? It just seems to me - with everyone tossing them - that parts should be plentiful and pretty darn cheap. I truly don't know... but if somebody's tossing stuff, give me a shout and I'll be right over. Okay, I'm over and out guys. I'll try to send those photos. Hey, if I can make the thing work maybe I'll send a coup;e extras, just for fun. Got some pretty neat artwork on the old hoss. Thanks a zillion, Nellie Wilson PS. Well, bummer! Couldn't upload my artsy-craftsy photos. Hope the ones of the engine show up... maybe Ian's got a restriction on size or something? PPS. Photos are formatted in Microsoft Image Composer (.mic) but saved as normal .jpg. I think any photo application should work, but you may want to increase the viewing size with your percentage 'slider.' | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 30 Registered: 11-2008 Posted From: 70.52.100.40 Rating: N/A |
Shoot. Nothing showed up. How small these photos gotta be, anyway? They're already tiny. Suggestions as how to reduce them to acceptable size? Maybe I'll try with just one... the smallest one. Bear with me... it's not nice to laugh at a lady. Nellie | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 31 Registered: 11-2008 Posted From: 70.52.100.40 Rating: N/A |
Well, screw it. Nellie Wilson | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 572 Registered: 10-2006 Posted From: 66.82.9.57 Rating: N/A |
"I just don't get the logic. But considering that most everyone "tossed the AC" (to quote Fred) I know there must be solid reasons. I'm just too much a novice to know what they are." When hound replaced an engine the night shift woud have the replacement in by midnight , the rest of the shift was taken up with the Air Cond comp alignment procedure. The shaft has to be removed every winter season in order to have better safety , should the clutch setup fail. It fails to ON , not a great prospect at 70mph. The BIGGEST problem was the system would take 3 to 5 lbs of "make up" F-12 every WEEK!! Yes its superb engineering , with flair fittings with o rings its impressive as hell, just with F- 12 unobtainable , with out a Mexico or Bahamas quick trip ,the concept of servicing it is a nightmare. There are NOW (finally) F12 replacements that are actually more 10% efficient (most are 15% to 20% WORSE), but the system would still need to be cleaned and flushed with different oil installed. We simply tossed the entire package , and found the compressor well is a perfect spot for the power cords and adapters (floor construction required). The huge heater was tossed as were the huge fans, and a 40,000 btu marine "box heater" was cut in to feed outside air in the channel (those series of holes) that fed air to the heater. Dash heat was left installed. 40,000 btu and drivers heat does heat the front of the coach to toasty on cold (15F days) , but the rear only gets to 45 or 50 , quickly brought up to spec at a campground with the furnace. A second box heater would keep the rear toasty if folks are showering as you drive. The power setup supplied (160A) to the blowers is left in place and could handle the house battery bank charging should you desire. DIYW, FF | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 33 Registered: 11-2008 Posted From: 76.64.242.62 Rating: N/A |
Uggghh! Sounds like I'm into another huge can of worms. And just when I thought I might be able to actually USE this thing instead of getting it READY to use. Has ANYBODY kept the original air? If so, are they happy - even marginally - with their choice? And Fred, you say: "The shaft has to be removed every winter season in order to have better safety, should the clutch setup fail. It fails to ON, not a great prospect at 70mph." But what HAPPENS if that occurred? Golly, just what I need... something else to worry about while I'm driving down the road. And I can't remove the shaft in winter 'cause I'm not planning to be in winter... if I'm in 'winter' it'll be for about as long as it takes to get to 'summer.' But for safety... now that's a huge factor. How hard is it to remove this shaft... wherever it is? If push comes to shove and I gotta remove all this AC stuff, can I keep the coach HEAT by itself? I dearly LOVE that setup - kept us toasty the whole first winter (working on the interior). And driving down the road, even in sub-zero conditions, it keeps the bus warm from front to back. Well, Fred, this is not great news for me but I surely do appreciate your expertise. As they say, forewarned is forearmed (somtimes). Nellie Wilson | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 638 Registered: 8-2006 Posted From: 76.91.197.153 Rating: N/A |
Nellie, Just another opinion, and just like something else, everybody's got one. It all boils down to what you want to do with your bus. It seems like everyone has broken it down into thirds, one being the satisfaction gained from doing the conversion yourself. One in getting "THERE," and one in "camping there," boondocking if no hookups. Whadya wanna do? (I'm still suffering from John, but its not a bad thing!) This is an air conditioning contractor speaking, so bus HVAC doesn't baffle me. All three parts are important to me, but I really like to drive, and be comfortable, whether driving or parked. My bus has a LOT of bay space, so room underneath isn't as much an issue for me as some. Many people buy a bus with air that doesn't work, and throw out at least the cooling portion to use the condenser space for a gen. If the coach heat portion goes, you get some more space under. Most people leave the driver's heat & defroster, for obvious reasons. Some put an automotive size compressor in place of the bus size, and keep the driver's cooling. That takes a much smaller condenser stashed someplace. Buses distribute their heated or cooled air under the windows, which is good while it is a passenger carrier with the engine running. Once it becomes an RV, it sucks! Look at the wall thickness, which is inner and outer skin, insulation, and duct space. Needless to say, there isn't much room for insulation! Busses have about 6-9 tons of capacity, which they need for solar gain thru the glass, the thin walls, and the heat given off by the passengers. You will greatly reduce your heat load by getting rid of windows, reducing your passenger count by at least 35, and foam insulating your walls. The conditioned air is run in a center 'spine' duct front to rear, so shorten the sideways runs and bring them up thru the floor in each of the rooms. I must violently disagree with Fred on a couple of issues. One, MANY MCIs (including mine) were made to use R-22, which is still being made, and will be until 2020. There is already a "drop in" replacement for it on sale, for use after that. Two, drop in replacements DO NOT require oil changes. IF your bus was R-12, there are at least five brands of drop in replacements that have been sold for years. Ask Nick about Hot Shot, Nu-22, One Shot, Suva, 409A, etc. I am very much against a 134A conversion! The coach heat definitely doesn't have to come out, unless you're really desperate for bay space, and IMNSHO you'll have to replace it with something that takes up space in the bus (a furnace.) Now, how are you going to start your eng on a cold day? Keeping in mind that you are also keeping yourself and your domestic water warm? Webastos, Proheats, etc come to mind, as with them, and an exchange loop water heater, you arrive with free hot water. Block heat is quick and easy, as is stationary indoor heat with some baseboards. Freon leak detectors have been sold for many years in many styles, and all of the newer ones will locate a leak with a rate of 1/2 ounce per year. Yes, when R-12 was 69 cents a can, you just added, but not any more. Now, the local A/C shop is the best place to take a leak! Many people pull the bus air, and add roof or basement air, and run it off the main alternator thru an inverter while running. Others us a gen. The advantage to this is "plug and play," its quick and easy, and gives you cooling while parked as well, whether plugged in or gen. Sean made electric air for the driver's area of his bus, another nut put a 5 ton scroll compressor in place of the engine driven comp with success. A contractor buddy has electric central aired two busses for customers. Takes up no additional bay or roof space, does the whole bus evenly and quietly. A whole bunch of suggestions, with an obvious preference, and I don't mind an e off either. A whole lot easier to send compressor pictures! George | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1455 Registered: 12-2000 Posted From: 67.181.166.160 Rating: |
Nellie - Relax a little. What Fred was saying about the shaft AC, clutch, etc. only applies to earlier GMCs. MCIs, as you know, use a belt-driven compressor with an automotive-type clutch, a completely different set-up. IBME that the most common failure of the compressor on an MCI was the belts, at least in revenue service. Original bus HVAC has been left intact by some of the major commercial conversion companies, but, again, that's becoming more rare. Especially now that the thinking is toward the most energy efficient systems, which often revolves around improved insulation - something you will have problems achieving with OEM HVAC. Depends too, as others have said, on the climate you tend to frequent the most. Some folk have built their coach with no A/C at all, others have taken out the heater completely, except for the defrost. Lots of options. As Fred says, "Do it YOUR way!" FWIW & HTH. . . | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 573 Registered: 10-2006 Posted From: 66.82.162.17 Rating: N/A |
"Two, drop in replacements DO NOT require oil changes. IF your bus was R-12, there are at least five brands of drop in replacements that have been sold for years. Two, drop in replacements DO NOT require oil changes. IF your bus was R-12, there are at least five brands of drop in replacements that have been sold for years." The problem with the drop ins is they are 15% to 40% WORSE as refrigerants , so cooling in hot weather , even if you do make up for the leaks weekly , gets Iffy. Some gutsy folks switched to 90% propane 10% Butane as refrigerant , same old oil. Better than the drop ins in terms of efficiency but leaking 5 pounds of flamables a week is "much ungood". The special 400 rpm low idle was to reduce the loads as an 11inch truck clutch would pick up the Carrier compressor.Think og what happens at speed , the compressor rips loose and spins while still in the bay , a short time. "Buses distribute their heated or cooled air under the windows, which is good while it is a passenger carrier with the engine running. Once it becomes an RV, it sucks! Look at the wall thickness, which is inner and outer skin, insulation, and duct space. Needless to say, there isn't much room for insulation!" We chose to keep the distribution system for the propane heat , stock insulation or not it works like a charm, and since we sleep cool, and temp up for daytime , its great to watch the moisture (yes we breath in the coach) lift off all the windows . Basement air is a bit more complex as a high up return duct is required. FF | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 880 Registered: 12-2000 Posted From: 71.54.29.215 Rating: N/A |
As far as Bus AC, depends on how you use your bus. Of all the time we spend in our bus, the bus engine is running less than 10% of the time. That means that, at the most, the bus AC can only be used less than 10% of the time. We felt all that bus AC space was much more useful to us than an AC that could only be used less than 10% of the time. We did keep the bus dash heat. We do many weekend trips and usually 1 out-of-state trip that last about 2 months each year. WE stay in the SE and this past fall trip we drove a total of 1800 miles. At an average speed of 45 MPH (including going through small towns), we spent approx. 45 hours on the road in 8 weeks (1344 hours). As you can see, we would have been able to use the bus Ac for a very small percentage of the time. Jack | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1404 Registered: 12-2000 Posted From: 76.68.123.169 Rating: N/A |
Hello Nellie. There are a number of us who have kept the stock HVAC intact. As noted, there is a cost in $$ and space, and you still need to add AC for camping. However, hard to beat the pull down capabilities of that original AC after the coach has been sitting out in a sunny parking lot, closed up all day, heat soaking, while you were out recreating. A Canadian will definitely want to strongly consider keeping the stock coach heat, as you already identified, it works well in the real cold. Also, note, many of our members are from the south, or plan to be in the south, and that changes their design criteria for heat. We need to consider the ability to raise the temperature by 100 degrees Fahrenheit, between inside and outside. It also changes their design criteria for AC too. In the desert, they're looking at dropping the temp some 50 degrees from outside to inside. The used coaches we typically buy have been run hard, and more than likely been poorly maintained by their last commercial operator, due to scarce resources. The failure of the coach AC may have been one of the deciding factors to sell the coach. Returning the coach AC to leak free operation is not impossible, just a bit expensive. Compressor shaft seal, hoses, condenser and evaporator may all be readily replaced, for a price. Best might be to have your system evaluated to see where it is leaking? Then decide from there whether you want to spend the cash. Perhaps a local HVAC guy will hook up his machine and go leak detecting for you for some weekend cash? With the bus industry de-regulated in La Belle Province, Quebec is full of HVAC guys who have a little bus background. I had a bus fixed by a guy who was then building those cheese sheds, very late one Friday night in Sherbrooke... Yes, seems that building the bus takes precedence over using the darn thing, doesn't it? happy coaching! buswarrior | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 639 Registered: 8-2006 Posted From: 76.91.197.153 Rating: N/A |
Fred, Your description of drop in refrigerants' performance differs greatly with the manufacturers' data. By your post, it is also obvious that you don't know what the main ingredient is in all of the drop in refrigerants! Propane it is, with just enough of some of the other ingredients in R-12 and R-22 to make it non-flammable. You haven't replied to the fact that her bus may well use R-22, and her bus definitely never had a low oil pressure interlock, or the shaft you describe as needing yearly alignment to avoid catastrophic failure. If Nellie has a problem, all she has to do is take off the belts... ? | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 34 Registered: 11-2008 Posted From: 74.13.196.236 Rating: N/A |
Still digesting all your EXTREMELY helpful input, but just couldn't resist a quick question to George (MC6). Okay, George, I'll bite. What's "something else" that eveyone's got? And who is 'John' and why, dear George, are you still suffering? Nellie Wilson extremely had | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 578 Registered: 10-2006 Posted From: 66.82.9.99 Rating: N/A |
"Your description of drop in refrigerants' performance differs greatly with the manufacturers' data." Sure the guy selling always has a "great story". I have a real moneymaker Bridge in Brooklyn for ya. For a more realistic look at how well the replacements function , get a replacement parts book from a supplier and see how the compressor packages are RATED with the various mixes. Could be an eye opener , FF | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 643 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Fred, In your post of Dec. 1, 635am, you say "Some gutsy folks switched to 90% propane, 10% Butane... same old oil...Better than the drop ins in terms of efficiency..." Apparently you did not read my post of Dec. 1 1048am with understanding! It does say "...Propane is the main ingredient in all drop in refrigerants, with just enough of the ingredients in R-12, and R-22 to make it non-flammable." Please consider a couple of other things that were published before, namely the fact that the subject bus has a totally different type of compressor system than the one you warned about, AND that this bus is being converted, which will remove the heat load of about 35 passengers, and the solar gain of at least half the windows. My EPA UNIVERSAL Freon Certificate number ends in 280571, and was issued on 11/1/95. "Sure the guy selling has a ""great story."" Well Fred, I'm the guy USING, also the guy who doesn't get paid until it works, and what I do usually does! G | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 74 Registered: 10-2007 Posted From: 206.45.93.160  Rating: N/A |
If your factory A/C is working , leave it. If it isn't get an estimate to see how much $$ to fix it. If it's with-in your budget , fix it , keeping in mind that the system has some age to it and will need more $$ to maintaine it in the future. If you don't want to fix it either put in a roof top or basement A/C. Myself I took mine out. When I bought my bus, charged the system and found a leak in the condensor, I looked and the shape of the hoses etc and my question was answered. Pull it out run the gen and stay cool. This way I can use it and maybe someday improve it as time and $$ comes along. Have fun and don't get overwhelmed, use the bus no matter what stage your at and most of have fun! | ||
| K.J. Franklin (Slow_rider)
Registered Member Username: Slow_rider Post Number: 25 Registered: 8-2006 Posted From: 98.204.7.118 Rating: N/A |
Nellie, Contact Nick on the other board, he is a licensed HVAC contractor and has the original a/c in his bus. I will tell you up front he is very much in favor of keeping your bus a/c. But he can give you an idea of the maintenance costs involved. Frank | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 53 Registered: 11-2008 Posted From: 76.68.203.213 Rating: N/A |
Well, I'd say this has become quite a spirited dicussion! And can't tell you how much I appreciate all the input. Following Grant's advice ("Have fun and don't get overwhelmed, use the bus no matter what stage your at and most of all have fun!"), I'm thinking I'll keep the original AC, at least for awhile and see how things go... maybe look for replacement parts from folks who are tearing theirs out. And thanks, Slow Rider, for the tip. When you say Nick's 'on the other board' I guess you mean MAK? George MC6 is top of the line (in my book, anyhoo) but I'll see if I can track down this Nick fellow. I much prefer this board but, hey, nothing wrong with the other one... probably just not used to it? Nellie Wilson |
