| Author | Message | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 441 Registered: 1-2010 Posted From: 68.151.225.213  Rating: N/A |
It warmed up to about freezing today so I thought that I might fire up the coach in preparation for some things I want to do to it this week. It started good. About 20 seconds after start up the high pressure relief valve popped about 5 times making me think that the air line was frozen but then it stopped popping and the coach started to air up. On high idle the air pressure built up to the point where the low air warning device stopped beeping. I tried to release the park brake but the button wouldn't stay up so I cycled the brake peddle twice then tried to reset the park brake again, at this point the low air warning came back on with both needles on the gage at about 100 lbs. Again I cycled the brake peddle several times and manually fast idled the engine until the low air warning went off and the needles went to the 120 lb. mark and the compressor cycled off. Again I tried to release the park brake, this time the button stayed up and the park brake light on the dash went out. I wanted to back the coach up so I tried to put the transmission in reverse ( Alison B500). The transmission wouldn't engage in either forward or reverse. Then the low pressure warning came on again but both needles on the pressure gage were still well above the point where it should be coming on. Is this just a frozen air line somewhere? Or should I be worried? If it is a frozen line any ideas on how to locate it ? Would a frozen line somewhere in the park brake system not allow the transmission to engage? Any ideas would be appreciated. Les | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 442 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
A little more info! The compressor cycles off above 120 lbs closer to 130 lbs With the compressor idling, there is no movement of the air pressure gage when I cycle on and off the park brake so I am not sure if the park brake is actually disengaging or not. I have heard the air dryer cycle twice since starting the coach so air must be getting through the system | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 307 Registered: 5-2007 Posted From: 174.91.225.183  Rating: N/A |
I think a bunch of stuff is frozen. Did you put some alcohol in the air system before it got cold? WATCH OUT if you have a air dryer heater you have to put the alcohol downstream of the air dryer. This is a pretty common problem on buses. if you ned the bus put it in a garage to warm up, if you can wait, some warmer weather should clear up the problems (especially if they weren't there before the deep cold) BTW you do drain your air tanks/have working auto drains? | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 604 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
Les Have you used a shop compressor in the past to preair your coach? If so, you could have moisture trapped in the system and it was plenty cold this past week, -37C a my house, for everything to freeze. | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 443 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Did drain the wet tank and got a small amount of moisture out of it. Fair clean with no oil in it. Can't move the coach because the transmission won't go into gear. Would like to know how the park brake and the transmission interact | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 1313 Registered: 8-2006 Posted From: 76.94.211.60 Rating: N/A |
Les, The parking brake and the trans don't interact, but if you have an electronic shifter, it moves the actual trans lever with auxiliary air pressure. It sounds to me like you are frozen at your protection valve, which isn't allowing any air to the auxiliaries. Is the bus airing up? Horn honk? These will tell you where to "look" for a frozen component. Are you also sure the trans isn't engaging, and the bus just won't move because the parking brakes are applied and/or frozen to the drums? G | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 444 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Hi George I would guess that the shifter is electronic because all I have to shift is a key pad. I think that the auxiliaries are airing up because the door, windshield wipers etc are all working. The coach is airing up but I did notice that when I tried it last that the low air warning was sounding and the entry door wasn't working even though the gage on the dash still read 120 lbs of air pressure on both needles. Shortly after starting the engine the low air warning stopped and the door etc would work again but the transmission still wont go into gear. The transmission is not going into gear for sure because the display on the shifter pad remains indicating N for neutral. Where would I look for this protection valve and if the air was not getting to the shifter would the display pad for the shifter still indicate that the transmission was in neutral? If so that very well could be the problem. Would adding some alcohol to the wet tank help or would that cause more problems with the air drier. One of the things that I want to do its to service it and the point of getting the coach going today was to get it up high enough to get at the dryer Thanks Les | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 118 Registered: 7-2006 Posted From: 207.34.166.7 Rating: N/A |
Les, what I think is that it might take another day or two for the bus to warm up. The air outside is near 0C, but the whole bus, having been at -20, -30 for a few days, retains a lot of that low temp for a long time. So leave the bus alone, go for coffee or a beer, and get back to it tomorrow or the next day. Or, if you are in a hurry, tow it into a warm shop. Good luck, JC | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 445 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Well, JC, it is like the old joke about the two buzzards. One said to the other "patients my butt... I am going to kill something" Ya I might have to hope that it defrosts but warmer weather has been sparse around here lately. How did you make out with that cooling blower I sent you? I would still like to get to the connection between the air issue and the transmission not engaging if there is one Les | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 623 Registered: 3-2006 Posted From: 216.198.139.38  Rating: N/A |
Les If all you have is a key pad you don't have a need for air to shift. Try pushing all the buttons a multitude of times and see if it starts to work. You will have circut breakers or fuses for the transmission computer. Check them. Mine will do this once in awhile and just playing with the buttons it starts to work. Like JC says wait a few days starting it and let it heat up as much as possible as you can't work it. They need exercise to produce heat. Bill | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 1364 Registered: 8-2006 Posted From: 184.10.153.249 Rating: N/A |
The B500 is tied to the parking brake if the brakes don't release the transmission will not engage,no air is needed to engage the transmission it is all electronic but tied into the brake system. I spent 2 days looking for a bad switch on a bus at NW Bus sales the parking brakes would release but good luck (Message edited by luvrbus on January 22, 2012) | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 119 Registered: 7-2006 Posted From: 207.34.166.7 Rating: N/A |
Les, I haven't done anything with that blower. I am just storing it as a spare in case me or someone else needs it. JC | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 446 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
So how and where is the tie between the park brake and the transmission. Is there a safety switch that doesn't allow the transmission to go into gear if the park brake doesn't disengage? I have the parts and maintenance manual for this coach and cant find anything that indicates a switch but it does make sense to me if one exists. Could heat be applied to it? It is humbling to be reminded of how little I know about this main component of our coach. School will commence Les | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 1612 Registered: 3-2007 Posted From: 76.4.123.74  Rating: N/A |
Les If you have a space heater and some plywood,blankets you can build a wall around the coach and let the heater blow under the coach and it will take a little time but it will thaw all of it out. I have a 100,000 btu heater and have had to use it and just block off around the coach and let her get warm Oh don''t let it get too close to anything that will burn Gomer | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2241 Registered: 12-2000 Posted From: 174.89.178.23  Rating: N/A |
Well, I think I wrote a post back there in the fall... The title was/is: Who will scream "MY BRAKES ARE FROZEN"... http://www.busnut.com/bbs/messages/11/61598.html?1317156627 Les, you posted the transmission wouldn't go into gear last winter too. How often has it done that since then, and what if any maintenance have you done to it? You avoid putting brake alcohol in ahead of an air drier not because of the heater, but because it turns the desiccant material into mud, which then can foul the purge valve making a leak, and can plug the check valve, blocking air flow to the rest of the system. Les, make up a pumping rig and put a litre of it into the wet tank and leave it there for now. happy coaching! buswarrior (Message edited by buswarrior on January 22, 2012) | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 1365 Registered: 8-2006 Posted From: 184.10.153.249 Rating: N/A |
I don't know where yours is going to be located but I spent 2 days at NW Bus Sales finding a bad switch on a DL 3 the parking brakes would disengage but with the bad switch would not swift, it was in the left side of the dash had 2 wires and a 1/4 inch line | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2242 Registered: 12-2000 Posted From: 174.89.178.23 Rating: N/A |
Les, there was no air switch labeled as belonging to the transmission in the schematic you sent me last winter. Luvrbus, did you get any sense whether that switch did anything else besides signal the transmission? Les, check the wiring schematic for the transmission circuits, to see if that will help point in the right direction, whether it piggy backs on the switch that activates the brake lights when the parking brake is applied, or whether it has been left off the air schematic all together. happy coaching! buswarrior | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 447 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Hey BW you are right I did have the same problem last winter. It seemed to solve its self and wasn't a problem the few times that I moved the coach this last summer. As far as maintenance goes I must admit that all I did was to drain the tanks several times. My only excuse is a major foundation repair on our rental house left me with no Bus time. Our coach is a D3 not a DL3 but I would guess they use the same system. The brake lights are working properly. They are on when the park brake is set and go off when they are released as does the park brake indicator light on the dash. If the weather stays nice I am going to see if I can move the coach with the suburban to see if the park brake is actually disengaging. I can put antifreeze into the wet tank. I guess no harm done because the desiccant is going to be changed anyway | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 1366 Registered: 8-2006 Posted From: 184.10.153.249 Rating: N/A |
Flash the codes through the shift pad if you don't own a Pro/Link it will tell you fast why it won't engage,the B500 is one smart transmission lol | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 384 Registered: 2-2007 Posted From: 66.87.74.15 Rating: N/A |
Those trannys won't engage below a certain temp. | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 448 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
I did try to pull codes from the transmission by pushing the up and down arrows at the same time, No codes With the engine running and ambient temp at above freezing I think that the transmission would have warmed up | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2243 Registered: 12-2000 Posted From: 174.89.178.23 Rating: N/A |
Les, with the coach being yard bound for an extended period, there will be moisture in all sorts of places that is frozen, and anything that moves will be inclined to not do so, doubly so with it being cold. I'd be inclined to just leave it lay. The stuff that gets freed up will just stick again without use. Getting the coach out on the road and run solves/prevents trouble we can't even begin to list. Don't feel badly, mine has been unavoidably yard bound for longer, life gets in the way of hobbies! I have been in the presence of dozens of B500 equipped coaches in -30C/-22F that fired up and drove away. Webasto/Proheat equipped for the engine, so perhaps once started, the juices exchange sufficient heat to keep the sensor happy? If the B500 didn't work in the cold, you can be sure every charter driver around up here would be telling stories, either his own or someone else's! Yes, I agree, the B500 is very smart. Les, you may want to plan to add a Prolink to your tool box, it will only be a matter of time before something in your drive train will need you to do some analysis, and it will pay for itself instantly at that moment. Lots of busnuts on here can help you if you have the scanner, and it's harder to rip you off when you know what's going on. happy coaching! buswarrior (Message edited by buswarrior on January 23, 2012) | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 449 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
I didn't get a chance to look at the coach today. I hope some warm weather will solve the issue. I don't have a scanner... YET!!! But I can see it on my self medication list. When I get the coach mobile I foresee a short (under 1000 mile) trip in its future. I have a mobile service coming out for an other issue, will see what they know. Thanks guys. Stay tuned and I will let you know what happens Les | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 451 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
I got anti freeze into the wet tank and ran the bus for about 1/2 hour cycling everything I could get air through. Still no transmission luck. I have someone coming with a scanner and some experience with Alison transmissions. Hope to get some definitive answers | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2247 Registered: 12-2000 Posted From: 174.89.179.92 Rating: N/A |
Good report. For the congregation, how much did you get in, and by what method? You can just leave the alcohol in there now until spring, and drain ALL of the tanks dry once the freeze is gone. Sharing a detailed list of what comes up on the scanner would be interesting for the rest of us too! Have paper and pencil at the ready. (For those southerners, a pencil will work below freezing, pen? not so good...) happy coaching! buswarrior | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 452 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
About a liter... that is Canadian for quart... Blown into the wet tank thru the drain valve using 1 inch copper pipe with air fittings on each end and shop compressor. Does this mean that I can't play with that part of the coach till spring?... It is snowing today. Spring might not be till May | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2249 Registered: 12-2000 Posted From: 174.89.177.124 Rating: N/A |
Since we cannot determine for sure what is or isn't stuck, or for what reasons, leaving the alcohol in the tank to migrate helps rule out freezing. It will keep what is working to stay that way, and if you operate the coach air system on a warmer day, might migrate through and prevent it from getting frozen again elsewhere when it cools back off. Pretty much a shotgun approach with a dose of Hail Mary thrown in for the religious part. Carry on as if it wasn't there until the spring. happy coaching! buswarrior | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 453 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Tell it to me brother B.W. Had a mobile mechanic look today. He claimed to have extensive alison experience... OOPs realized that he didn't know much more than I do from the reading I have done. I think that I am going to let it sit for a week and then try it again. We are forecast to have a nice run of weather this week. I called Waterious today and for $142 per hour they can send out the mobile unit with diagnostic to determine problem. They seem to think that the problem might be electrical rather than air related At least the fellow that I talked to knew that there is 24 wires in the plug on the computer (I counted) We will see what happens Les | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 629 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Les I sent you an email with an attachment from the 700 series transmission book. I couldn't get it to download to here. Bill | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 630 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Les I forgot to mention that they are things to check when you do not get a code from the ATEC computer but the transmission will not go into gear. It stays in neutral. Bill | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 454 Registered: 1-2010 Posted From: 68.151.225.213 Rating: N/A |
Thanks Bill. I got your e-mail Les |