| Author | Message | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 165 Registered: 11-2008 Posted From: 74.13.197.93  Rating: N/A |
As some of you know, I finally got 'Nomad's Land' (my bus)'running and airing up again. But while monitoring the air pressure, I noticed some psi loss when there shouldn't have been (no air appliances were being used). I walked around, listened for leaks, but heard nothing. After I shut her down, I opened the engine compartment to cover her with a blanket (I always tuck her in for the night) and hear psshhhh. I located the leak... it was dark so I couldn't tell for sure, but it seems NOT to be from a line or a valve. The air is escaping from the 'business end' of the piston that tensions the belts to the air conditioner compressor. I'm going back today to check that, but here's my question: Regardless of exactly what is leaking, and since I've decided to remove those belts anyway, can I simply plug the air hoses that feed the piston and deal with the leak later (when I put the air conditioner back into service)? To better explain, I'll try to upload a photo of this piston.  Wow! That was fun... never posted a picture before. Now I can just go wild... expect a lot of future photos. Thanks, Nellie Wilson | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 690 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Yes. | ||
| Glenn Williams (Glenn)
Registered Member Username: Glenn Post Number: 183 Registered: 6-2006 Posted From: 216.163.56.194 Rating: N/A |
Go ahead and remove the belts and disconnect the line to the piston and cap the air line. It is no problem at all. Before you do, give a listen closley to see if the leak is from the air line/junction, or if it is air leaking from the piston itself. Good Luck! Glenn | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 168 Registered: 11-2008 Posted From: 70.52.100.254 Rating: N/A |
Glenn- The leak is definitely coming from the piston. I had a buddy (Neil) come over. Neil's no bus guy, but he trained at Detroit Diesel back when Heck was a pup... back when the 8v-71 was DD's state-of-the art power plant... and he's been truckin' or wrenchin' ever since. (Except when he backs me up on his INCREDIBLE drums). He reckons there's less than 10 psi supplying that piston. He also questions whether the 'leak' is actually an OEM exhaust? The hole expelling the air seems machined (as opposed to rusted or corroded). Neil suggested I ask you guys if an operational A/C is necessary for the coach heating, defrosting, etc. What he's saying (in a nutshell) is to 'Avoid major modifications before a long trip - unless you're absolutley sure what you're doing.' Well, I'm not ABSOLUTELY sure. And Neil reckons the 'leak' (if it IS a leak) is so small it's hardly worth messing with... at least for now. Whatta ya think guys? I'm pulling out on Thursday... Nellie Wilson | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 758 Registered: 7-2006 Posted From: 72.146.76.23  Rating: N/A |
I guess the question should be asked: If the piston isn't keeping tension on the belts, will you run the risk of the belts being tossed off the pulleys during high revs? And, should you remove the belts, block off that air line to the cylinder, and be happier later? Ya'know gal, you really oughta' have that drummer/wrench guy inspect the rig, bumper to bumper before you roll on out. I love reading your posts and looking at your uhhh... picture... but with each post, you seem to tell us of a new problem with the rig! It cost me 200+ to get "winched" out of some sand at the storage facility, about two miles from the tow guy. You really don't want to have to get towed. It's a wallet wrenching experience. | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 175 Registered: 11-2008 Posted From: 70.52.103.80 Rating: N/A |
Oh boy, John, don't I wish... ("... you really oughta' have that drummer / wrench guy inspect the rig, bumper to bumper before you roll on out.") You, my friend, are preaching to the proverbial choir. Touuble is, Neil's all stove up... can barely walk in summer and this weather just kills the poor guy. Sounds a simple thing though, doesn't it? Just go through the darn bus and fix what's broke. But you probably have several decent mechanics to choose from and seldom a weather related problemr? (Yup, I checked your profile.) But, John, you've no idea what it's like up here. Truly. The weather ranges from gruesome to brutal. I mean, I actually write songs about this cold gray gruel we call 'sky'... horrid weather! And the quality of help... fuhgedaboudit. Trust me when I say that this is America's backwater merging with Canada's tailing pond. I'm where I am now (here) because of 1) grim weather and 2) a caliber of help so abysmal as to make you weep. I'd tell you stories, but I'd rather not hurt anyone's feelings (this being a public forum and all). But I hear you loud and clear, John. I'm going on a wing and a prayer and just hoping for no breakdowns and for some work ahead. And maybe to sell a few albums along the way. I may freeze or starve or crash, but at least I'll be fighting for my little 'Place in the Sun." (Ever heard that song? Written by Stevie Wonder... I love it. If you'd like to hear it, I'll send you the version I recorded. Let me know - I can convert it to MP3 and send by email.) Anyway, back to the bus. The leak is tiny, (if it's even a leak). I'm so gun-shy at this point every little thing seems catastrophic. The air is holding beautifully and the belts are tensioned (and brand new). Still, I'd like to remove them and cap those air lines (maybe you read my previous post). Would you know if doing this (disabling the A/C) would interfere with OEM coach heat or defrosting? Hey, John, thanks for the feed back and for your concern. I'll be Florida-bound soon... where abouts are you located? Nellie | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 928 Registered: 12-2000 Posted From: 70.0.91.78 Rating: N/A |
"Would you know if doing this (disabling the A/C) would interfere with OEM coach heat or defrosting? I'll be Florida-bound soon" Nellie, Your bus heat and defrost will work as long as the 2 water valves in the engine compartment are open. Right now you will need that bus heat in Florida (at least for the next day or 2). Jack | ||
| Sammy (Sammy)
Registered Member Username: Sammy Post Number: 90 Registered: 8-2005 Posted From: 68.237.215.35 Rating: N/A |
If the leak is as tiny as you say, I'd leave it alone. Gotta remember when bus is running there's always an air suppply to keep tension on the belts. You can always spray some "Magic Leak Detector" (soapy water) on it to actually see how bad it is. Best of luck. | ||
| Nellie Wilson (Vivianellie)
Registered Member Username: Vivianellie Post Number: 180 Registered: 11-2008 Posted From: 70.52.107.72 Rating: N/A |
Well, delayed again. Not from any bus problems, but just the weather... snowing and blowing and very slick roads. 150 miles down the track it's 40 F but (like the old saw), I can't get there from here. At least not today. Waited all week for Thursday, and Thursday sucks (how can they so consistently be wrong on these weather reports?) Maybe tomorrow? Nellie Wilson | ||
| Sammy (Sammy)
Registered Member Username: Sammy Post Number: 91 Registered: 8-2005 Posted From: 68.237.215.35 Rating: N/A |
They didn't shake their"Magic 8 Ball" enough to guess the weather properly. | ||
| Tony LEE (T_lee)
Registered Member Username: T_lee Post Number: 46 Registered: 11-2007 Posted From: 41.214.146.63 Rating: N/A |
Inside that cylinder is a spring that will provide some tension on the belts even if the air all leaks down. When air is up, that cylinder is supplied via a regulator mounted at the control valve so the belts are tensioned correctly. MCI operating procedure state that the belts can be removed during winter after the AC is pumped down and isolated, so there is no problem doing what you suggested - remove belts and cap off the air line. There should be no significant air leaking out of the rod end of the piston. Needs new piston seals. There is one air system that does have a machined hole to provide constant air leakage - the left hand cylinder of the radiator blower outlet shutter (controlled by the airstat on the pipe running coolant to the LH radiator) has a controlled leakage so the shutters will open when the temperature rises. Otherwise they would stay shut forever. | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 6 Registered: 1-2009 Posted From: 24.129.235.190 Rating: N/A |
In the MC 8 manual before clutches came to the A/C conpressor you were to put the compressor to bed by 1. pumping the refrierant into the dryer and shunting the valve (to prevent leaking out the compressor pully seal while shut down)2. removing the two belts. I did do number two when driving in that first winter to save the wasted power of turing the dead headed compressor and all that "do nothing" wear & tear. Did not effect the heat system funciton at all. The third procedure was to discontect a wire on the system (like the A/C high/low/off switch to prevent the system from running the big 2 hp condesor fan for no purpose, if you misaplied the A/C control switches (something one of the dogs likes to do when pretend driving, that and the signal switch) Gee way to post pictures Nelle, I still haven't mastered the resize thingy to enable post a bus's profile picure, not even after downlaoding infaview device. Guess it is all in the way you were your blue boots! Even resorted to asking Ian for direction, sometning guys just don't do, you know! |