BCM Community
Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Branderson on March 25, 2019, 06:47:22 AM
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I started her up yesterday and the front bags are not filling up. You can hear the air which I immediately knew something was wrong. I don't think the air is even getting to the air bag but I have a mechanic coming to check it out hopefully today.
My question is if it's still drivable when the front bags are not up? I didn't want to take a chance and ruin the fenders when turning b/c it looks like it could touch. I figure it's best to have the mechanic come to me.
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About the only thing you should do is drive it up onto ramps at your location. You probably will damage fenders/air bags/possibly steering components.
You could jerry rig an air supply from the drivers seat directly to the height control but if you are going to go that far you may as well just fix the problem.
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Your air dryer s purge valve on the bottom of the long cylinder on the from wall of the front wheel well is probably open and leaking all the air out. If you can't air up in 90psi your brakes will still be locked. Try taking a stick and slap the bottom of the air dryer to see if it will close without going under it. You will need to service it because sound like it hasn't been done unless you live in cold country then it might be frozen and you can slide a small heater under it to thaw it out. :)
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The mechanic is bringing ramps so he can get under there. Thanks for the input. My gut said not to drive it, I'm glad I didn't.
The PSI guage got to the normal setting and the rear was aired up just not the front. Over the phone the mechanic thinks it might be a line that detached but he's not sure.
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If rear aired and the front didn't could also be a check valve between the accessory tank and the front leveling valves.
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Okay turns out the air line broke. Apparently it was plastic or a plastic part that broke so he's going to replace it with a copper line. He pinched it off with a zip tie and it aired up properly and I will drive it to his place tomorrow.
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Preventive maintenance opportunity...
Go find the rest of 'em and change 'em out.
In the shop on purpose, or on the road on your own...
Happy coaching!
Buswarrior
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That's a good point warrior. We are going to Talladega for the races next month and I don't want any mishaps b/c there's not much out there and this will be my first dry camping with it.
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Heres under and see where the line broke. It was only half broke but he cut it so he could zip tie it yesterday. He put in a copper line so hopefully that lasts.
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That line does not even looks like a DOT air line.
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No mater the type of piping, be sure it is protected from movement/vibration where it carves through the pylon, and anywhere else it could touch anything.
Vibration rubs holes in EVERYTHING...
Happy coaching!
Buswarrior
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Is that line for the ice maker?lol If I were you, I'd check all the other lines for that material. It's not designed for that use.
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And if replacing with copper air lines, be certain to use the correct type of copper tubing and brass fittings. The flare fittings from Lowes or Home Depot are NOT the same as air line fittings, and the copper line needs to have adequate wall thickness to withstand the vibration and pressure.
Most decent parts suppliers will have the correct air line fittings.
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Paradise fire victims we gave our bus to just called with same issue. Right front side won't fill. Air pressure 100# and they can't hear any leaks. They're in Redding. Any shop up there that could help? Also, could it be the leveler valve?
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I think not hearing the leak is important b/c I could hear it big time. I wonder if it's more of a check valve issue.
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I've seen 'em simply be stuck, and a short bit of "agitation" by moving it and it springs up.
Sitting is the DEVIL for these worn out old whores.
Achieving some sort of normal pressure is half the battle, bent leveller arm, seized valve, ancient lube inside finally gone hard enough to block movement...
The only reason they go, is if they keep going. Park it on dirt for months at a time.... trouble.
It ain't yer Dad's Oldsmobile...
Happy coaching!
Buswarrior
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My thinking is to (1) make sure the leveling valve is moving freely. (2) If that doesn't do anything try blowing out lines (100# should do that, but I guess a big gob of old hard crud could block it (3) or bad check valve.
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There is only one leveling valve on the front of the GM's. It controls both bags. Two at rear, one for each side. If right rear isn't filling, it can tilt front of coach, giving the inpression that there is an issue at the front.
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Paradise fire victims we gave our bus to just called with same issue. Right front side won't fill. Air pressure 100# and they can't hear any leaks. They're in Redding. Any shop up there that could help? Also, could it be the leveler valve?
From my understanding, if it is just one corner leveling valve not the first thing to look at. When I have had one corner not building air it was either a lose air line connection at that corner or a leaking bag.
The front leveling valve controls the front-to-rear height, so two corners would be down. The rear valves each control the height of the front & rear corners on that side, so again two corners would be down.
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So the problem has to be downstream from a check valve on the right front?
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So can a 4104 be towed without removing the drive shaft or releasing the brakes?
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Releasing the brakes and pulling the axles.
or removing the driveshaft.