Air Leak

[Randy Perry]

I've had a leak for a few years that hasn't been an issue until recently when the engine quit on me and had to have her towed. My (truck) machanic got me running and I asked if he was familar with the airbag system on these coachs and he replied he was. He said he looked at this that and the other but couldn't find the leak. It's the right side bag thats effected and will take a day or two to deflate. Anybody have any places to look for a small leak? or the best way to look for it besides applying some soapy water on various locations!

[George H. Wall]

First place I would look is around ALL connections, which is the weak spot in these systems, with all the movements. Use soap and water spray bottle, only way I know!!  

[Arden Smith]

Might also want to check around the leveling valve bodies as well as mine were a composite or plastic bodies and had metal fittings pressed into them, The bodies on mine cracked around the metal fittings and leaked quite bad, I replaced with full metal bodied valves.
Arden Smith

[Randy Perry]

Thanks George and Arden! Sounds like I'll grab a spray bottle of soapy water and spend the day under the coach!

[Gerald Farris]

Randy,
Be very careful while under the coach. If you disconnect an air line for the suspension, it will come down on you. Suspension work can be very dangerous if proper precautions are not taken.

Gerald

[Randy Perry]

Thanks Gerald, I'll throw some blocks under it!

[Randy Perry]

So I heard a leak and traced it to, we'll, I'm not sure what it is? Has a larger inlet iine with a smaller (green) maybe 1/2" outlet hose that's leaking. Can't tell where either come from or go to! Anybody tell me it is and could this air leak the cause of my right bag deflation issue?

[Edward Buker]

Randy,

That is the receiver dryer. It removes moisture from the compressed air and keeps the air system components free of excess moisture. That unit will purge air along with some moisture when the compressor reaches a preset pressure and shuts off. Some units will slowly shut off the purge cycle and some have a sharper cutoff. That is normal.

After the pressure is built and the compressor shuts down there should be no air leakage after the purge cycle plus some amount of cut off time, say 30 seconds or less. If it is just sitting with the engine off and you hear constant air leakage something is wrong, either a valve that is worn or not seating properly, or a hose or fitting. There is a canister on the top with an Oring seal that contains a desiccant. That could also be a leak source but that is not that likely a source.

If you or anyone is going to work on this unit, all of the air system pressure should be released first using the air purge drain valves for the system for safety reasons.

Later Ed

[Randy Perry]

Ed, there is an air leak on the green (outlet) hose at the fitting. Would this be my problem with just the right side deflation?

[Edward Buker]

Randy,

I am not sure. The green hose may be the outlet and you should not have any leaking coming from any external hose fitting. If the air tanks get depleted then there is no source to supply additional air. If the air spring system then continues deflating, but the right side of the coach is heavier, it will drop more then the lighter side and inflate slower as you bring the pressure back up in the system. That could be a way that the air source piping could contribute to one side dropping more than the other. I'm not sure if this leak would be the source of your right side depletion but fixing this would give you the answer. It may also be the right side rear leveling valve or an air fitting at one of the air springs. Hope this helps.

Later Ed

[Randy Perry]

Ed, I did find that by moving the green hose a slighty, it seemed to stop leaking. So I took a zip-tie and was able to keep it in that position! Its been 20 hours and the coach hasn't dropped even an 1/8" of an inch!! Sounds like I found the culprit and turns out it was a cheap fix   if not, at least a temporary one!! Thanks Ed and Merry Christmas to you and all!!

[Edward Buker]

Randy,

That is good news. Usually air leaks are not that easy to find. Any air leak, where moving a hose temporarily fixes it, means that joint and seal cannot be relied on. Air leaks are serious issues given many systems, especially brakes and suspension rely on this constant air supply. Have a good truck shop or someone familiar with air fittings and systems fix this leak sooner rather than later.

Later Ed

[Doug Allman]

Arden, had same problem with plastic components as you, numerous times. I believe it comes from any very small amount of moisture left that freezes during winter and cracks plastic valve body. For future reference where did you get the all metal valve body?

[Arden Smith]

Obtained Haldex valves from a reputable truck parts place in Everett, Wa.

[Matthew Harger]

Newbie question....our new to us 98 Patriot is our first motorhome.  The airbag suspension is also a first hence the lack of knowledge about it.  From reading this post am I understanding correctly that once the air suspension fills itself  with air then it should remain filled indefinitely until the air is manually dumped via the button on the dashboard?  I'm pretty certain the air is completely out of our suspension system within hours or the engine being turned off.  Should I start checking for leaks to deal with or is this normal?   Thx