Suspension/Brake Air leak down on a DP

[Keith55]

My mechanic seemed fine with the amount of air my DP is leaking but I am not sure I am comfortable with it.

I got in today and the front was 0 while the rear was 65.

I am wondering if anyone has tackled this and where to start.

My guess is the 12 volt water "dispenser" is a good place to start looking. The valve could not be closing back up completely.

BTW, it's not at all like you shut the rig off and you can see it leak down but come back in a day or two and it has leaked down.

[amosnandy]

Originally Posted by Keith55

My mechanic seemed fine with the amount of air my DP is leaking but I am not sure I am comfortable with it.

I got in today and the front was 0 while the rear was 65.

I am wondering if anyone has tackled this and where to start.

My guess is the 12 volt water "dispenser" is a good place to start looking. The valve could not be closing back up completely.

BTW, it's not at all like you shut the rig off and you can see it leak down but come back in a day or two and it has leaked down.

Do you park it with the airbags up or down? I don't know about yours, but I rarely start mine that the low air warning does not com on for the front. I was told to always dump the airbags when parked. Just a little wind can rock the coach and just like going down the road the air bags are constantly adjusting. I also always put my put my jacks down after dumping the air to keep the pressure off the bags.

I don't think I would worry if you cannot hear an air leak when you shut it off with the bags inflated. After dumping and putting the jacks down, even for an hour my air in front is almost zero and the rear 65.

If it takes more than a couple minutes for the air pressure to come back up then you might want to worry.

[Ray,IN]

If your MH passes the air brake test the compressed air system is operating within normal limits.

[Keith55]

Thank you both for your responses. My mechanic did perform the air brake test so I can suppose I can feel comfortable that it is safe.

My Jacks were replaced by the previous owner (they were those Levelegs) and it no longer has an active "dump". The dump wires are laying in the fuse box compartment but never got hooked up. Previous owner disclosed that and said he couldn't figure that part out.

Usually what I do to get them to dump is extend the jacks and then retract. That apparently fills up the bags and "dumps a lot of air. Then I do the real level.

It does not take more than a couple minutes for the air to come back up and the mechanic said he couldn't hear a leak.

All good I guess. I just want to make sure I catch a leak BEFORE I am along side the highway!!

[wolfe10]

Originally Posted by Ray,IN

If your MH passes the air brake test the compressed air system is operating within normal limits.

Agree with Ray, but would state if a little differently:




If your MH passes the air brake test the air system is operating within ACCEPTABLE limits.



Acceptable may be a long way from "ideal". You can still have some moderate air leaks and still have your air system within DOT compliance.

[amosnandy]

Originally Posted by Keith55

Thank you both for your responses. My mechanic did perform the air brake test so I can suppose I can feel comfortable that it is safe.

My Jacks were replaced by the previous owner (they were those Levelegs) and it no longer has an active "dump". The dump wires are laying in the fuse box compartment but never got hooked up. Previous owner disclosed that and said he couldn't figure that part out.

Usually what I do to get them to dump is extend the jacks and then retract. That apparently fills up the bags and "dumps a lot of air. Then I do the real level.

It does not take more than a couple minutes for the air to come back up and the mechanic said he couldn't hear a leak.

All good I guess. I just want to make sure I catch a leak BEFORE I am along side the highway!!

To be honest, I would be more concerned with getting the "dump" air fixed. I like to get mine to settle all the way down, with the step in and check the situation BEFORE I put the jacks down. I generally put blocks under my jacks to minimize how far I have to extend them. Simple geometry. The shorter they are the less stress on them.

[Piros1]

My previous coach was a 2005 Country Coach with only HWH air leveling, no hydraulic jacks. It could set for weeks and still hold air regardless how it was parked. My Newmar Essex will leak off after a few days to a week. If you park your rig and it holds air overnight then you don’t have any major leaks and really nothing to be concerned about. If you are concerned I would get myself a spray bottle of soap and water and start at the main airline coming from the compressor and spray every fitting and valve until you have checked them all. That is about the only way you will find it if you can’t hear it. It never hurts to check for a piece of mind.

[Keith55]

Originally Posted by Piros1

My previous coach was a 2005 Country Coach with only HWH air leveling, no hydraulic jacks. It could set for weeks and still hold air regardless how it was parked. My Newmar Essex will leak off after a few days to a week. If you park your rig and it holds air overnight then you don’t have any major leaks and really nothing to be concerned about. If you are concerned I would get myself a spray bottle of soap and water and start at the main airline coming from the compressor and spray every fitting and valve until you have checked them all. That is about the only way you will find it if you can’t hear it. It never hurts to check for a piece of mind.

Yep - I think I'll soap and water back. Can't hurt. Of course, if I find the leak that is there, I'll probably have a heck of a time fixing it. Hopefully it's something simple and accessible. My guess is that it would be most likely in one of a few places.

[Piros1]

Be sure to spray all the valves, fittings, hoses, brake chambers, along with the connections. I’m sure you will find a few minor leaks, most likely nothing serious but you may be able to prevent futures failures.

[Keith55]

So 32 hours ago, I pulled my rig in and shut it off.

It's down to about 50 PSI now (32 hours later) and the suspension has sagged, of course, but is still elevated.

This seems safe to me and I am wondering if it is worth hunting down this summer??

I suspect my mechanic was right and this is way inside safety requirements.

[wolfe10]

Originally Posted by Keith55

So 32 hours ago, I pulled my rig in and shut it off.

It's down to about 50 PSI now (32 hours later) and the suspension has sagged, of course, but is still elevated.

This seems safe to me and I am wondering if it is worth hunting down this summer??

I suspect my mechanic was right and this is way inside safety requirements.

Yes, WELL within safety requirements and then some.


Do you need to "chase the leaks"-- no.



But if you have the time and inclination and a small supply of kiddie bubbles, absolutely look for those small leak(s).

[RKins]

Originally Posted by Keith55

My mechanic seemed fine with the amount of air my DP is leaking but I am not sure I am comfortable with it.

I got in today and the front was 0 while the rear was 65.

I am wondering if anyone has tackled this and where to start.

My guess is the 12 volt water "dispenser" is a good place to start looking. The valve could not be closing back up completely.

BTW, it's not at all like you shut the rig off and you can see it leak down but come back in a day or two and it has leaked down.

If you're the curious type like me:
Build some ramps so you can inspect the entire underside of the coach first hand - nice and safely too.




Then, as mentioned, slide around under the coach spraying anything with a hose, especially around the air tanks (mine are between the frame rails in front of the fuel tank) and between the shocks and the tires.

This is a Moisture ejector on the bottom of the tanks. I had 3 go bad in so many weeks. Easy to replace, slide a wrench between the tank and the ejector and they unscrew easily.


This is a ride height valve - as you can see, just inside the tires. You might have 1 or 2 in the aft also. That's the beauty of being on a creeper rolling around. This was also easy to replace. You can get both parts either from the chassis mfr or a place like Fleet Pride.

[Keith55]

Originally Posted by RKins

If you're the curious type like me:
Build some ramps so you can inspect the entire underside of the coach first hand - nice and safely too.




Then, as mentioned, slide around under the coach spraying anything with a hose, especially around the air tanks (mine are between the frame rails in front of the fuel tank) and between the shocks and the tires.

This is a Moisture ejector on the bottom of the tanks. I had 3 go bad in so many weeks. Easy to replace, slide a wrench between the tank and the ejector and they unscrew easily.


This is a ride height valve - as you can see, just inside the tires. You might have 1 or 2 in the aft also. That's the beauty of being on a creeper rolling around. This was also easy to replace. You can get both parts either from the chassis mfr or a place like Fleet Pride.

Thank so much - You clearly did a fine job! Nice ramps.

I believe my water ejectors are original so I'd bet you a silver nickel that I'd find a leak at least there.

Thanks for the picks too. Wasn't sure where the ride height valves are.

[Piros1]

Looks like Rkins has shared a few good pointers. One thing I forgot to mention is if you or your mechanic has not done this it is recommended to rebuild or replace the air dryer annually. A lot of folks don’t realize that they can come apart and create some real headaches when they do. They aren’t hard to do and highly recommend this.

Just a bit of my background is I have owned and worked on heavy trucks most of my life. Presently I own over 35 vehicles plus trailers and heavy construction equipment. The air dryer is an important part of your air brake system.