air leak Air Leak

[Joan Catlett]

I own a 2001 Monaco Sig General. In walking to the rear of my coach on the driver's side, I can hear air escaping near the drive axle.  Any ideas on what I should look for and how to resolve the problem?  I know this problem has been discussed before; however,  I am unable to find the discussion on this new forum. Your help will be greatly appreciated.

[Dennis H]

Spray bottle with soap. If you can't find soap available, Dolllar Tree has bottles of kids bubbles. Works better than reg soap too. The rear of your coach has many many air lines and it could be a leak from any one of them.  In the middle, in front of the rear axle you can see a manifold with many air lines attached.  aA word of CAUTION, do not go climbing/sliding around under your coach unless it's properly blocked. Especially with a known leak. Be safe....Dennis

[Wayne Baker]

Executive45 gives good advise.  Spray bottle with a little dish soap works good for me. Be safe.

[OhReally]

Joan, need more information. If you are parked with engine off, the leaking air you hear could simply be the air leveling system. This would be normal.

-jamie

[dl_racing427]

11 hours ago, Executive45 said:

Spray bottle with soap. If you can't find soap available, Dolllar Tree has bottles of kids bubbles. Works better than reg soap too. The rear of your coach has many many air lines and it could be a leak from any one of them.  In the middle, in front of the rear axle you can see a manifold with many air lines attached.  aA word of CAUTION, do not go climbing/sliding around under your coach unless it's properly blocked. Especially with a known leak. Be safe....Dennis

That is so true.  A sudden air loss will drop the coach to within about 4" of the ground in a second or two.  I suspect your head is considerably larger than 4" diameter.

The same applies if you have hydraulic jacks.

ALWAYS use solid, mechanical means, rated to carry the load, (ie: Jackstands) before getting under your coach.

[ken.knutson100]

Is it possible to add UV juice to the system to then use a black light to see where it’s leaking like they use in AC repair? Sometimes the air leaks are hard to find or there is so much tubing it’s hard to know where to start? I found a leak in my AC system on my truck by using the uv liquid and a black light and yellow glasses 

[Ray Davis]

 That's approx. where my air dryer is located . That is what you hear on semis when you hear a big air discharge .

 Your coach will do the same thing periodically when the engine is running .  Could that be what you hear .

 Of course it can develop air leaks as well .  

[Highwayman]

There are 4 main areas that leak. The leveling valve, the air dryer ( check at the base ), the brake control valve that is attached to the chassis and the maxi brake ( only when the brakes are released ).  Some coaches have a air pressure sensor connected to the rear air tank, they are half metal and half plastic. The plastic gets brittle and it will leak. 

All these are easy fixes .

[cureinc1]

We just had our coach air leaks fixed.  There was a leak at  the onboard compressor, one at the ride height valve and the most significant  was at an air box that goes to the turbo actuator.   You could hear the  air leak.  The air box had to be replaced $1,000 for the air box.  From what I have gathered this is a common problem. 
 

Ernest Cuaron 

06 Signature 15 SRX  Cadillac 
505-615-0675

[Jobert]

On our 06, I have needed to replace a couple of the swivel T's.  there are several of these front and back and it seems the o-ring in the swivel T part must dry out over the years, Just another place to check.  Hope this may help. Happy Trails  HH

[CountryB]

On 3/27/2020 at 9:24 AM, ken.knutson100 said:

Is it possible to add UV juice to the system to then use a black light to see where it’s leaking like they use in AC repair? Sometimes the air leaks are hard to find or there is so much tubing it’s hard to know where to start? I found a leak in my AC system on my truck by using the uv liquid and a black light and yellow glasses 

That didn't work - tried it.  I have a thread on this subject on another forum.

Could be that the air pressure is too low to move the AC leak-detecting fluid through the entire system (I assume it is just sitting at the bottom of the wet air tank, or coated the tank). Maybe I didn't use/add enough (I added 8 oz. which is a full bottle of UV leak-dye).

Maybe over time some of the UV fluid will work its way through the system and show at the source of a leak, but if it did make it through the air system it should be visible at the "exhaust port" of the air brake and leveling valves by now - which is the path of least resistance (compared to a small air leak at a fitting or such).

Edited April 7, 2020 by CountryB