Source of air leak - AF1?

[Johnontheroad]

My new to me 2015 has a rapid air leak in the rear air. It takes about 15 minutes to go from full pressure to where the Low air alarm sounds.

The prior owner used an Air Force One braking system, which my air hose (M&G) does not fit so it is now unhooked. Wondering if this may be source of the air leak? Probably not but just wanted to check before I start making service appointments, which I’m sure will be expensive...

John

[Carefree]

I don't think the leak has anything to do with you not hooking up the AF1.

On both of my coaches I had leaks in the AF1 lines on the coach side. The installer had the lines run too close to the muffler and the plastic line melted or it rubbed against the frame of the MH. It's an easy fix but sometimes difficult to detect.

Try to follow the AF1 line and listen to any hissing sounds.

[Gasman 2]

What's unhooked and where?

[Mwoodofd]

John,

With a leak that quick, you should probably be able to hear a leaking sound when you park and turn off the coach. There are many air fittings back there that could be loose, or if like mine, an air dryer replaced when serviced and the tech left off the outer seal. You can get a spray bottle with soap and water and check many of the air connections in the back. (passenger side, last door)

I would be cautious about getting under the coach unless you can lift the back driving up on home made ramps, etc. If the air bags are not deflating, then you can raise the back with the jacks, and use some jack stands for safety to check the air connections. There will be others that respond that can give you additional suggestions to look for.

[Neverhome2]

If it's leaking that much you should be able to find the leak by getting it up to full pressure (120 psi), shut down the engine and go back to the open engine bay and listen. The location of the leak will be readily apparent so you can identify what needs fixed. Good Luck!

[Gasman 2]

Originally Posted by Johnontheroad

My new to me 2015 has a rapid air leak in the rear air. It takes about 15 minutes to go from full pressure to where the Low air alarm sounds.

The prior owner used an Air Force One braking system, which my air hose (M&G) does not fit so it is now unhooked. Wondering if this may be source of the air leak? Probably not but just wanted to check before I start making service appointments, which I’m sure will be expensive...

John

John,
If you removed the air line coupler at the rear of the coach you will have a air leak every time you apply the brakes.

Sorry if this is not correct as you didn't say what was unhooked.

Richard

[Polecat47]

Originally Posted by Johnontheroad

My new to me 2015 has a rapid air leak in the rear air. It takes about 15 minutes to go from full pressure to where the Low air alarm sounds.

The prior owner used an Air Force One braking system, which my air hose (M&G) does not fit so it is now unhooked. Wondering if this may be source of the air leak? Probably not but just wanted to check before I start making service appointments, which I’m sure will be expensive...

John

For what it is worth: I have an AF1 installed on my Cornerstone. There is an air line leading from the rear axle to a check valve on the AF1. Recently, the check valve came apart and I lost air pressure. Fortunately, I was at a truck stop. The air pressure went to almost zero and would only build up to a little over 65 psi. A mechanic at the truck stop removed the air at the check valve and capped it. That stopped the air leak until I could get a new part for the AF1.

[Johnontheroad]

Gasman/Polecat and others: sorry for not responding sooner. The only thing unhooked was the line from the coach to the toad. But with my M&G system I could drive fine without the toad and never lost air pressure, but it was just a question.

Later today I will follow other advice, air up, turn off and listen for air leaks. Maybe I can at least pin down a source of the leak.

John

[Grower15]

Originally Posted by Johnontheroad

Gasman/Polecat and others: sorry for not responding sooner. The only thing unhooked was the line from the coach to the toad. But with my M&G system I could drive fine without the toad and never lost air pressure, but it was just a question.



Later today I will follow other advice, air up, turn off and listen for air leaks. Maybe I can at least pin down a source of the leak.



John

When you start your engine does the air gage marked “front” cycle, ie, increase then decrease in a short period of time? We had this problem on our new coach (2016 Anthem) after taking delivery. Entegra taps into the supplemental air system to actuate the door seal mechanisms (bathroom, bedroom and entry door). One of these lines had come loose and caused our problem. If this is the case you can either reattach or crimp it to stop the leak for a future repair. Just an idea.

[voltdoc]

Had the same issue as Polecat with my older AF1. The pressure protection valve on the older units is flying saucer shaped. Mine split open and was leaking air at a rapid rate. It was easy to hear with the engine off and easy to find.

Ironically, that valve is what prevents air loss should something go wrong with the AF1 itself.

[Polecat47]

Originally Posted by voltdoc

Had the same issue as Polecat with my older AF1. The pressure protection valve on the older units is flying saucer shaped. Mine split open and was leaking air at a rapid rate. It was easy to hear with the engine off and easy to find.



Ironically, that valve is what prevents air loss should something go wrong with the AF1 itself.

That is ironic that was exactly the same as mine.

Since I use my Air Force One, I ordered a replacement check valve. Installed it today.

You have probably already capped off the air line from the coach. That was all that was necessary on mine and would have been all that I would have done if I did not use it. Happy trails.