Community Forums

Jobert · 09-11-2022, 06:37 PM

You may want to check the line between the compressor on the engine and the air dryer. The leak will not show when the engine is off, only when running. Depending on the size of the leak, the air may go up to the 125 then back down and the compressor will kick back in and slowly build. When the engine is off, no air is produced so no leak. The line between the compressor and the air dryer on our coach had several extra feet coiled up and run through clamps on the frame and rubbed through. I found it by accident while crawling underneath with the engine running looking for the leak. Hard to hear with engine running, had to feel it. By the time I found it, I could barely keep enough air up to keep the E brake off and get off the road into a park. It turned out to be a stainless braided line roughly 10' long. Replaced it and all was good. Hope this may help. Happy trails Bert

Maytonr · 09-11-2022, 08:03 PM

Make sure it's water, not antifreeze. I had a new Foretravel years ago and it was always having air problems with moisture . They would repair the air problem and never look where the liquid came from. It was a leaking head gasket in a water-cooled air compressor on the engine.

bevandtomH · 09-14-2022, 07:14 PM

I’m currently at Spartan. I suspected we were losing some air in the front at Homecoming. Spartan confirmed my Air Dryer is going. I chose not to replace it at this time but will when we get to Phoenix.
The tech showed me how to check the dryer for leaking.
Using some soapy water in a spray bottle, spray the right side of the Dryer. Specifically, the horizontal cylinder shape extending from the main body.
With the coach aired up but not running is when the Dryer will show bubbles escaping.
I’ve never had water in my tanks and still don’t, but after everything else checks out, it is the only thing left.
OP mentioned he is on their second Dryer in 4 months.
Faulty parts or improper install?

757driver · 09-15-2022, 08:40 AM

Quote:

Originally Posted by bevandtomH

I’m currently at Spartan. I suspected we were losing some air in the front at Homecoming. Spartan confirmed my Air Dryer is going. I chose not to replace it at this time but will when we get to Phoenix.
The tech showed me how to check the dryer for leaking.
Using some soapy water in a spray bottle, spray the right side of the Dryer. Specifically, the horizontal cylinder shape extending from the main body.
With the coach aired up but not running is when the Dryer will show bubbles escaping.
I’ve never had water in my tanks and still don’t, but after everything else checks out, it is the only thing left.
OP mentioned he is on their second Dryer in 4 months.
Faulty parts or improper install?

Tom,

That is the regeneration valve being referred to. There is a rebuild kit for it which does not require the entire air dryer to be replaced. If Spartan or some other service center is doing the work it may be a wash with the labour added in but if one was to do it themselves it would save a lot.

bevandtomH · 09-17-2022, 07:03 AM

Hello Don, I may look into that. Thanks!
Spartan wants $600.00 for a new dryer and $200.00 for labor.
I’ll get a second opinion when we get out to Phoenix.

brobox · 09-17-2022, 08:12 AM

I did the rebuilt kit on my Travel Supreme. We have a lot of truck parts shop here in FT Myers. Walked in gave the the air dryer number and walked out with the rebuild kit around $65. back them. The Parts guy even gave me a couple of tips on the replacement parts. It was and easy 1 beer job

bevandtomH · 09-18-2022, 07:05 AM

I like one beer jobs![emoji3]
Now I will look into this further. I was told the interior body will get gummed up.
If the rebuild kit takes care of it, all the better.
Thanks!

brobox · 09-18-2022, 07:44 AM

Quote:

Originally Posted by bevandtomH

I like one beer jobs![emoji3]
Now I will look into this further. I was told the interior body will get gummed up.
If the rebuild kit takes care of it, all the better.
Thanks!

There are rubber diaphragms that age out from engine heat as well, all were easy to change. Nice part, the air dryer is right there at chair level on the 450.

DPMike · 10-06-2022, 02:25 PM

I haven't seen a message that addresses the possibility of leaking air lines or diaphragms on spring brake causing the problem. Not sure if that's possible if both primary and secondary gauges show drop in pressure similtaneously.

Haidang · 10-09-2022, 06:18 AM

After finishing travel for September and again try to find where the leaks are. I found the problem with the check valve of the new air dry. Air travel back to the compressor again. Curiously, I opened the valve and rebuilt with a new kit. Doing the test Twinboat recommended and the air dryer purged one and none in 20 minutes .There was no water in the system after the first 3 hours of driving, but I found the problem came back when I got to a campground with another 4 hours driving ( water accumulated, the air dryer purging every 3 minutes ). Opening the check valve, It was clean and dry. There was no dirt or oil attached to it. After reinstalling it, the problem was solved. The air dryer purged one and none in 20 minutes again.what made the check valve fails? What can I do to prevent It happen again? Placing another check valve between the air dryer and the wet tank is a good idea? Thanks

twinboat · 10-09-2022, 06:52 AM

Quote:

Originally Posted by Haidang

After finishing travel for September and again try to find where the leaks are. I found the problem with the check valve of the new air dry. Air travel back to the compressor again. Curiously, I opened the valve and rebuilt with a new kit. Doing the test Twinboat recommended and the air dryer purged one and none in 20 minutes .There was no water in the system after the first 3 hours of driving, but I found the problem came back when I got to a campground with another 4 hours driving ( water accumulated, the air dryer purging every 3 minutes ). Opening the check valve, It was clean and dry. There was no dirt or oil attached to it. After reinstalling it, the problem was solved. The air dryer purged one and none in 20 minutes again.what made the check valve fails? What can I do to prevent It happen again? Placing another check valve between the air dryer and the wet tank is a good idea? Thanks

Before air dryers were being installed, there were check valves right at the wet tank.
They may still have them and yours is bad.

ArtJoyce · 10-09-2022, 07:22 AM

Sounds like something is wrong with the dryer or air pluming. I had mine purging to much for several thousand miles. It was like every 2 minutes. It ended being the governor on the air pump. But I never had water in the system.

Someone else with expertise may know the answer. I was always under the impression water in the air system can cause rusting of the many valves in the entire air system. Also, it can freeze in the winter and you can get a loss of front brakes and loss of air to rear brakes which locks up the rear brakes.

Haidang · 10-09-2022, 07:40 AM

I got the air diagram of my coach from Spartans. There are no check valves between the air dryer and the wet tank and no check valves between the wet tank and the primary tank. There is a pressure control valve from the wet tank to the secondary tank that explains the only secondary system holding air when the check valve of the air dryer fails