Community Forums

153stars · 11-18-2022, 11:20 AM

There are protections to prevent air from air going back out of the braking system and from dumping backward out of purge valve.
So purge shouldn't leak without motor running if it's your issue.
It's said a low dip/belly in air line out of dryer before tank will be first to freeze up and should be avoided if moisture ever becomes an issue.

Parafango · 11-18-2022, 11:35 AM

Quote:

Originally Posted by dansawyer

It has been in the 20s. It is high 20s now with a high in the mid 30s.

I do not hear any air leak anywhere. The system is holding 45 lbs for 12 hours. I have not tried adding air this AM. Is there a check valve between the primary tank and the dryer? If there is I don't know how to check the dryer for leaks, they would not be possible to hear over the engine. If there is not then the fact it is holding air should rule out a major dryer leak.

I am still on the hunt for the governor.

Thank you all.

I'm in Caldwell, which is about 25 miles west of Boise. I sent you a PM with my phone number if you need to be taken somewhere for parts.
FB

Ray,IN · 11-18-2022, 01:39 PM

Some mfgrs. mount the compressed air governor on the back of the compressor. Some mount it elsewhere between compressor and air dryer. New governors are readily available at NAPA and other large auto supply stores.
This might help- top right corner of schematic:

dansawyer · 11-18-2022, 01:59 PM

Update:
I was wrong, above 80 psi there is a significant air leak in the compressor to dryer hose.

I am in a stable spot to disable the vehicle.

There is a hose shop near by.

I tried removing the hose - no joy.

I am thinking cutting the hose and using a deep socket.

Then take the three pieces to the hose shop

Thoughts? Dan

Ray,IN · 11-18-2022, 02:06 PM

Most all of those hoses are metric size fittings. There is a built-in swivel in the fitting (at least on one end) so the hose may be removed with a wrench, first the end with the swivel, then the other end.

Unplanned Tourist · 11-18-2022, 02:49 PM

Quote:

Originally Posted by dansawyer

Update:
I was wrong, above 80 psi there is a significant air leak in the compressor to dryer hose.

I am in a stable spot to disable the vehicle.

There is a hose shop near by.

I tried removing the hose - no joy.

I am thinking cutting the hose and using a deep socket.

Then take the three pieces to the hose shop

Thoughts? Dan

The compressor discharge hose has to be able to withstand high temperature. Be sure to get one like you take off. Years ago a length of copper pipe was used for the first 2 feet or so, but now it's normally a Teflon lined stainless steel hose. Just a heads up.

A good hose shop will be able to make up what you need. Just be sure to tell them it's for your compressor discharge and needs to be a high temp hose.

dansawyer · 11-18-2022, 08:03 PM

Update: With the help of a local irv2'er, without which I would have been high centered, it it fixed!! He came over, helped the diagnosis, took me to the tool store and the hose store, and stayed around until we checked it out. I am indepted to rv'ers I come across to make sure they are safely on their way. Thank you.

It was the compressor to dryer hose. We did take it to a hydrolic shop and got an exact replacement. The first test was a grand success. Everything came back on line as it should have.

Lesson learned: The pressure charactoristic had changed and i had moved it to the watch list instead of the find it list. It went from working well to not working in one step. If it part of the critical list make sure every change is tracked down. They do not always fail slowly.

twinboat · 11-18-2022, 08:58 PM

Great fix, and you didn't need a governor.

dansawyer · 11-18-2022, 09:40 PM

No. It was not the governor.

There appears to be a check valve between the primary tank and the dryer/compressor. I don't know were that check valve is.

When the pressure was under 115 or so there was no air from the leak. I did not discover it until I tried to fill the primary tank with an AC comressor. When the output from that compressor got high enough the leak showed up. This has the charactoristic that the compressor charges slowly, when it is done with the cycle the pressure drops quickly to 115 or so. But until the failure things functioned.

Once the leak got above what the compressor could handle everything stoped.

RichardE · 11-19-2022, 07:02 AM

Great outcome, and thank you for coming back and letting us know what you found. The real learning on the forums comes from knowing the solution. Many in distress don’t take the time to do as you did. Thanks again.

153stars · 11-19-2022, 07:08 AM

Glad your on the road again . The compressor has to a lot harder to make up from 80 to 120 psi good thing it kept up just enough to get you off the road.
I had to look up some ready made truck comp. discharge hoses . Was it made to order/length from roll ,a stainless braided with Teflon liner as well.I like to keep track of ways to get parts that are not just off the shelf for myself and others. Not sure who helped you for sure but "your a really good person !" and this is a good community/forum.

MN_Traveler · 11-19-2022, 08:09 AM

Good to know, and kudos to all here who helped you diagnose and fix!

dickb46 · 11-24-2022, 04:47 PM

Be sure to get many spot ties to keep that braided line from flopping around.
A couple of years ago mine somehow got stuck between the body and the frame rail.
It squashed nearly flat and eventually restricted air flow enough to make it unsafe to drive before I started looking for the problem.
Fortunately it was easy to find visually.
dick

WVPete · 11-25-2022, 06:56 AM

Quote:

Originally Posted by dansawyer

Update: With the help of a local irv2'er, without which I would have been high centered, it it fixed!! He came over, helped the diagnosis, took me to the tool store and the hose store, and stayed around until we checked it out. I am indepted to rv'ers I come across to make sure they are safely on their way. Thank you.

It was the compressor to dryer hose. We did take it to a hydrolic shop and got an exact replacement. The first test was a grand success. Everything came back on line as it should have.

Lesson learned: The pressure charactoristic had changed and i had moved it to the watch list instead of the find it list. It went from working well to not working in one step. If it part of the critical list make sure every change is tracked down. They do not always fail slowly.

I am really glad this worked out for you and that a guy was good enough to come and help. I read this thread to the end to see what the problem was. Thanks for letting us know!