Air problem today

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Air problem today

February 29, 2020, 09:44:46 pm

We were driving up thru Mexico today and all of a sudden the low air beeper started making a noise. Pressure was down to 70lbs at 65 mph. Slowing down and it got as low as 50lbs. I carried on for a while but decided to stop and see what is wrong. I had an old D2 governor that I had so changed it but no change. Drove on to border and a 2hour queue for border patrol. This was a night mare and at stop go it got down to 40lbs
Step even dropped going thru x-ray machine. So my question is what do the brains out there think. Coming up to Tucson at 70mph I had it up to 100lbs. Is it the D2 or a leak somewhere? We are with George and Pat Hadfield till Monday then on the road North
JohnH

Re: Air problem today

Reply #1 – February 29, 2020, 09:53:40 pm

Sounds like air leak, air dryer, parking brake chamber. Try to find a flat surface where the coach won't roll,chock the wheels build as much air as possible with the parking brake off shut the motor off and see what you can hear.

Re: Air problem today

Reply #2 – February 29, 2020, 10:21:02 pm

Let me know if I can be of help, John. I do have a aux compressor and fittings if you need to air-test without the coach running. "A good coach is one who never leaves you in a embarrassing or dangerous location." Sounds like you have one!

Re: Air problem today

Reply #3 – February 29, 2020, 10:28:27 pm

John,

Situation demands immediate attention before you try to hit the road again. At 40-50 psi you are very close to the parking brakes automatically setting themselves. You don't want to chance that happening on the highway.

Bruce mentioned some usual suspects. Also check your air tank drain valves to be sure they are closed.

Does your coach stay at ride height when you shut engine off? If it does, then air bags are OK.

Does your tow car use a air line connection to operate the braking system? If so, check there for leaks.

Re: Air problem today

Reply #4 – February 29, 2020, 11:21:39 pm

Yes stays at ride height and could not find any leaks but of course road noise and a deaf ear do not help.
I did have to hold the parking brake out while moving slow when in border line up.
Not sure it is parking brake valve as no sound of leaking there.
Will check the tank drains and other possible leak areas in morning.
Keep it coming please
JohnH
The tanks stay at 70+ while driving it is when you slow down that things happen

Re: Air problem today

Reply #5 – March 01, 2020, 12:11:12 am

Just checked air pressure 3 hours after arriving and it is the same, so leaks seen to be not happening.
JohnH

Re: Air problem today

Reply #6 – March 01, 2020, 12:18:06 am

Quote from: John Haygarth – March 01, 2020, 12:11:12 am

Just checked air pressure 3 hours after arriving and it is the same, so leaks seen to be not happening.
JohnH

pointing to parking brake release diaphragm if it leaks while driving.

Re: Air problem today

Reply #7 – March 01, 2020, 07:26:44 am

John,

Fire up and check the purge drain on the bottom of the air dryer not by listening (due to engine noise) but actually feeling to see if air is coming out. The piston could be stuck/broken dumping air. Check the steel braided compressor discharge line that goes to the air dryer to see if it is chaffed and has developed a leak. With the compressor pumping it sounds like the unloader is functioning but if you find no air dumping out of the dryer or air line leak (along with the above checks) I would go to the closest parts store and get new D2 governor and give it a try.

Mike

Re: Air problem today

Reply #8 – March 01, 2020, 08:47:55 am

Mike, I rebuilt the dryer in November and it was working fine for the first hour and half then this issue showed up. Unless I am on the road and up to speed the air is below 90 most times and if crawling along it is 50to70.
Will listen for air leaks but did not hear any yesterday but road noise and a bad ear do not help.
Air pressure on the gauges this morning are still the same as last night but the park brake is on of course
One other thing I noticed is I had to take off the desiccant tank to get at d2 yesterday and noticed that removing it there was no air pressure in unit is that correct?
John

Re: Air problem today

Reply #9 – March 01, 2020, 08:55:34 am

John
If you put the coach in "level mode" ...... ie. no ride height valves involved.... and use "high idle" will the air get high enough to reach the D2 hi set point? Will the D2 cycle?

just trying to determine if you have an air leak, bad D2 or is the air compressor on it's way out................

Re: Air problem today

Reply #10 – March 01, 2020, 09:27:14 am

Justin, the compressor was on my mind but I thought that as it gets up to 90--100 at hwy speed it may be ok but agree that at low revs it should still be pumping air.
I will do the air checks and dryer check as Mike said then see if Lives in Tucson has one to put on.
Thanks for help and any other thoughts you or others may help
It is 1800 miles to home and not a fun drive with this problem
John

Re: Air problem today

Reply #11 – March 01, 2020, 09:57:55 am

John if you can bring it up to pressure with the parking brake on, block the wheels release the parking brake, if the pressure drops with the engine off listen at the brake chambers at the rear.

Re: Air problem today

Reply #12 – March 01, 2020, 10:16:42 am

Quote from: John Haygarth – March 01, 2020, 09:27:14 am

It is 1800 miles to home and not a fun drive with this problem

It SHOULD be a fun drive, Haygarth, I once limped back to the 'green and grey' with a blown turbo and it was a 'wonder if she's going to blow' trip! Get it straight, as others have said, before heading north!

Re: Air problem today

Reply #13 – March 01, 2020, 10:30:27 am

C man, doubt it will get up to pressure but am waiting a bit till more reaso able time as it is sunday. Will do what you say and as others.
JohnH

Re: Air problem today

Reply #14 – March 01, 2020, 03:16:00 pm

Problem found. It is the main line from compresser to air dryer. Metal covered plastic line cut almost thru because this line had broken the strap hplding 8t away from the harmonic balancer flywheel and was chaffed thru.
I have taken the line out by cutting it with a disc grinder and Dave Katsuki has taken itto his home to find a fitting we can put inside the thin wall plastic pipe and then some clamps on it.
Thanks all
John

Re: Air problem today

Reply #15 – March 01, 2020, 03:30:20 pm

Sunday, of course...never fails to happen on a weekend. If you could wait until tomorrow, any good oilfield or industrial "hose shop" should be able to make up a new replacement line with little trouble. If you were here in Midland we could have it done before noon tomorrow.

Re: Air problem today

Reply #16 – March 01, 2020, 04:06:57 pm

John, been reading this hoping you would find the problem quickly. Glad you seemed to and will be safely on the road again. Where did you cross and other than the ordeal you went through with the cut air line, any problems at the border?

Other than the two hour wait?

( been there, done that ). Safe travels, and once again, great meeting up with you in Mazatlan.

Re: Air problem today

Reply #17 – March 01, 2020, 04:23:11 pm

It is fixed! John described the problem above and how he found it. Here are some pics from the repair operation in our driveway.

In the group pic: (L to R) George Hatfield, John Haygarth, Dave Katsuki, Ruth Haygarth (very happy!), Jeff Savournin, Jack Shanahan (neighbor).

George

Re: Air problem today

Reply #18 – March 01, 2020, 04:26:51 pm

BOY, that is a motley crew.

At least he had lots of supervision!

Re: Air problem today

Reply #19 – March 01, 2020, 04:44:18 pm

Glad for the result. Let's see, six tech's at an hour 30 minutes each @ $100 hr, $900. You got bye cheap.

Re: Air problem today

Reply #20 – March 01, 2020, 05:30:30 pm

Good that you found and fixed the problem. Now you should check the rear brake rotors to make sure the parking brakes did not come on and overheat the rotors, look for cracks and discoloration. Hopefully nothing bad happened. My coach will start to move with parking brakes on at 1000 rpm, and I think that is somewhat normal. If not someone will tell me that I need new parking brake cans.

Re: Air problem today

Reply #21 – March 01, 2020, 06:09:17 pm

Brakes never came on as first time it happens at 2mph I pushed and held button in
Worked
John

Re: Air problem today

Reply #22 – March 01, 2020, 06:13:46 pm

Glenn, Al is good thank goodness. No real issues except obvious and you take the airport turn off for nogalas off 15d onto 15 then turn left at Blvd L D Colisio just after pedestrian overpass and do not miss this left turn. Do NOT take the USA and Centro sign. This left is your only access for the buses and coachs to go thru customs
John

Re: Air problem today

Reply #23 – March 01, 2020, 08:07:24 pm

More pics of workers
John

Re: Air problem today

Reply #24 – March 03, 2020, 02:45:14 pm

Just an update on the old issue.
I checked the fix on that cut air line fix and as of this morning after 2days of driving it has not moved. and pressure is good so again thanks for all who gave me suggestions and I am really glad I decided to try and find problem before carrying on with the drive. I now know that we would have not got very far before it completely broke and a big loss of air.
JohnH

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