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Topic: 1986 GV ORED not building air pressure (Read 361 times) previous topic - next topic

1986 GV ORED not building air pressure

Usually I can start the engine and in a couple of minutes the air pressure builds up.  We needed to dump and fill today but the air pressure wouldn't build up.  Idling it about 1500 rpm got it slowly up to about 35 psi but can't get it to go any higher.  I don't hear any leaks.  Suggestions?
1986 3600 Grand Villa ORED SBI

Re: 1986 GV ORED not building air pressure

Reply #1 –
Uncle P,

First thought is the D2 governor has went kerput.
If it is building some air then the compressor is doing some work not a thrown belt

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: 1986 GV ORED not building air pressure

Reply #2 –
Check the drain valves for the air tanks to be sure they are all closed.

With engine running, hold your hand under the air dryer purge valve outlet to see if you feel any air coming out.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: 1986 GV ORED not building air pressure

Reply #3 –
Thanks!  Alas, my world is falling apart.  I read on another thread to give the D2 a "love tap".  I tried that and now when I start the engine, the throttle doesn't work it will only idle.  It was just a light tap.

I also found out the hard way that emptying into one of those portable containers is a real hassle.  One of the most unpleasant tasks I've ever done.
1986 3600 Grand Villa ORED SBI

Re: 1986 GV ORED not building air pressure

Reply #4 –
If you have an air throttle and no air pressure it will only idle.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: 1986 GV ORED not building air pressure

Reply #5 –
Quote from: craneman –
If you have an air throttle and no air pressure it will only idle.
X2.  Ours needs about 55-60 PSI before the throttle works.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: 1986 GV ORED not building air pressure

Reply #6 –
Well, duh!  I assumed the throttle was electric.  So that's not a problem.  It will build up to about 20 psi at idle and revving it at 1500 rpm will get it up to about 40 psi very slowly.

Drain valves are both closed.  No air coming out of the dryer.

I'll start looking for a D2.  None of the Napa stores around here stock them--special order only.  I'll try some truck parts places.
1986 3600 Grand Villa ORED SBI

Re: 1986 GV ORED not building air pressure

Reply #7 –
Quote from: Uncle Pa –
I'll start looking for a D2.  None of the Napa stores around here stock them--special order only.  I'll try some truck parts places.
This is shocking to me. Are you sure they understood what you were asking for? You might want to check napaonline.com, it'll tell you if they have it in stock at your local store.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: 1986 GV ORED not building air pressure

Reply #8 –
Quote from: Uncle Pa –
1.  I assumed the throttle was electric.  It will build up to about 20 psi at idle and revving it at 1500 rpm will get it up to about 40 psi very slowly.
2.  I'll start looking for a D2.
If you can only build pressure to 20-40 psi then the air throttle should not be working.  How are you "revving it at 1500 rpm"?  Perhaps you do not have an air throttle.  Look around in the engine compartment and see if you have the stuff in photo below.  If you do have those items, then you do have the Bendix air throttle and cruise control.

Where are you reading the air system pressure?  If you are just looking at the dash air pressure gauge perhaps it is reading incorrectly.  Have you checked the actual pressure in the tanks with a guage?

1.  Seems your compressor is compressing, but pressure won't build.  Still sounds to me like something is open and bleeding off pressure.  Usually when the D2 malfunctions, it sticks in one position (air compressor won't load) or the other (air compressor won't unload).  Yours seems to be somewhere in-between.  With engine running, can you feel any air coming out of the EXHAUST port on the D2?  See tech data sheet linked below:

2.  Any truck parts store should have some D2 governors in stock.

https://n0c357rmy1njbuit2friqwu.blob.core.windows.net/documents/BrddZ4M0I0EBhB_SD-01-503_US_005.pdf

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: 1986 GV ORED not building air pressure

Reply #9 –
Thanks for the replies, everyone!

I was reading napaonline and specifically searching for "Bendix D2".  When I actually went to the store, they had an "equivalent" made in China.  I don't like throwing parts at a problem but $20 isn't a big deal.  Unfortunately, one of the bolts was seized and broke off.  Looks like it could very well be the original governor.  So, after I cool off a bit (our "feels like" temperature is 103), I'll go get a new bolt and try putting the new unit on.

As for the throttle, all I know is that it didn't work for a while after starting the engine and the gauge showed < 10 psi, but after a while it started working when the pressure was about 20 psi.  Could be something else and just a coincidence.  I'm not too concerned about that right now.  But I do know for sure that I have the Bendix cruise control.

Yes, I'm reading the pressure off the dash gauge.  Since the dryer is never "blowing off" like it always does when the gauge hits 100 or so, I don't think it is getting up to full pressure.  Also, the alarm is continuous.

Obviously, I'll have to get everything back together before I can try your suggestions.
1986 3600 Grand Villa ORED SBI

Re: 1986 GV ORED not building air pressure

Reply #10 –
Quote from: Uncle Pa –
Thanks for the replies, everyone!

I was reading napaonline and specifically searching for "Bendix D2".  When I actually went to the store, they had an "equivalent" made in China.  I don't like throwing parts at a problem but $20 isn't a big deal.
I've been using the same one on my ORED with no issues all summer. I see them as disposable and keep a backup with just in case... super easy to replace as long as all your fittings are cleaned up.
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: 1986 GV ORED not building air pressure

Reply #11 –
Quote from: Uncle Pa –
Since the dryer is never "blowing off" like it always does when the gauge hits 100 or so...
100 psi is too low for compressor cut out (dryer blowing off).  Should be more like 120-130 psi.

When you get everything working right, your air system should cycle between about 90-100 (compressor cut in) and 120-130 (compressor cut out).  The D2, if it doesn't initially cycle in this range, is adjustable.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: 1986 GV ORED not building air pressure

Reply #12 –
D2 was not the problem.  I think I have almost found the air leak.  I had mainly checked around the tanks in the front and the engine in the rear and my hearing is not the best (too many rock concerts in the 70s maybe).  Also, sliding on my back underneath the RV is not easy, but that's what I did and started hearing a noise near the batteries under the steps.  Reaching up between the wall behind the batteries and whatever tank is right there, I could feel air.  I opened the steps and many of the wires had been chewed on.  I suspect mice or rats have chewed through an air hose.  I'll try to figure out a way to get to it.

Thanks again for the help.
1986 3600 Grand Villa ORED SBI
 

Re: 1986 GV ORED not building air pressure

Reply #13 –
So now you have a spare D-2! Glad you found the problem.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel