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Topic: Another air system problem (Read 724 times) previous topic - next topic

Another air system problem

Yes, I have another problem with my air system.  If you remember, last September my coach wouldn't build up any air pressure when we first started traveling last September.  We initially replaced the D2 governor which James Triana recommended.  The fault turned out to be the Haldex drier which had an internal component failure.
Last week as we traveled from Phoenix to Las Vegas I noticed the air pressure gauges behaving strangely.  They would behave normally for many miles.  Then I would find both gauges sagging down below governor cut-in pressure and stay there for quite a while.  Then the gauges would build back to normal pressure and cycle there some time again.  What could be going on?  I'm thinking D2 governor, but why would it fail in four months?  And why would it act so strangely?
Anyway, I've bought a new D2 governor from NAPA(really new not re-manufactured like the last one, and plan to install it in the morning.  What else should I be looking at?  The leveling system is not affected, holding pressure nicely.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Another air system problem

Reply #1 –
You are probably right abut the governor I have had the rebuilds go bad with less time. Sometimes they build too high and other times they are erratic like yours.
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: Another air system problem

Reply #2 –
Brett,

It sounds like a D2 malfunction.  Since you already have a replacement in hand, swapping them out is the simplest way to verify that assumption.  If it fixes the problem, you're home free.  I'd pull the defective unit apart, and see what you find.  They are not complicated - just a sliding piston valve and some ports.  Perhaps a piece of trash or junk is blocking the action?  Clean it out, put it back together, keep it for a spare.

http://www.cumberlandtrucks.com/wp-content/uploads/2014/11/Governor-Service-Data.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: Another air system problem

Reply #3 –
How hard is it to change out the D2 govenor?
Rick & Deborah Webster
2002 3610 U320 #5964
2014 Jeep Wrangler Sahara JKU- 'Copperhead'
Richland Chambers Lake, East Texas

Re: Another air system problem

Reply #4 –
Quote from: Old Hippie –
How hard is it to change out the D2 govenor?
It depends on where the compressor is mounted. I change the one on my crane in 5 minutes. On my 1981 FT it takes 10 minutes to get the cover for the bed off. Then 5 minutes for the governor.
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: Another air system problem

Reply #5 –
Dig around and locate a pneumatic system trouble shooting (procedure) guide. 
Give Nacadoches a call, they should be able to help you.

It will give you direction more than anything else
since throwing parts at the issue is not a path to
follow.  pc
S/W Houston 95" U320C SE/40' 
Build #4778  Cummins M11
Repairs & Covered RV Parking (BAO)
PPL is close..

Re: Another air system problem

Reply #6 –
I changed the D2 governor, which had no effect.  I then crawled under and searched the brake system(since leveling was not affected).  I found a line to the rear brakes had chaffed  and worn through.  Replacing a section of hose solved the problem.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Another air system problem

Reply #7 –
Quote
  I found a line to the rear brakes had chaffed  and worn through

Any idea as to the cause of the chaffing?

Re: Another air system problem

Reply #8 –
No.  It is above the rear mudflap supplying air to one of the glad hands to my stacker.  It was at FT and Ramspeck's last month.  Could the coach have been driven with low air so the mudflap was pushed up to it?  I can't imagine highway speed airflow deflecting the mudflap that high, but I'm certainly going to monitor that line for a while.  I wish I could relocate it but I can't.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R