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HWH air leveling

After being parked for sometime with the leveling system in the off position. I switched the auto leveling to the on position due to the rear of the coach being low. The leveling lights indicate that the rear is low. The compressor runs but the rear bags do not inflate. Eventually the system switches to excess slope mode.
Rick and Julie
Grand Villa
Build #4689
1995 4000 U280SE WTBI
8.3L 300HP Cummins

Re: HWH air leveling

Reply #1 –
If your coach is the same as my '99 the 12 volt compressor airs up the wet tank. It would take forever to get to the pressure to raise the rear of the coach. If the HWH is on a timer that is your problem. start the coach up get the tanks full and raise the rear.
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: HWH air leveling

Reply #2 –
Rick,  purchase 6-pack re-build kits from Tom McCloud on this forum, rebuild the 6-packs, especially the rear one.  Then check the fittings from the 6-pack to the rear air bags for leaks, soapy water spray.  Your coach will sit level for weeks on end, no auto level needed.

Till then, crank the engine, get the air up, level the coach and wait till rear sinks again.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: HWH air leveling

Reply #3 –
shut off the system and start over - see what happens - sometimes on my coach it seems like the HWH unit needs a "reboot" - on mine the only way I am aware to do that is shut off the 12V Salesman switch - at least that is what Derek Diverdi of MOT told me when I was having a similar issue
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)
 

Re: HWH air leveling

Reply #4 –
Quote from: craneman –
If your coach is the same as my '99 the 12 volt compressor airs up the wet tank.
When dealing with air system concerns, always dig out your air system diagram to see what's what.  It will tell you how your HWH aux compressor is plumbed.

It might be like (craneman) Chuck's coach, or it might be like my coach.  On our '93 U280, the aux compressor is connected directly to the 6-pack manifolds.  It does not try to air up the wet tank or brake tanks.

If plumbed like my coach (direct to 6-packs) then you could have a sticking or inop raise solenoid valve in the 6-pack, or you could have a leak at one of the fittings on the aux pump.

Either way, it sounds like your aux compressor output is not reaching the rear air bags.  Would require some more investigation to figure out why.

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"