Skip to main content ↑ ↓
Topic: air tank leak  (Read 962 times) previous topic - next topic

air tank leak

The front air suspension has a leak. the rear airs up fine and will maintain height but the front will not.  Not sure how this system works. I did track the issue to the valve in the photo. Any assistance would be helpful. thanks

Re: air tank leak

Reply #1 –
Is that the ride height control valve. Is there a follow up arm back behind that picture attached to the valve. Should stop venting air when level is reached I carry a spare if it continues to vent once down to below ride height
Scott

Re: air tank leak

Reply #2 –
It is your leveling valve.  You will need to replace it as there is no way to rebuild it.  See https://www.finditparts.com/products/50451/arvin-meritor-s4640024430.  You can get a cheaper plastic version but I have heard a lot of mixed reviews on those.  After you replace it you will need to check your ride height on all 4 corners and adjust the rod on the leveling valve accordingly.
2002 36' U270 Foretravel

Re: air tank leak

Reply #3 –
Where do you buy a leveling valve?

Re: air tank leak

Reply #4 –
Quote from: reece1975 –
Where do you buy a leveling valve?
Amazon.com: Truck/Trailer/Bus Height Control Chassis Air Suspension Valve...
As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
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: air tank leak

Reply #5 –
It may be just an arm adjustment. You can loosen it and move it up and down to view the operation and at some middle point it will stop venting if it is still good. Aired up, key on, engine off. Or perhaps it is a fitting leaking. You were not specific.
1994 U280, Build 4490
Deming, NM.

Re: air tank leak

Reply #6 –
If you decide the valve needs to be replaced, Google for "Meritor S4640024430" and Google will present you with several purchasing options to include Meritor/Wabco and less expensive alternatives.
40ft 1997 U320

Re: air tank leak

Reply #7 –
Question,  Is the valve leaking with the HWH level system in Travel Mode, ie. Travel light ON?
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: air tank leak

Reply #8 –

If your air bags were low when your air compressor (engine) was running, it was likely your height adjuster or lines to it.  If this happens only while you were parked it would not be adjuster.  I had a problem with a front leak where I would have to run the engine (and compressor) to bring up the pressure while parked.  I traced the leak to the front air regulator that I never knew about.  It looks like an ordinary air regulator that you would find on your shop air compressor (I bought one at HD for about $13)  It looked a lot like the one in this link:

Amazon.com: AB-9051114 Air Compressor Replacement Pressure Regulator For...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: air tank leak

Reply #9 –
I have an air tank leak. Right, forward passenger side. The air leaks while parked. With engine on, the HWH will show I'm in travel mode, but the right side is still too low. I can manually air up this side then engage travel mode and all is well. This will stay aired up for the travel and for about 24 hours after parking.  Any ideas ??

Re: air tank leak

Reply #10 –
The tech beleives the ride height valve is the issue. See picture.  The front end of the coach will not stay aired up. the rear end is ok. There is a loud air leak that you can hear when the rig is running.

Re: air tank leak

Reply #11 –
reece1975,

That ride height valve looks like it is almost new.  Was it replaced recently?  The only place air should exit that valve is through the exhaust port (rubber cover) on the bottom.  If the coach is sitting at correct ride height, the rod connected directly to the valve should be perfectly horizontal.  With engine running there should be no exhaust from the valve.  In that condition, if the rod is (manually) moved down from horizontal (like in the photo), then air will be exhausted from the bottom port.

If the coach is raised up on safety stands (as it appears to be in your photos) and the engine is running, air will be continually exhausted from the valve as it attempts to lower the coach to ride height.

In other words, you can only verify the correct operation of the ride height valve with the engine running and coach at correct ride height.
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: air tank leak

Reply #12 –
What is the difference between  Meritor S4640024430. vs Haldex 90554241 Do they hook up differently?
Meritor almost 200 Haldex 55 just wandering
Chris
1999 U 320 DGFE
Build Number 5523
Chris & Elka Lang
In the field, Lonoke AR

Re: air tank leak

Reply #14 –
FYI, in an emergency you can drive the coach by removing the adjusting rod, and rotating (small movements) the ride height valve until air stops venting. If you cannot find a way to stop venting, seal air lines.

Then raise coach to approx. drive position with HWH, then drive until ride height is replaced.

Re: air tank leak

Reply #15 –
We often talk about sealing air lines, but don't often say how.  Even if you don't have special purpose plugs, you can always just double back on an air line like you would kink a water hose to stop flow.  You can then maintain the kink with a zip tie, duct tape, string, etc.
Regards,
Brett

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