[jorma]

New Newell owner, so these might be stupid quesions.  What is an HPV valve?  What is a "6 pack".  All of a sudden my coach won't get past 90 lbs. and drops to 70 lbs. after a bit.  Needless to say the bags don't inflate.  I had a semi truck repair guru tell me he thoght I have a blown air bag, does that sound reasonable?  I replaced the governer and unloader valves in my compressor thinking it might be the compressor.....any ideas what to check next?
Mike M.
#373

[encantotom]

hi mike,

check your email. i sent you my contact info

tom

[77newell]

There is a quick test to tell if it's a blown air bag or is something else. When starting the engine, immediately put the HWH leveling system in manual mode. This isolates all the air bags via the valves at the various 6 packs. If pressure builds normally with this setting of the HWH leveling system, but drops and stays down as you have described when you change the HWH to the travel mode, then you most likely have a leaky air bag. If the pressure continues to behave as you described, even in the manual level mode, then the problem is not an air bag (actually you could have a leaky bag but have a much larger leak elsewhere).

HPV is not a term I'm familiar with, but HCV (height control valve) is very familier. An HCV adds and subtracts air to the air bags while in the "travel" mode on the HWH panel to keep the height of the coach constant above the road surface as you move down the road. There are 1-2 of these valves on each axle, with the valve mounted to the chassis and a rod from the valve attached to the axle. Many 90's coaches had HCV's with plastic bodies that have been know to cracked and leak a lot of air which you can usually, but not always, hear by listening at the wheel wells.

[Fulltiming]

The Six Pack is the group of six solenoid that are used by the HWH leveling system to adjust the air pressure in the bags when leveling. There is one in the front behind the headlights, on the drivers side and one or two sets depending on the year of coach (likely just one set on yours) in the engine compartment on the passengers side up close to where the firewall would be. They are an aluminum block with air passages inside, six solenoids, each  about the size of a 35mm film case. There are two travel solenoids, two raise solenoids and two lower solenoids. During the early 1990's there were two sets of six packs in the rear. One set for the drive axle and one set for the tag axle.
   

[Richard]

Mike,

You want to study HWH publication ml20635. I would post a link, but I am not smart enough to know how on this blasted iPad. Links are listed in several threads about the leveling system, and you can also just put that into google and go to the HWH site. It will really help in understanding the basics of your system.

The super super key point to take away from this diagrams is that the air supply for the HCV goes directly to the HCV and the output of the HCV travels through the six pack to the air bags. The air supply for UP leveling goes to the six pack and is separate from the air supply to the HCV.

Maybe some kind guru will post the link for you

[Fulltiming]

https://www.hwhcorp.com/ml20635.pdf