HWH

[Matteo]

hwh air leveling wont dump air

[Matteo]

Originally Posted by Matteo

hwh air leveling wont dump air

[TLGPE]

They make a lot of different models. Most dump when you turn on the control pad, but also have a separate "dump" button. Either way it sends a momentary signal to an air valve that pulses a pilot operated check valve. The valve shifts and all the air get exhausted, lowering the coach.


My experience was that a solenoid burned out on the "ride" side, and I couldn't get the coach up to the travel position. I ordered a new valve and installed it, and eventually everything was fine.


If the leveling system works OK, you can just get used to having it at ride height before you level. Otherwise check with the chassis manufacturer or HWH for a new valve ($$). You could check out the valve if you are handy at that stuff, but be VERY CAREFUL! Getting under the coach can be very dangerous.


HWH will answer your questions, but you have to leave a call-back number and let them get back to you (they will do it, but it's irritating to have to do it that way). I have a Spartan chassis, and they give good response; I think Freightliner does also.


Keep asking, somebody will have some wisdom to impart.


Tom

[azpete]

check the dump valve for mud in the vent. sometimes road grime plugs the vent hole

[MSHappyCampers]

Mine wasn't dumping at the rear. Mud daubers had filled the exhaust hole with mud!

[High Ball]

Mine only dumps on back. the front does dump. I use a different valve that the PO had installed for maybe because of problem or he wanted to dump only front to help ease going out and back in.
Would it be the valve that in the center frame on top of front steering system tha would be defective ?????
I have the Freightliner chassis and the HWH 325 series leveling system.
Any thoughts or how to diagnose this problem ???
Many thanks

[TLGPE]

CAREFULLY!
I you can use the jacks, you can elevate the front and look at that valve. It is a dual solenoid valve that shifts when it gets a 12V signal. It is detented, which mean that it stays where you shift it until it get another signal. That little valve is mounted on the larger air valve that sends a signal to the pilot operated check valves that actually dump air from the air bags. It all seems complicated, but the solenoid valve is low power (12VDC) and gets its signal directly from the HWH control board. The larger valve needs to provide enough power to force the check valve to release against the air pressure in the air bags.


You can unplug the connectors going to the solenoid and check for continuity at the solenoid coils. If one is open, there's your problem.


Be more than careful under there! You don't want anything to cause those jacks to start to drop. That could give you a bad day. Do NOT mess with the air bags, air ride, air valves, or even breathe too much air when you are sitting on the air bags; that could give you bad day.


If you find a bad solenoid, Freightliner can help with a replacement, but it may need the entire valve. Mine was $245.


In case I didn't mention it, you need to be careful under there. If you can block the frame up when you're under there, that would be safer.


HTH,


Tom

[High Ball]

TLGPE
Thanks very Tom
to unplug the plugs at either end are they just pushed in there or they are screwed. hopefully there are only two wires in plug. if not which one do I test with. do I unplug both at same time or just one at a time. It is the unit itself I test for continuity right ????

On the valve there is number V900029. does that seem to be correct
Many Thanks again

[TLGPE]

Mine are plug ins, but they have a little clip thing holding them closed. Just lift it and pull. Each cable is to a different solenoid, so you want to check both. Two wires each, use ohm meter to check for continuity on the coil itself. The connectors are different genders, so they go back only one way.


Look at the other end of the cable as it goes back towards the chassis. That is where you will find the connector that you can disconnect and test. That's how mine is; I hope that helps you.


Tom