Community Forums

michaelpatri · 01-17-2016, 08:45 AM

Tried to lower my jacks, I can hear the pump running, but it seems to be 'cavitating'....oil level is O K, jacks won't go down. Any ideas where I should look???

Skip426 · 01-17-2016, 08:55 AM

Do you have the users manual for your jack system ?

There is a trouble shooting guide ; in the manual ; and depending on the system and year there is a valve in the system that can be removed and cleaned or replaced, that valve will by-pass pressure back to the tank, if faulty.

Manuals are available as pdf's from the HWH web site.

Welcome to HWH Corporation

Algoma · 01-17-2016, 09:33 AM

Sounds as if your pump is running but the solenoids are not opening. There are several fuses around the pump that you could check. But as Skip426 advises, you should first download the documentation specific to your model from HWH to find where these are. On my previous coach the pump was powered from the chassis battery but the solenoids were powered from the house battery. I had the same symptoms as you have if I forgot to turn the house batteries on.

michaelpatri · 01-17-2016, 12:34 PM

Thank you for the link. Apparently, according to the troubleshooting guide for my series 325 jacks, either the shuttle valve or the motor needs to be replaced. I don't have the equipment to check hydraulic pressure; so a visit to a tech is apparently in order. Thanks, again for the replies.

azpete · 01-26-2016, 09:27 AM

michael. first check your fluid. then if that is ok, crack the fitting on either end of the u tube located on top of the manifold. not far, just slightly loose.if you have a good amount of fluid there, its either the shuttle valve or the hydraulic solenoids not opening. check the fuses for the jacks. the location of each is in the service manual. the motor is not the problem, as you could hear it run. if you want, you can call me at 602-549-3638
i can help
note: i do work for hwh and live in arizona.
i do not sell parts, or solicit service work on this forum

BrentN · 01-03-2019, 09:57 AM

As an update to a problem I had on my 310/325 HWH System:
The pump motor stopped working a few years back. All of the checks showed power was getting to the motor but would not run. Corrosion in the ground circuit can cause this problem by not allowing the motor to ground to the frame.

Followed the available instructions for adding a ground cable to the motor endcap (brush plate endcap) by drilling through the Negative Brush holder and adding a 5/16" bolt through to act as a stud.

The motor worked instantly, however it sounded like it loaded up for a second or two and the sounded like it was spinning freely. The jacks would not extend, nor was any hydraulic pressure available at the pressure check port.

Another poster suggested checking the motor to see if it was running backwards. Alas it was. During the modification for the ground stud, the motor endcap got clocked 180 degrees out of phase during reassmbly with the motor shell. This will cause the motor to run backwards. The endcap can be in one of two clocking orientations with the motor shell, and it matters as it will change the direction of the rotation of the motor.

The motor endcap and motor shell are marked, but when you add 20 years of dirt and oil, the marks cant be seen. Always mark the endcap to shell prior to pulling the bolts all the way out.

The pump is now running the correct direction and the jacks are working. Its an easy repair. Had I used a similar size bolt for the ground stud as the Positive stud, I also could have just swapped the two cables and the motor would have been rotating correctly. Hope you find this useful.