HWH jacks not extending but pump runs

[J&JD]

Pulled into an almost level concrete spot yesterday and decided to auto level with jacks. Hit auto hydraulic, bags deflated and pump turned on. Screen changed to “excess slope” and system stopped almost immediately. Reset system and tried “manual hydraulic “. The pump turned on but the jacks would not extend. Reset system and tried “auto air level” (my coach has the HWH Active Air installed) and the coach leveled with AA (no jacks). The HWH full room slide extended just fine using the same pump.
Why would the hydraulic jacks not extend no matter whether I tried auto or manual level. As I said, the pad I’m on is very close to level and the hydraulic pump runs.

 

[Scotttkd2]

I had my local tech out last week and we had some leveling jack issues while he was here, took several on/off cycles of the ignition key to get the system to go through a complete level cycle. He thinks it might be low hydraulic fluid, haven't checked it out yet as we are stationary for a few more months but is on his list to come back and look at. Couldn't hurt to look. In my instance we started the level sequence, and it would do nothing for several minutes then suddenly the jacks would begin moving. Off ignition, wait a minute on ignition, try again and eventually it took.

 

[J&JD]

I had my local tech out last week and we had some leveling jack issues while he was here, took several on/off cycles of the ignition key to get the system to go through a complete level cycle. He thinks it might be low hydraulic fluid, haven't checked it out yet as we are stationary for a few more months but is on his list to come back and look at. Couldn't hurt to look. In my instance we started the level sequence, and it would do nothing for several minutes then suddenly the jacks would begin moving. Off ignition, wait a minute on ignition, try again and eventually it took.

Thanks @Scotttkd2, I did check the fluid level & that’s ok. Cycled the salesman switch but haven’t tried cycling the ignition several times. Also haven’t turned chassis power on/off. Those are my next steps. Just finished a 6k trip with all systems working fine.

 

[MemoriesByTheMile]

As @Scotttkd2 mentioned, cycling the power, so all lights located on the control board turn off, has addressed some issues for us in the past.
For our coach, this requires turning off power to the chassis. But I don’t know how your coach is wired.
If it was just 1 jack not working, I would suspect a valve was sticking, but since it sounds like none of the jacks moved, then I would suspect that the control board is not triggering any valve to work. Hoping a reboot will solve it for you.

 

[team bradfield]

I had similar issue, did the same as @Scotttkd2, solved issue

 

[SteveMA]

Similar issue last year - would error with slope warning within 10 seconds and no jack piston movement. Likely cause - 3000 PSI pressure switch on the ORANGE wire at the pump. Pressure switch is supposed to ground the orange wire when hydraulic pressure exceeds 3000 psi. Called HWH with issue, they said - "disconnect the orange wire from the ~3" long brass switch and if the pump cycles normally with jack deployment the switch has failed..." Mine worked fine with orange wire disconnected. Ordered new 3000 pressure switch and changed out - takes about 30 min. Don't recommend leaving it unconnected but you can get around the issue.

Arizona Pete is an HWH service tech who is spectacular. he normally monitors a lot of the forums.

 

[DavidL]

one little detail, ensure you don't unscrew the high pressure sensor when there is weight on the jack in question....bad day would ensue.

 

[SteveMA]

Correct!!! You DO NOT unscrew the 3000# sensor/switch to test. ONLY unplug the orange wire (it has a connector in line about 8 inches from the 3000# switch) to test if the pressure switch has failed.

You have to speak to HWH about your particular coach as to CORRECT procedure to change the 3000 pound pressure switch. While the job is relatively easy, you have to follow their instructions.

 

[DavidL]

On little detail further, best is to not have any pressure (spring or certainly not coach weight) in either direction (up or down) to minimize fluid loss and danger. Put a paper towel on the top of the cylinder when unscrewing the bad sensor to catch fluid leakage (there will be some, no matter what you do).

 

[Chuggs]

There is also a 50 psi switch on ours. The 50 psi switch closes a signal to ground when 50 psi is reached. It must signal at least 50 psi for valves to open during extension. If your pumps run...but none of the jacks extend...I would start with testing the 50 psi switch. The 3000 psi switch is for excessive slope.

 

[J&JD]

There is also a 50 psi switch on ours. The 50 psi switch closes a signal to ground when 50 psi is reached. It must signal at least 50 psi for valves to open during extension. If your pumps run...but none of the jacks extend...I would start with testing the 50 psi switch. The 3000 psi switch is for excessive slope.

@Chuggs , I did get an immediate “excess slope” warning on the screen as mentioned in the OP. That is why the the 3000psi switch is in consideration. So, which psi switch is the most likely culprit if it is one of the two?

 

[Chuggs]

Opps deleted my post somehow. I was trying to say...

I believe if the 50 psi switch is inop and doesn't allow the port to open...the jacks won't move, the motor keeps turning, and the psi reaches 3000 psi quickly with no place to go, and excessive slope is triggered as it is supposed to with 3000 psi switch being triggered. Normally, the jacks would stop moving when they ahieve 220 psi and have leveled the coach...motor will stop before reaching 3000 psi.

A follow up thought...

If you short the 50 psi to grounding point the valves should work and the jacks move... if they don't move...the shuttle valve in the unit may be seized...stuck in the position that lets the fluid retun to the reservoir. Just a second thought.

 

[SteveMA]

All good thoughts. Do call HWH today and leave a message - they will call back although it may be a few days. if you can find AZPete he can guide as well. Again my issue was the 3000# switch and just unplugging the orange wire was all it took to determine that the 3000# sw was bad (shorted from the orange wire to the brass case)
IRV2 has a great Newmar section and there are lots of good people there to help. Pete tends to monitor that site.

"Contact Paul at AZPETE on the Irv2 forum. He works for HWH and can answer your questions. His email is [email protected] and his phone number is 602-549-3638. He is a Commercial Member and has posted that his phone is always on, and if not answered, leave a message."

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[Chuggs]

NEWMAR COACH SPECIFIC INFORMATION – HWH® Corporation

server51.hwhcorp.com

If you go to this page...choose your coach line...then year and model...they list replacement parts and a diagnostic interactive... Might be a good reference for troubleshooting the issue.

 

[Buster]

NEWMAR COACH SPECIFIC INFORMATION – HWH® Corporation

server51.hwhcorp.com

If you go to this page...choose your coach line...then year and model...they list replacement parts and a diagnostic interactive... Might be a good reference for troubleshooting the issue.

That sure is a wealth of information. I had a few HWH documents, but this web site sure helps with the troubleshooting process. Thanks for the link.