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HWH levelers


lenp

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When pulling and repairing my hot water tank earlier in the week I discovered my HWH leveling system (610) no longer functioned. the pump would not run at all when trying to raise the coach. I had been having some intermittent problems on our trip down here to Louisiana (from Oregon) but had always managed to get them to work.

 

The troubleshooting guides HWH provides were EXTREMELY helpful in identifying the "pump relay" as being the problem. Ordered a new one but also found one "close enough" for temporary repair. All is good now.

 

Now for the NEXT problem......

The owner of the campground we are staying at observed me repairing mine and asked if I would have a look at his. He has a 95 Allegro Bus with the 200 series HWH levelers.

 

Problem with his was the pump starts to run as soon as you turn on the leveling system. It is not supposed to run until you move the joystick. Troubleshooting guide from HWH isolated the problem to the "valve assembly". Closer inspection of this valve assembly reveals it is a set of eight valves (2 for each jack) and a "switch" that applies a ground to one side of the pump relay when the joystick is activated.

 

This switch is the problem. This switch is made up of a rectangular plate with a round hole in the center. The plate is isolated from ground via nylon standoffs and when the joystick is moved left, right, up or down a section of the joystick makes contact with the plate. The joystick is at ground potential (via a separate ground wire and chassis contact) and applies a ground to the "switch" plate and therefore, one side of the pump relay. Appears the problem is the plate mounting screws have been (I think) over tightened resulting in the nylon standoffs being compressed to the point the plate is making contact with one or more of the hydraulic valves below it resulting in ground being applied to the plate all the time and, thus, the motor running.

 

HWH troubleshooting instructions say to replace the valve assembly. Not sure how much that would cost but I am sure it won't be cheap! Looking at how it is built I believe we can repair the existing switch assembly by either (1) adding a small spacer under the existing nylon standoffs to clear the valves or (2) replace the nylon standoffs (if we can find them) or (3) insert some insulating material (inner tube???) between the plate and the valves. Inner tube probably would not last very long though.

 

Anyone else out there ran into this problem and have a solution? Appreciate any suggestions.

 

Lenp

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Oscarvan,

I like the idea of a hobby box but, unfortunately, the joystick not only provides the ground for the pump relay, it also mechanically activates the hydraulic valve for each of the jacks.

 

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Here is a diagram of the valve block. The bottom of the joystick (actuator ball) makes contact with one or two of the "extend plungers" AND the "contact plate" when the joystick is pushed in any direction. The contact with the "contact plate" applies ground to one side of the pump relay turning on the pump and the plunger directs hydraulic fluid to the jack(s). The "contact plate" is nothing more than a rectangular piece of sheet metal isolated from the valve body by nylon standoffs. The valve block itself has a ground wire connected directly to it, thus the joystick acts as a switch when it makes contact with the "contact plate".

 

Over time this "contact plate" has become warped due to the "actuator ball" pressing on it when the joystick is moved in any direction (heavy handed operation??). The bottom of the "contact plate" does have an insulating layer on the bottom to prevent it from shorting to the "extend plunger" hex retainers - very little clearance between the caps on plungers and the plate. Over time the warping of the plate combined with the insulating material deterioration has resulted in the ground being applied to the "contact plate" all the time, thus the pump is ON all the time when the HWH system is powered ON.

 

Essentially we have the "problem" solved but the solution is still elusive. The "contact plate" needs to be replaced or reworked. Unfortunately, the joystick assembly must be removed before the "contact plate" can be removed. We CANNOT get the joystick removed from the valve block. There is a "stem" inserted into the valve block that has a "ball" on the top. The joystick "actuator ball" and this "ball" act as a ball joint at the bottom of the joystick. The only way to get the "contact plate" off of the assembly is to remove the entire joystick assembly including the ball joint. So far we have not been able to do that. I assume the joystick, actuator ball and the shaft with the ball on the top are a sub assembly and must be removed together. Unfortunately, I (we) do not have a puller configured to do that (pull on the actuator ball and push on the valve body).

 

If anyone has ever taken one of these apart, I would certainly welcome your suggestions. Perhaps at least confirm my theory??? Expect to hear from HWH tomorrow so we MIGHT have it solved soon.

 

In the meantime, thanks to all who have responded.

 

Lenp

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SUCCESS!

 

Talked to HWH this morning and found out the stem that the actuator ball is mounted to is screwed into the valve block and has an allen head. To get to the allen you must (1) unscrew the joystick from the actuator ball and then (2) unscrew the plastic insert from the top of the actuator ball. This exposed the allen for easy removal of the stem.

 

We had removed the joystick and thought it looked like a torx head screw but had nothing to fit it. Turns out it is a 1/4 allen head and I don't think a 1/4 allen will fit through the plastic threaded piece. Might have but it did not look like an allen until the plastic insert is removed.

 

We had tried to remove the plastic insert earlier but were afraid of breaking something as it appeared to be pressed in versus threaded.

 

Now we have it all apart and new part is on order along with replacement plungers - might as well rebuild the whole thing while it is out of the coach.

 

Hope this adventure helps someone else down the road!

 

Lenp

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Good work...... Tricky little engineers! At least you were able to find someone that had the info and was willing to share.

 

If you hadn't been able to get the joy stick off my suggestion would have been to maybe cut the contact plate into two pieces, and refab it in two pieces, grounding both sides.....

 

But this is much better.

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HWH was great in their support. Kudos to them!

 

Parts should be here in a couple of days and we will get it back together. Only bad part is Jim (the owner) broke a couple of the hydraulic hoses when he removed the unit. Hoses were VERY brittle so he is planning to replace them all.

 

Lenp

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Only bad part is Jim (the owner) broke a couple of the hydraulic hoses when he removed the unit. Hoses were VERY brittle so he is planning to replace them all.

 

Lenp

Thanks for this input. For some reason (brain out to lunch maybe) I would not have thought about the lines getting brittle. But,after 20 years I can see where that would happen. I wonder how many others rigs are coasting down the road with brittle lines?

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