Community Forums

bluegrasser · 06-04-2011, 05:19 PM

My HWH jacks act much differently with temperature changes. If the coach has been parked overnite and the temperature is in the 60's, or less, the jacks retract swiftly, the fronts in less than 30 seconds and the rears about 90 seconds. However if the weather is warmer the retraction times are much longer and sometimes need a pry to get them started back up.
If the coach has been driven the rear jacks go down just fine but the right front chatters and seems to bump when being extended. If I try to retract them to reposition the coach on a site, all of them need prying to get them to go up. I have replaced all 8 of the springs with the newer style and replaced one failed selenoid valve. The fluid level is right where it should be. I have been working my way through jack troubles since we bought this "new to us" 2004 coach a year and a half ago. Could this be a fluid problem? Can the jack cylinders and rams change size so much with temperature changes that binding occurs? I know it's hot under there after a drive, but I would think they should be able to handle that.
The rams are clean and have been wiped with a little ATF on a clean rag.
I have cleaned out the area at the bottom of the cylinder with a "Q tip".

I need help with this annoying problem.

Thanks

GaryKD · 06-04-2011, 05:29 PM

Hi bluegrasser,
You are correct, temperature plays a role in HWH jack operation. However, usually it is the opposite of the information you provided. Gut feel says the large seal at the bottom of each cylinder has begun to collapse around the piston. This can cause quite a few different problems. Many of these were mentioned by you. The only cure is to replace the jacks or have them rebuilt.

I have replaced 2 of my jacks because of the seal collapsing problem.

bluegrasser · 06-04-2011, 07:46 PM

Hi GaryKD: Thanks for your quick response, my own 'gut feeling' was leaning the same way as yours. I guess I was hoping for a simple cheap fix, but that never seems to be the way with motorhomes. Two more questions, although I don't have much faith in "mechanic in a can" fixes, are there any seal conditioners available that might help restore the seals? If it comes down to rebuilding or replacing the jacks, is there a significant cost difference. Oops a third question, can a competent hydraulic repair shop rebuid these units or do they need to go to HWH. We live in a rural area and the farmers have hydraulics all over their equipment so I should be able to find a repair guy.

Thanks

Mr_D · 06-04-2011, 11:23 PM

HWH doesn't recommend wiping or spraying the rams with anything.

Seems to me I remember reading that the rams are welded and must be cut apart and rewelded but I've never had a problem with any of the three HWH systems I've owned.

SeattlePirat · 06-06-2011, 11:46 AM

You are very very lucky. We have had our motorhome for 7 years and its always the HWH giving us grieff.

scenic route · 06-06-2011, 09:58 PM

Wiping the jack struts with a clean cloth and the same fluid they operate with is a GOOD thing...a clean strut is a happy strut.

Bob

Mr_D · 06-06-2011, 11:56 PM

Quote:

Originally Posted by scenic route

Wiping the jack struts with a clean cloth and the same fluid they operate with is a GOOD thing...a clean strut is a happy strut.

Bob

Not according to HWH support when I talked to them about this very subject.
I've NEVER cleaned the rams on any of my HWH systems even though I've had the rams fully extended on the front for about 7 months straight every year for the last 8 years.

Mr_D · 06-07-2011, 12:09 AM

Quote:

Originally Posted by SeattlePirat

You are very very lucky. We have had our motorhome for 7 years and its always the HWH giving us grieff.

A lot of that depends on the factory installation. What MH do you have?

Our rams are the 12,000# models and there are four of them so none of them is close to maximum. Front axle weighs 13,200, rear is about 19,100. Yes, I can and do lift the front axle off the ground if necessary to level, NEVER the rear though! Did that ONCE with our first DSDP. It went sideways almost into a telephone pole. I thought I'd bent the frame till I realized the jacks were on a pivot!

trainsktg · 06-07-2011, 07:22 AM

If you lift the rear wheels off the ground, you've also lost your brakes.

HWH may recommend not wiping the rams, but mine did stick (as in not move without prying) until I started wiping them periodically. In my case, I use a spray silicon.

Bluegrass, my jacks work identical to yours. The speed of retraction is significantly faster in cold weather, and they slow way down the warmer it gets.

Keith

bluegrasser · 06-07-2011, 03:05 PM

Trainsktg: I'm glad to hear that someone else has slow or stuck jacks when the temperature rises, and that you have found a solution. I will spray the rams with WD40 and then wipe them down to clean off anything that may be on them, then apply a silicone spray. I just priced replacement jacks at $480 each. That may be the "welcome to Canada" pricing, but I think I can do a lot of experimenting for $480. Tomorrow is predicted to be in the 30 degree celcius range, so that will be a good test.

P.S. I do carry a big pry bar with me so I can get them started, but it's a bit embarrasing to be out there in the middle of big fancy rigs, prying up my jacks with a crow bar.

codgerbill · 06-07-2011, 03:36 PM

For what it is worth,

I had a hydraulic cylinder replaced at the HWH facility in Elkhart Indiana. The right front jack was (and is) slow to retract but it retracts whithin what the tech at the HWH facility said was within a specified time frame. I asked about using silicone spray and he said it was ok but he also recomended using WD40 and then wiping the jack off. He also said WD40 is vegetable oil

. I dunno if I believe that but I have used the silicone spray. The tech also recomended extending and retracting the jacks on a peridioc basis (when the coach is in storage) to keep the seals lubricated.

Peterd503 · 06-07-2011, 03:51 PM

All four of my jacks were starting to leak. The local machine and hydraulic shop resealed them all and machined new pieces for the front ones for less then the cost of new seals for one jack from the manufacturer. They charged me $75 and I did the R&R.

SeattlePirat · 06-08-2011, 08:50 AM

Quote:

Originally Posted by Mr_D

A lot of that depends on the factory installation. What MH do you have?

Our rams are the 12,000# models and there are four of them so none of them is close to maximum. Front axle weighs 13,200, rear is about 19,100. Yes, I can and do lift the front axle off the ground if necessary to level, NEVER the rear though! Did that ONCE with our first DSDP. It went sideways almost into a telephone pole. I thought I'd bent the frame till I realized the jacks were on a pivot!

Mr D, we have HWH AP9517 on the front,,we have lifted ours off the ground too. And it would seem that is the one, front, giving us the most grief. Finally out of frustration, two days ago, I sprayed copious amounts of a spray called RV Spray that I got at Camperworld. I stored the jacks and they all came up nicely. I then put the jacks down again and sprayed againl, lots of it. The jacks stored properly again in 5 minutes. The coach is in a shop now and when it comes home, I am putting the jacks down again and do it all over.

It is my intention to buy new springs and install on the front of the coach and see how that goes.

We have a 2004 Kountry Star made by Newmar. This is the wifes RV as she uses it to go to dog events. The jacks are nuisance to me, but a major crises for her. If the situation isnt changed soon IM going to consider other alternatives. It spoils her weekends.

Chuck 1935 · 06-08-2011, 12:43 PM

My HWH jacks also retract slowly. My solution is to start the MH, hit the store button and give them enough time to clear the ground by about 5 inches and off I go. Of course I only do this if the ground and roads are level so there is no chance of hooking a jack. By the time I am ready to exit the Park they are all stored and the lights are out.