Do it yourself service repair on HWH leveling jacks

My HWH jacks have been getting slower and slower. Finally yesterday I decided to find out just how slow.  The MH has been sitting on the pad for about a week with the jacks extended.  I got out the stopwatch and hit the store button.  The weather was a comfortable 68 degrees, and the pad level.  The front jacks retracted in about 2 1/2 minutes.  The passenger rear came to a near stop at about 1 inch to go.  At 24 1/2 minutes the passenger rear alarm finally shut off.  The driver side rear stopped about 1 1/2 inches out, and after waiting 30 minutes, I finally shut of the pad and levered it up the last inch or so.  Well, I gotta try something, I don't have much to lose at that point. 

I extended the rear jacks as far out as they would go, and crawled under with a creeper, mirror, and a can of spray silicone. Using the mirror I could see that a significant amount of gunk was packed in around the seal. As a matter of fact I could see no seal, just debris.  I sprayed the silicone all around the seal with a plastic straw tip so I could get right up next to the seal.  I coated the seal and waited for about a minute. Then I sprayed again and using a small tip flat blade screwdriver with a cotton rag covering the blade, began going around and around inside the lip of the jack against the seal (gently).  Tons of muck came out, some like mud, some bits of debris, and even sand particles. After cleaning both rear jacks squeaky clean, I re-silicon ed the seals and jacks and wiped off the excess with a clean cloth.  The seal of the jack is about a half inch up inside the sleeve of the jack.  Lots of room for gunk to collect. 

I went back inside and hit the store button with the stopwatch to check times.  Unbelievably the Driver side jack that wouldn't retract in 30 minutes, now was completely seated in a minute and 23 seconds!  The passenger side jack stored in a minute and 31 seconds. 

After such great results I did the front jacks while I was down there.  As a note, they were nowhere as gunked up as the rears were.  After cleaning and applying silicone to the fronts, they stored in 40 to 45 seconds. 

I included a few pics of the seals looking up into the jack sleeves with my camera phone.  You have to blow them up to see detail better.  The shiny gray ring around the stainless ram is the seal. Then you can just make out a steel rim outside of that the inner seal sits on.  Between the steel rim and the seal was where the majority of the gunk was built up.  The pics aren't great, but the camera phone is just so good. 

I often wondered why HWH wouldn't suggest checking that area for build up.  Maybe they are afraid someone would damage the seal or the jack tube if they got carried away.  Being that I am out of warranty and any repair is on me, I had nothing to lose giving it a try.  I don't know how long it will last but it's pretty cheap maintenance rather than buy a couple of new jacks. 

If you are having a jack retraction problem, try giving the jack tube seal a good cleaning, it may save you some serious money. 

Sarge

I've always been told to clean the shiny part of the piston with ATF - I always look at mine before retracting if we are in an other-than-normal situation, and clean the piston before retracting. Seems to work for me.

Sounds like you found the solution to a problem that has been mentioned here many times, Thanks!


BTW: I don't want to start another Si discussion but you might consider using a solvent/cleaner that contains petroleum products to be more compatible with the "high" pressure seals.  Just my $0.02.

Sarge,

Thank you very much for posting this info!!!

Right now as we speak, I'm having some Hydraulic HWH jacks installed on my 2006 Tioga Class C...I'm looking forward to some level times ahead! Not to mention an RV that doesn't wiggle and move as much when people are walking/moving around.

I'll be extra sure to keep an eye on the jacks and make sure they stay clean. We do a fair amount of ATV riding so we'll be trekking some miles through the dirt to get to various camp sites...a sure way to rapidly accumulate a lot of dirt/dust/debris.

QUESTION....on my Honda 400EX quad, I put some shock covers over the shocks just to help keep them clean. I'm sure you've seen 'em; plastic/rubber boots that look a bit like an accordian. I'm sure you know where I'm going with this: would such boots/sleeves be an idea for the HWH jacks???? Seems like a great way to protect and keep them clean, provided they'll fit. In my case the jacks are swing-down, so it might be a bit more involved with with having boot-covers on while stored upright....but in the case of a Class-A, you'd think it's a great idea. Eh???

The boots could actually be a great idea, but wouldn't work in my application.  I have about 8" square feet on the bottom of my jacks that would prevent sliding them on.  Obviously boots would help a lot, my Blue Ox tow bar has them on for just that purpose, and many after market shocks for my Jeep come with them included. 

I used silicone due to a suggestion made to a member here recently who called and spoke to a HWH tech.  He recommended cleaning the jack tube with WD-40, wiping it off and spraying it with silicone, and wiping off the excess.  I will report back later after I have had some time to evaluate the retraction rates on the jacks after some use.   

I am having problems with my 99 Coachmen Sportscoach DP jacks failing to return to the stowed position.  I tried the various fix-it remedies but the problem always came back within a few months.  They have been slowly getting worse over the last ten years.  I've been using a 2 x 4 on a couple of them but now they are really fighting me.  Time to do something.

I pulled all four off, the fronts are 9,000 lb model AP9551 and the rears 12,000 lb model AP9552, both straight acting, 7 degree pivot, spring return.  I see a lot of gunk built up in the seal area where you are talking about.

I called HWH and got some new gal that kept asking her "supervisor" the questions.  She quoted me $260.82 for each front and $293.92 for each rear. Total $1,109.48.  After I lifted my jaw off the floor I told her I could not pay that and will be doing something else instead.

Just wondering if you can give me an update on your repair.  Are they still working good?  It's a pain in the backside to remove and replace them so I am hoping to do a one-time fix.  I have my own shop and have rebuild just about everything in my lifetime so rebuilding these would not be a problem if I can get new seals.  Even if I have to cut the weld off the top to extract the piston and re-weld it again.

Any help would be appreciated.
Rick

If it is the seals that are shot, replacement may be your only coarse of action.  However, if really slow retraction is the problem, it may be that the springs are just worn out.  You may be able to replace the springs much easier than you can replace the seals.

ricknsharon said:

Just wondering if you can give me an update on your repair.  Are they still working good?  It's a pain in the backside to remove and replace them so I am hoping to do a one-time fix.  I have my own shop and have rebuild just about everything in my lifetime so rebuilding these would not be a problem if I can get new seals.  Even if I have to cut the weld off the top to extract the piston and re-weld it again.

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If you are in an area of farming, there should be alocal eauipment repair facility that does repair of hydraulic systems.  The same should also be true in most cities as thereis much equipment there that need servicing too.  Check a around and see if there is a shop that can do the work for a  reasonable price  or better yet would tell you how.  There is usually an easy way to replace the seals you just need to know the trick.   

Rick, I can?t say for sure on yours but I have heard from a few that say they spoke with HWH and how the cyls are welded. However, when they remove the cyl they usually find they are repairable. Welded cyls are usually ?throw-away? in the HE industry so if you do run into a set of these the seals will probably not be readily available (except to HWH). You can usually mic the piston and order them though. Nothing is throw away if you have the time.
If you did have an internal seal bypassing on a single acting cylinder it cannot do it for long without leaking past the wiper seal. This is the seal at the bottom that you can see. It is there mainly for dirt, etc and will not stand high pressure like a piston seal so that means you get oil on your rod. If it is not leaking then the biggest problem is the seal actually looses it?s pliability from age, temperature & dirt and the rod actually starts dragging through this seal and taking longer to extend/retract as Sarge & others have said above.
I also have run into quite a few that would not retract without a 2x4 helping and the repair has always been the same in my case. Lower the jacks until they touch the ground, start with one and as it is retracting soak it with silicone spray near the top of the ram going up into the seal as Sarge did. When it stops retracting or starts going real slow then reverse direction and lower again. Start retracting and spraying again like the first time. Sometimes I have had to do this 4-5 times on one cylinder but they always start working pretty close to normal right away where the spring retracts the jack as it should etc. I do this once in the spring and once when I put the rig away for winter and have not had any other problems. The silicone is light enough to get up in around the seal. There is nothing wrong with using other types of light oil but then you have to clean and dry the rams etc or you are going to attract dirt right back in and start the process over again. I wouldn?t worry much about compatibility, they are using everything from nitrile to viton depending on where you look and we could probably never wear one out from incompatibility issues. Besides, silicone is cheap and easy to use IMO. I would certainly do this before I started tearing things apart, that costs money! You have other testing options because you have removed the jacks but don?t know if you want to go through that. Hope this helps and let us know what you end up with.

Thanks for all the replies.  They are not leaking at all, just will not return without some help.  Two of them are getting extremely hard to pry back to stowed position.  I use to be able to pry them up using a six foot 2 x 4 and a series of various sized blocks as a pivot, gives me about 10:1 ratio.  Now I can put all my weight on it and they barely move, so that's like 2,000+ lbs of force.  I don't think new springs are going to help.

I don't believe this style uses a conventional piston with seals and a rod wiper, I think the 2.0" (front) and 2.375" (rear) diameter rod acts as the piston.  The seal at the end is the only seal/packing.  The rod must have some kind of a stop on it to prevent it from pushing completely out.  That's what makes me think the top end is welded together after the rod is inserted.

I've tried silicone, various oils.  I can't say it helped.  Maybe a little improvement but short lived.

Question for SargeW. 
On your first post to this thread you said that cleaning the seals helped your retraction time.  How long did that last?  Are they still retracting OK?

I don't believe this style uses a conventional piston with seals and a rod wiper, I think the 2.0" (front) and 2.375" (rear) diameter rod acts as the piston.  The seal at the end is the only seal/packing.  The rod must have some kind of a stop on it to prevent it from pushing completely out

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Again, I don?t know your system or even what model it is but the typical single acting cyl does use the rod as a piston. The rod guide and seals are installed at the rod end of the barrel, not on a typical piston. A little different construction than larger cyls but still the same principles. If you wipe out the seal you will leak oil past the wiper. The top or cap end of the rod is where the rod stop is at. I think they are limited by a port relief but it should show this in your schematic if you have one.

Now I can put all my weight on it and they barely move, so that's like 2,000+ lbs of force.  I don't think new springs are going to help.

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FYI, I have never had to use blocks, etc for leverage, just a 2x4 laying on the ground. Now your issue sounds like an oil flow problem as compared to a dirty seal/rod issue. I think if it was a bad rod guide that was allowing the ram to drag in the barrel you would be leaking also. That?s a lot of force to put against the rod as compared to what I am talking about. I would suggest digging out the manual if you have one and take a look at the schematic to see what could be restricting your flow. You should have a flow control valve somewhere in the circuit that is used to keep the MH from dropping when you tell a jack to raise. This valve could be going bad or any number of other components, all which need to be considered before you decide it?s a bad jack. You might try and do a manual release to see if the jacks move any faster. I think that control valve takes everything out of the circuit and allows jack oil back to tank if you lose hyd power. Of course none of this does any good with all the jacks out. Maybe HWH can offer some other checks also.

ricknsharon said:

Question for SargeW. 
On your first post to this thread you said that cleaning the seals helped your retraction time.  How long did that last?  Are they still retracting OK?

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HI Rick, this was a pretty old thread, although the material is still relevant.  I in fact traded that MH in about 6 months later.  The silicone treatment and cleaning lasted about 2 months, then I had to silicone again.  That was the last time that I cleaned the seals though.  Still I never experienced the retraction problems that you are though.  I sounds like the valves are not letting the fluid flow back into the reservoir when the retract is activated.