Levelling jacks not retracting

[edog1973]

The four jacks on Ziggy (that's her name now, story for another post) extend just fine but I'm having an issue with them retracting.  When there is weight on them they retract just fine.  When they get just to the point where the weight is off they stop. I can use a small crowbar to push them up another inch or two and then they finish retracting and fold up just fine.  I'm wondering if the springs are old and don't have enough tension any more?  Any ideas?

[legomybago]

Maybe their is a check valve in the system that's crapped up?? I would think if the spring was too weak, it wouldn't curl/fold the jack up into the closed position at all? Maybe some fresh fluid would help.

[CapnDirk]

My jack did the same as edog but there was no pushing it up.  Research found a thread in the UK of someone that had rebuilt some and had to ream the bushing inside that can swell (phonelic bushing).  It was a pain to work on as there is a 2.25 cold rolled steel plug welded in the top, and the foot is welded to the bottom of the ram.  No way to work with it without having to cut BOTH ends open.


You might try new springs but I would do one for the $30 and see how it goes.


I'll post some pics of getting it apart when I get back to it.  The front jack problem is like there is no pressure going to the jack (just looping in the manifold block) but I have taken apart the releif valve and pressure valve and found no problems.

[Rickf1985]

Make sure you have good, brand name fluid in there. I have had heavy equipment that had cheap fluid and the cylinders bond up something terrible. Changed out all the fluid and it got a little better, changed it again and things got much better with no binding. Quality counts when it comes to fluid.

[CapnDirk]

Your post interested me Rick.  I wonder if those plastic bushings are swelling up due to incorrect fluid someone added down the line.  I've seen posts to use Dexron, but I wonder specifically what the HWH stuff is.

[Rickf1985]

Well, I can tell you that Dexron is NOT hydraulic fluid as such. The equipment I was working on was an excavator and the owner hap put cheap tractor supply hydraulic fluid in it after a blown hose. When he blew the hose he ran the machine all the way back to his garage which was at least a 45 minute run back so he lost  enough fluid that he barely made it back, 55 gallons of ultracheap fluid. He figured hydraulic fluid is all the same. The manufacturers all specify certain ratings for the oil in their machines, Ford uses 134 hydraulic oil for instance. You will generally find all the quality oils list the manufacturers ratings right on them. In his case he could not figure it out and had resorted to using his backhoe to do jobs that were just too much for it. I happened by one day and I saw him trying to do a job with the back hoe and asked what was wrong with the excavator. He told me to try it. WOW! It just did not want to do anything smoothly especially anything that required drifting down under gravity. He told me about the hose and the large amount of oil and maybe he burnt the pump but the pump was not affecting the float settings so I checked out the oil and bingo. We drained the entire unit including the cylinders and refilled it and right away it was better. Still a bit rough but better so he said lets do it again, his money! 55 more gallons later and it was as smooth as ever. The no name crap just did not have the lubrication qualities of the branded stuff. It also foamed which certainly didn't help.

Basically what I am saying is if you decide to change out the oil, and it sounds like you should, then go with a branded oil. I use Tractor Supply oil but NOT the super cheap stuff. You will see on the label where it is rated for all of the major brands.

[Rickf1985]

Just as an aside............ Western snowplows call for transmission fluid while Myers plows call for their own special fluid and it is totally different than transmission fluid. Blue and very thin. I know people that have put transmission fluid in Myers and have had no problems and others that have pumps fail on them, especially later pumps.

[CapnDirk]

Looked it up at HWH, a quote from their FAQ.


What kind of fluid should I use in my system?
The use of HWH Specialty Hydraulic Oil is recommended but Dexron® or multipurpose transmission fluids can be used if necessary.  DO NOT use hydraulic jack oil, brake fluid, or power steering fluid.


So, no real info on what their stuff is.  I would assume that they feel that the Dexron would be compatible with their stuff already in the tank

[Rickf1985]

Sounds to me like transmission fluid would work, again though, branded fluid, not junk stuff.

[bluebird]

I just went though this with my Daybreak. If you can push them up with a bar, you may be able to clean the shafts with WD40. I used Kroil to help on a couple of mine. I ran mine up and down several times using the Kroil on the shafts. The fronts started working OK but the rears never did. Eventually blew the seal one one of the rears. Take the number off the jack and call HWH to see how much it cost to rebuild. They will rebuild them much cheaper than you can buy new. They will give you a most cost to rebuild, but may not cost that much when they find out what is wrong with them. If the shaft is bent, even just a little bit they won't retract. They gave me a cost of $330.00 each worst cost to rebuild mine. I put blocks under my jacks and ran them in and out several times before the fronts started working. The PO of my coach hadn't used them in years, because the motor was out. So they had rust up inside the seal area.


If you do get them working, work them several times even if you don't need them. And keep the shafts cleaned with WD40.

[CapnDirk]

Thanks Bluebird.I did contact HWH a few weeks ago.  A woman answered and I indicated that I would like to know the rebuild cost of a 9000lb jack (based on other threads saying people had had their jack rebuilt).  She took my info and said someone would contact me.  I got a voicemail a week and a half later saying "my name is yada, if you need to order parts please give me a call"  Not encouraging for a company of many years.


I have the jack half way apart, and should have it the rest of the way apart soon.  Will start a topic of "autopsy of a HWH jack".  I don't think it's a bent ram, as there is usually a difference in resistance once the arc of the bend passes the bushings/sleeves/whatever inside.  Mine is locked full stroke necessitating a 5lb hammer for movement.

[Oz]

Will start a topic of "autopsy of a HWH jack".

I like that...