View Full Version : Help needed for Hydraulic Jack Problem

08-10-2007, 12:04 AM
After hooking the truck to the trailer the hydraulic jacks will "hesitate" before they retract to lower the trailer weight to the truck. It is almost like they are binding. We sometimes have to release the truck brake in order to get them to retract. We have sprayed silicone on them as suggested in the manual. Also, after they have retracted fully up, the one jack will slowly lower about 2 inches and remain there. The hydraulic pump motor seems to be working perfect as we never have any problem with putting the slides in or out.

Has anyone else had this problem and how did you solve it. Thanks.

08-11-2007, 11:04 PM
Lippert has owners manuals on line for the jacks and slideouts.


They mention contamination or dirt on the legs as a potential problem and also three other possibilities.
1. Hose damaged or unconnected.
Solution: Replace hose or reconnect hose.
2. Return valve inoperative.
Solution: Replace inoperative return valve.
3. Electronic signal is lost between switch and selenoid.
Solution: Attempt to retract jacks in manual mode. If successful replace control pad. If not, test for voltage drop between switch and leg valve. Repair bad wiring or replace defective board or valve.

I'm not sure which system you have but the same instructions are given in several of the manuals.

I hope you can fix the problem.

08-12-2007, 08:10 AM
Thanks for your help. The pump seems to work fine with the slides, so I think the jacks are binding someway?? The factory repair, in Elkhart, worked on a problem with the jacks this past April because the one jack would not stay fully retracted. It kept drifting down about 2 inches and remaining there (same as it is doing again). At that time they replaced that jack.........that is the same one that is causing the drifting problem again. Now in addition to that problem, both jacks very "slugish and slow" to "start to retract" after the trailer is hooked to the truck.
We are full-time, so everytime we hook - it is gives an uncertain feeling as to "if" they will retract so we can leave of "if" we will be looking for a repair service.

Will keep you posted.

Forrest Fetherolf
08-12-2007, 11:22 AM

The hydraulic jack problem could very well be air in the hydraulic cylinder and lines, a cylinder leaking internally or defective valve body . Air in the lines will cause the hydraulics to hesitate when activated, jerky operation, or creep in/out when not in use. To remove air in the lines, hookup RV to truck to take load off jacks, leave jack extensions retracted, and cycle jacks fully in and out several times. This will allow hydraulic fluid to displace any air in the cylinders and hydraulic lines.


08-13-2007, 07:41 PM
Thanks, I thought that might be the case. I found a connection that was NOT completely tight. I will give your suggestion a try when we hook in a few days.

11-11-2007, 07:28 PM
I have a Monticello and experinced the same problem. Took it back to the dealer who called Lippert and was informed by them to clean the flow control valves. After $550.00 I picked up the unit and guess what-- Still doing the same thing. Lippert now tells the dealer the flow control valve needs replacing. I am waiting on the part and will see if Lippert picks up the first repair under warrenty as it was their suggestion to try before replacing the part. Will let you know if this fixes the problem.

Tom of Ypsi
11-11-2007, 08:45 PM
My problem is the front jacks lose pressure while sitting in a campground. This goes on whenever it fels like it. I can be perfectly level for 2 or 3 days then one day they start going down on their own. This has also affected my slides. Sometimes when raising or lowering the front jacks the slides will go in or out depending on which way I am making the jacks go. Any suggestions??

11-11-2007, 08:55 PM
Have you marked your reservoir when you park and then check in a couple of days to see if the level has changed? Sounds like you are leaking back through the system-or-an external leak and losing fluid, causing loss of pressure. Just a guess, but something to look at.


Tom of Ypsi
11-11-2007, 10:21 PM

I have checked the fluid level and all seems ok. I have looked for leaks and cannot find any. This is why I am stumped. There is a mobile rv repair in the park but he is busy until Tuesday, meanwhile I keep jacking up the landing legs whenever I feel I am going to fall out of bed:eek:

11-11-2007, 11:27 PM

Have you tried turning all of the slide valves off and see if it makes any difference?

Tom of Ypsi
11-12-2007, 08:05 AM

Yes I have turned off the valves and was surprised when I left and came back several hours later to find my rear jacks in the air. Spent the day with Bob & Christina (Big Mama) on Sat for a Veterans Day celebration, lunch and BS'ing. I guess I will have to wait for the repair guy to evaluate the problem and hopefully it will be covered under the 3 year warranty. Thanks for your help.

11-14-2007, 01:02 AM
We are the people that started this thread. Our jacks are still causing the same problem. Lippert has been very nice and tried to help us over the phone several times. They also suggested a repair shop to take the coach to. Since we are settled in AZ for the winter and our campsite is VERY hard to get into, we are thinking of taking it to the factory on the way north this spring.

Please post the cause of this problem if anyone gets it fixed.


11-14-2007, 01:14 AM
Is your battery disconnect turned on? I know it sounds strange but that worked for me

Tom of Ypsi
11-14-2007, 09:14 AM
Make sure that your valves are turned all the way to the left (counter clockwise) Mine were turned to the middle of right & left. When I turned mine off or I thought they were off I turned them all the way right. I still have a leak but it seems to be getting better. Bled off the solenoids in case there was dirt in them.

Since you are parked for the winter see if there is a mobile RV service, that is what I am using. He is in constant contact with Lippert and he is also in te park I am wintering in.