Slide out drifts open

Sounds like a hydraulic check valve is letting fluid seep by and allowing the slide to extend. The quick fix is to get a pair of these locking poles to keep the slide closed.

Our last Terry came from the factory with these poles to take the pressure off the mechanism keeping the slide closed when going down the road. Just have to remember to remove them prior to opening the slide.

A previous 5th wheel trailer we had would creep out. Didn't notice it sitting till the 1st trip when I checked the outside mirror. Lordy it was out about 10" or so. I broke the wife's broom stick off to the right length where it would wedge in at the top/center inside the trailer and hold the slide in. After the trip I made a better pogo stick. Years back many 5er trailers with a slide or tip out came with a pogo stick from the factory to keep the slide out in while traveling.

We use two pogo sticks to keep the slide in even tho it is electric.

JIMNLIN wrote:
A previous 5th wheel trailer we had would creep out. Didn't notice it sitting till the 1st trip when I checked the outside mirror. Lordy it was out about 10" or so. I broke the wife's broom stick off to the right length where it would wedge in at the top/center inside the trailer and hold the slide in. After the trip I made a better pogo stick. Years back many 5er trailers with a slide or tip out came with a pogo stick from the factory to keep the slide out in while traveling.

We had a 1998 Holiday Rambler Alumalite that came with 2 slide out enforcing bars that had a tensioner built in.

There was a piece of steel plate on the backside of the slide room that these set on

BurbMan wrote:
Sounds like a hydraulic check valve is letting fluid seep by and allowing the slide to extend. The quick fix is to get a pair of these locking poles to keep the slide closed.

Our last Terry came from the factory with these poles to take the pressure off the mechanism keeping the slide closed when going down the road. Just have to remember to remove them prior to opening the slide.

Are you saying the residual pressure is causing it to move? Seems like the pressure would equalize at some point and movement would stop.
I agree locking poles, Pogo sticks or some other type of pole will stop movement. it did not do this when we first bought it. The rear slide (2) is a bunkhouse so there is no way to get back there once slides are pulled in.

I've never had any trouble with it moving while traveling.

As the hydraulic pump moves fluid through the system that causes the slide to retract, there is a check valve that stops fluid from flowing the opposite way once the pump stops. Not sure I would call it "residual pressure" although I think you get that the effect is the same.

Where is the check valve? In the pump?

No idea, and that's only my guess as to what could be wrong. You could also have a leaking seal, damaged hose, etc. Lippert made several types of slide systems for Forest River, I'm guessing yours is hydraulic because of the way they all the slides work together.

Maybe start on the Forest River Forum and see if other owners maybe had/fixed a simliar problem.

Hyd slide out creeping out when closed is caused by

1. Air in system. Cycle slides in and out 3 to 5 times to purge air
2. Internal or external leak on slide actuator
3. Hydac solenoid valve .. only one for hyd slides nit fully closed in manual override mode CW) or sticking valve

DO NOT use a bar or anything else to keep hyd slides closed .. 2000 psi is used to keep slides closed or open and if leak is internal on actuator your can tear up your slide by locking in place

ChuckSteed wrote:
Hyd slide out creeping out when closed is caused by

1. Air in system. Cycle slides in and out 3 to 5 times to purge air
2. Internal or external leak on slide actuator
3. Hydac solenoid valve .. only one for hyd slides nit fully closed in manual override mode CW) or sticking valve

DO NOT use a bar or anything else to keep hyd slides closed .. 2000 psi is used to keep slides closed or open and if leak is internal on actuator your can tear up your slide by locking in place

Thanks for your reply. I'll try purging air out this weekend. I know it's not an external leak on cylinder because no sign of fluid anywhere. Could be an internal leak. I'll see what happens after I cycle the slides in and out a few times.