Went the raise the trailer to load up and get ready for this weekend, and once the landing gear makes contact with the ground and put under the load of the trailer, it quits extending and wont lift the trailer. it extends up and down like is should, the fluid reservoir is full of fluid. Do i have a bad cylinder seal? What else should I check? Thanks for any help.

If the fluid is full and no leaks, it must have Air in the system

Best way to purge? i cycled it several times. And where would it get air from? I always retract it and leave it on the mechanical gear so no loads left on the hydraulic system. Thanks.

Does the pump continue to run and not lift or does everything stop when the load is applied? Low voltage will shut the pump down when the load is applied.

internal seals in cylinder or pressure reg possible.the pump is putting fluid on one hose,undo the other hose and run pump. if fluid continuosly comes out its seals.if only a small amount while shaft is moving then something else.my guess would be pressure relief valve

quote:

Originally posted by Lincoln:
Does the pump continue to run and not lift or does everything stop when the load is applied? Low voltage will shut the pump down when the load is applied.

Pump continues to run as long as you hold the switch. Just doesn't change pitch and doesn't lift the trailer. But does travel up and down fine when not under a load.

What Rusty said^^^

quote:

Originally posted by rusty:
internal seals in cylinder or pressure reg possible.the pump is putting fluid on one hose,undo the other hose and run pump. if fluid continuosly comes out its seals.if only a small amount while shaft is moving then something else.my guess would be pressure relief valve

where's the valve typically?

i havnt looked at that close and assuming big foot jack,but likely incorparated in pump

maybe google brand for parts or schematic

Thanks for the advice guys. guess its back to old school hard work for the weekend, raising the trailer the hard way!

quote:

Originally posted by rusty:
internal seals in cylinder or pressure reg possible.the pump is putting fluid on one hose,undo the other hose and run pump. if fluid continuosly comes out its seals.if only a small amount while shaft is moving then something else.my guess would be pressure relief valve

I'd vote for the seals in the cylinder.

My travel trailer has hydraulic slides. After replacing the pump (it worked but leaked) I went to extend them and one opened and the other two would not. Ended up having to take the bottom apart and getting the cylinders rebuilt. Now works like a charm.
Rusty is right.

Dave

quote:

Originally posted by Mike Frizie:
Thanks for the advice guys. guess its back to old school hard work for the weekend, raising the trailer the hard way!

If it has 2 speed legs make sure it's in low gear.. Ask me how I know...

Dave