First of thank you for this forum. I have a 24 Classic that has an issue with lifting. The top will only lift about 2" and sinks back down with the electric as well as the manual lift. Here is what have tested after searching through this forum :
-the top can be lifted with manual floor jacks(no binding)
-the cables are all in good shape and tightening together
-the fluid is at the top of the reservoir
-I have had my wife operate the manual switch while turning the manual release valve back and forth.(the top will go up two inches with it closed)
- fluid is returning to the reservoir while the pump is running(valve closed)
- no leaks on the cylinder or lines(under camper)

From what I have read from this forum, I am thinking now there may be a failure internal within the cylinder. Does it seem like this may be the case? When under the camper it seems to remove the cylinder, the camper will need to be raised in order to have enough space to remove it.

Hi, gulf. Sadly, it DOES sound like your hydraulic seals are leaking and will have to be replaced. I THINK you said you had moved the manual lowering valve to both extremes and that did not help. If it were open, the top would not stay up either.

I don't think you really have to raise the trailer to get under it to remove the hydraulic cylinder, but it may make the process easier. I know I can get under the trailer with the wheels on the ground and I'm not a "small" person. Another moderator, Treeclimber, has serviced his hydraulic system as I recall and he may be able to help you. You might also look for posts on this topic by him.

- Jack

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Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter, Fan-Tastic Fan, LiFePO4 battery 12V DC Electrical System
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew