:welcome: Please forgive me for not noticing that you are new to irv2. It is great to have another member.
I don't think the pistons are in the walls. Try under the slides. Is your system HWH?
I would visually examine the hydraulic pump area and all connections for leaks. You may have to spray things down with a de-greaser of some sort and then hose thing off. Find each piston and look for leaks, especially for the room that is moving. If you don't know how to gain access to view a piston Winnebago support will help you. Call or email them and provide you coach SN and VIN.
If no leaks are found tell Winnebago this. One of your slide solenoids is leaking in the manifold and needs to be replaced or tightened. The folks at the factory support line will advise you.
Do you have the HWH owners manual? You may find some helpful troubleshooting tips in it.
As you look into this problem plan on getting very dirty
. The fluid is nothing more than ATF without dye. But it still a mess to work around.
I look forward to what you find. You never know who you might help with your report.