5th Wheel Slide, Air Cylinder Replacement

The air cylinder is shot on my Holland 5th wheel (FW3500). FleetPride wants $140 for a new one. Looking online I'm seeing Velvac and some other knock off cylinders. What say all y'all about the aftermarket ones? Any good? Are any of them rebuildable so I can service it down the road? The one that was on there is welded shut. I also see Holland is making aluminum cylinders to replace the steel ones, anyone use one of those?

Looks like my truck was never plumbed for it too so I'm going to have to run air lines and add a switch to the dash. Good times.

 

I have the whole thing torn apart right now. I'm sandblasting everything and repainting. The only parts I need to replace are the cylinder and pins to hold it, everything else looks good.