I purchased this motorcycle lift table, a Torin, BIG RED JACKS, item: T64001, about twenty years ago from PepBoys. It was a hydraulic only, foot pump design. I have used it regularly and it's been quite useful and reliable. It was a great find.
A couple months ago a puddle of fluid appeared under the hydraulic cylinder so I commenced looking for a cylinder seal rebuild kit with no luck and then for a complete replacement cylinder, still no luck.
I decided since I was going to have to find an entirely new cylinder, I'd upgrade from the hydraulic only cylinder to a pneumatic/hydraulic one and do away with the foot pump altogether.
Let the fun begin! I searched for a substitute pneumatic/hydraulic cylinder that I could install without modifying the cylinder mount points, but I could not find a cylinder short enough to fit in the available space. I spent quite a bit of time measuring cylinders and head scratching at Harbor Freight and Northern Tool but nothing would fit without major surgery.
I had a BMW R1100S (actually, I've had two of them) and frequented a forum dedicated to that bike. A forum member, Steve, started a thread describing how he had modified his MC lift with a pneumatic/hydraulic cylinder. To accommodate the replacement cylinder's extra length, he completely removed the cylinder mounts from the lift frame, fabricated and welded in new ones. Thanks to Steve for inspiring me to have at it without knowing the details of exactly how I was going to get it done. :-)
The following chronicles the modifications I performed for this conversion. The route I took differs from Steve's in that I was able to modify the lift's existing cylinder mounts to accommodate the replacement cylinder's extra length as opposed to fabricating completely new mounts.
The original lift table with the old hydraulic cylinder. See the puddle of hydraulic fluid?
The new, 2" longer, pneumatic/hydraulic cylinder from ebay.
The original cylinder's top mount with the lift collapsed. Not much room, in fact, no room at all.
The new cylinder needed more room to fully collapse. The top mount is marked for reshaping.
The reshaped top mounts.
A short length of tube was welded directly to the top perch of the new pump to minimize pump height.
The original cylinder bottom mount had space to be reclaimed but there was only about a 1/4" between the lowest edge of the pump's base and the floor when the lift was collapsed.
To reclaim space, the bottom mounts were reshaped and new holes drilled, lower and closer to the cross beam. For added stability, the pump's base is flat against its mount when the lift is at full height.
A lower pump mount was welded up (with a flat plate, a stand-off block and a short length of tube) and bolted to the pump's base. For maximum clearance, a keyed rod replaces the pivot bolt.
The modifications to the top and bottom mounts reclaim 2" in length. This yields just barely enough space for the new pump.
When collapsed, the new pump body impinged on the underside of the table top. It had to be clearanced.
The existing manual pump mechanisms, pedal and all, were removed from both the lift and new cylinder (old cylinder shown).
The new pump has a bump out on the base where the foot pump piston was. Therefore, the pump had to be mounted with the bump upwards to clear the floor.
This necessitated swapping the hydraulic release linkage from left to right. Consequently, the table frame was notched and a short tube welded in.
The hydraulic release mechanism's end barrel was notched to fit over the new pump's "T" release valve and a return spring was adapted.