Kip,
I did all four of the ones from my '40. The only thing you need to prepare for when you do this is when you take the little cover off. It's held on by three small screws. There's a spring loaded piston inside and it's going to want to make that cover fly across the room. I didn't find quite that much pressure on it. But if you can just ease that cover off, allowing the piston and spring to unload, then you shouldn't have any problems at all. What I found inside was some thick, black, oily gunk. I rinsed the chambers out really well with alcohol and used a bottle brush to get them really clean.
Also, I couldn't find any supplier of the cover gaskets. I just went and bought some cork gasket material at Napa. The fill plug, really just a big screw, takes a lead gasket. Again, couldn't find a supplier so I got some oversized lead washers from another Bolter here. I had to cut and trim them to fit. Inside the fill chamber is a little relief valve of sorts, if I remember right. you can clean it up with alcohol as well.
The "special oil" I bought from Jim Carter turned out to be "Gunk" brand Hydraulic Jack Oil. You'll probably be able to find it cheaper at Napa or ????
One last thing, after all the work I did to redo all four, two started leaking through the pressed fitting where the arm attaches to the lever inside. So, basically, I still have to buy two rebuilt units ... at about $120 a pop. But, now I kinda sound like an expert on these things, huh? It was a good exercise and the way I look at it I'm really not out anything other than some time, gasket material and oil, which I'll need anyway. Give it a try and let us know how it goes.
