Follow up on my calipers. Usable or not?
Posted by Remote-Department-68@reddit | projectcar | View on Reddit | 12 comments
I finally got the pistons out of my Scirocco Mk2's calipers. The photos are of one of the calipers (the worse-looking externally) after I wiped down its bore as it was full of gunge and lumps. The other one is in similar condition, I just didn't get around to cleaning it out. I don't think it looks too bad, but I'd like a second, more professional opinion. Thanks again.
DontBeHatenMeBro@reddit
The piston does not touch the bore, so it can be pitted. The piston seals on the rubber and not the metal. Note that the piston does has to be free of rust and pits to maintain a leak free seal.
Glum_Introduction755@reddit
It'll be fine. I'd take some emory cloth and clean those rust spots a little but it looks serviceable.
shotstraight@reddit
They need to be honed and a new seal installed. If you don't hone them, the corrosion in there will make the piston stick and drag the pads.
I-dunno-999@reddit
Clean them better and run them.
Poil336@reddit
I don't know what year you're dealing with or anything, but it looks like rockauto has "new" ones for like $40
Remote-Department-68@reddit (OP)
I'm avoiding buying new ones if I can still use the original ones.
v8packard@reddit
These have the seal in the bore, acting on the piston. The bores simply need to be clean and the groove for the seal in good condition. A new seal goes in, and they are good. The piston needs to be in excellent shape. Often you can buy a kit with new seals and pistons very reasonably. Super easy to clean up and rebuild.
Remote-Department-68@reddit (OP)
Didn't take photos of the pistons, but they're virtually pristine apart from some staining which I assume is just really old brake fluid.
v8packard@reddit
Then just clean them up. Clean the castings as well as you can, paint as needed. New seals and boots, assemble and go.
crescentfreshchester@reddit
Are you rebuilding the calipers or just cleaning them? It will probably be fine if you just sand it down evenly inside until its shiny. fine sand paper. Basically to make a crossthatch that is smooth. Then coat with rust reformer to prevent rust.
Remote-Department-68@reddit (OP)
I'm rebuilding them. The car had been sitting for 35 years in a barn, so I'm honestly surprised they still have some life left in them.
Deadlight44@reddit
Hard to tell how deep your pits are from the photo. I've run little hones in them before with new orings, grease and boots, been OK. Used to be some places offered to send them out to be remaned but idk if that's still around...