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I took apart an old caliper core I had laying around and figured I’d ask a few questions of those in the know. If it matters it’s a rt rear from a 77. Anyhow I’ve taken some various pictures. First off, is this worth rebuilding? Second does this appear to be stainless sleeved? Third, Im assuming this is what is referred to as a lip seal? If this is worth rebuilding are there any things to look out for or is it pretty straightforward? Thanks
Are they Delco Moraine castings? The bores have been sleeved. They will need a honing and thorough cleaning with denatured alcohol prior to rebuilding. Lastly, if you intend to rebuild them, I would use O-ring pistons. Jerry
Yes it is a Delco moraine casting. Thanks, I thought it looked sleeved. Not sure what the plan is, just been laying around forever and figured I’d see what one looked like if I took it apart.
is that a lip seal style
Last edited by danh77; Yesterday at 11:00 AM.
Reason: Added info
Yes, that's a lip seal. I still use them in my cars with no issues. What brake fluid you run has a bearing on what seals you can use. (DOT 5 silicone fluid requires EPDM seal material.)
This caliper is definitely rebuildable. I agree, sleeves have been installed, so there really isn't much else to do other than check the inlet fitting threads and seat is good. Polish the bores, clean well, and assemble.
Yes, that's a lip seal. I still use them in my cars with no issues. What brake fluid you run has a bearing on what seals you can use. (DOT 5 silicone fluid requires EPDM seal material.)
This caliper is definitely rebuildable. I agree, sleeves have been installed, so there really isn't much else to do other than check the inlet fitting threads and seat is good. Polish the bores, clean well, and assemble.
Any suggestions what to polish and clean with? Thanks
Any suggestions what to polish and clean with? Thanks
I use silicon-carbide wet/dry sand paper, flushed with a light oil (i.e., WD-40, kerosene, 3-in-1). From the surface appearance in the pics, I'd probably start your bores at 600 grit, move to 1200 grit. New sleeves are surprisingly polished, so 2000 & 3000 grit wouldn't be silly. You don't want to remove much of the surface, so go easy. If you can catch a fingernail or pick tip in a scratch, it's probably best to core-swap them rather than try to sand it out. Once smoothed and polished, clean the passages and bores with brake cleaner, followed by denatured alcohol, as Tampa Jerry said.
If you drive the Vette a lot then the lips seals work fine. If it sits, like a lot of our cars do, then you want to use the O-rings. The lip seals tend to relax if they aren't used a lot and then they will leak while the car is sitting. I switched mine over to O-ring seals and have not had any issues. I don't remember if I reinstalled the springs or not. I have seen literature that says that you don't need them, but that was after I redid mine. These older Vettes are very hard to push, and I always thought that the brakes dragging was part of that issue.
Caliper questions for anyone who’s rebuilt one
