[TimsTA]

Can someone advise as to how critical pitting is on the surface area inside a caliper. I have sanded and honed but cannot get rid of it completely. Would like to keep my originals but if it’s a safety issue I’ll replace them. Thanks for any input.

[b-man]

I would have them sleeved.

There are shops that specialize in this type of thing for brake components.

Surely it’s cheaper to simply replace them but if originality is important then they can be saved.

[Stuart]

White Post is one place that sleeves them, but there are others. https://whitepost.com/brake-sleeving...ding-services/

[TimsTA]

Thanks for the info. I know the piston rides pretty much on the O Ring but wasn’t sure if there just needed to be a complete smooth surface. The fluid probably needs a smooth surface also I’m guessing just to form a good pressure on the piston. Probably just get replacements and keep originals to maybe sleeve sometime. I’ll have to most likely eat the core charge too. Do the numbers on the calipers indicate a date code? If not then I’m not worried about keeping them. Thanks again

[67drake]

If it were mine, I’d run them. Like you said the piston rides on the seal. I’d throw out a piston with any pitting or damage, but not on the caliper unless it way worse than that.

[Sirrotica]

You can try a rebuild kit, and see if it leaks, it likely will be fine. I've rebuilt many pitted calipers myself due to the fact that when rebuilt, by mass rebuilders, they don't always get it right. I prefer to rebuild all of my own, and before I retired I rebuilt most of my customer cores.

Usually a ridge of rust is what locks the piston in the bore, the pits only have the liklihood to leak, but they have to be quite bad before they cause leaks.

If I do them, at least I know who did it, rather than put on calipers, have a problem, remove the problematic part, and return it, and hope the second replacement is better than the first. I know for a fact rebuilders don't sleeve their cores, they usually blast them with abrasive, and put new seals in them, maybe a piston if the piston won't clean up well enough. They put in new slide O rings and blast the bushings, nothing is high tech, it's just a hydraulic piston and cylinder with seals. As long as the parts that slide over the seals are reasonable smooth, they work fine.

FWIW, in 2010 I bought a 1993 K3500 with sticking calipers. The truck had 217,000 miles on it at that time. I rebuilt both calipers, and retired the truck in 2022 with 270,000 miles. Both calipers were still working just fine when I quit driving it. Both castings were pitted back in 2010. I cleaned the rust up, polished the pistons, and never had any problems with it for 12 years, YMMV.

[TimsTA]

Thanks, I had spent a little time cleaning these up and had bought new seals,O Rings,ect. Painted them and put them away until I was ready for them. I was concerned about the pitting then when I stored them away. Following what you said, I will probably just move forward with them and keep a close watch. Thanks fo all the help & advice.