I'm rebuilding some junkyard calipers and there's quite a bit of rust inside the pistons (in the cavity). The outside looks fine and should seal up well. I've tried wire brushes but no real luck. Is this a problem? Should I look for something a little stronger than brake cleaner to try to remove it? At what point are new pistons necessary?

 

when the piston is rusted and pitted beyond repair.....

 

Out of curiosity, how much did the rebuild kit cost? I paid <$50 for re-man'ed front calipers.

 

Hello, operator could you give me the number to 911?

No, Not a problem

 

Seal kit was about $20/side I think (I bought this stuff months ago and only now have the time to put it together). And I have a track date coming up and my current calipers have issues.

 

It's normal for the inside of the piston to rust. That's not a big deal. Make sure the outside is good, which is the part exposed to the fluid, and has the seal.

Warren

 

Yup, inside rust is no problem. Make sure you have an air compressor to blow the piston out of the caliper. I rebuilt mine myself and wasnt that big of a deal. Its a tad tricky to switch the piston seals, but nothing too bad. Im kinda pissed because the only reason I was rebuilding was because of the piston dust boot, which started to crumble AGAIN after the next HPDE. Oh well.

 

If you really want to clean it out get a small wire brush for a drill, or a dremel type tool and use a drill.

 

Okay, here's an update. I ran over to Autozone (about 2 blocks away, lucky me) and they had this rust removing jelly stuff. Painted it on and in 10 minutes about 75% of the rust was gone. Neat stuff. Should finish up today. Thanks for the feedback.

siisgood00 - don't have an air compressor but I cheated. I installed a blow gun on to my 9 gal. air tank. Didn't take much at all to pop the piston out.

Now I just need to decide on a nice cheap track pad for HPDE's. I'm thinking pep boys ceramic. Time to get some ghetto in me.