Caliper rebuild?

[M3RACER]

For the second time now my right front caliper is starting to freeze up. Last year it completly froze, I decided to buy a new one but before I did I took it apart cleaned it up and it worked fine. What I am wodering is if I should buy a new or buy a caliper rebuild kit. What does a caliper rebuild kit actually come with? I don't want to have to go through this every year.

[Scott Yu]

It's pretty easy. The caliper rebuild kit is only $11-15 from a 3rd party retailer (try eurasian, don't know for sure if they have it) and consists of only the piston seal and the dust boot. Since you've had the thing apart before it should be really easy - replace the piston seal and the dust boot

Just inspect the piston and the cylinder very carefully for corrosion, and you might want to blow through the brake line hole with compressed air in the chance that some debris has gotten stuck in the channels. Either might cause the sticking you're talking about. I think someone told me that if you need anything finer than 1000-grit paper to clean up any corrosion in there, that it might be time for a new caliper; reason is that if you have to sand too much away to clean it, you'll be increasing the gap too much between the piston and cylinder.

Oh, there's a great trick for doing the seal, I found it here:
brake caliper rebuild writeup
Credit for this site goes to Neil Deshpande. BTW, this is an E30M3 caliper but the process is exactly the same.

hope this helps,

Scott Yu

Originally posted by M3RACER
For the second time now my right front caliper is starting to freeze up. Last year it completly froze, I decided to buy a new one but before I did I took it apart cleaned it up and it worked fine. What I am wodering is if I should buy a new or buy a caliper rebuild kit. What does a caliper rebuild kit actually come with? I don't want to have to go through this every year.

[UD///M]

Originally posted by Scott Yu
I think someone told me that if you need anything finer than 1000-grit paper to clean up any corrosion in there, that it might be time for a new caliper; reason is that if you have to sand too much away to clean it, you'll be increasing the gap too much between the piston and cylinder.

I think you might mean more COARSE than 1000 grit. Any finer and you pretty much have emery paper.

[fourfa]

no, he's right. any roughness can compromise the fluid seal. if there's corrosion that the 1000 grit can't take off, it's time for new pistons.

[fourfa]

wait, I didn't read that right. never mind.