I got a set of slightly used (less than 1000 miles on the rotors and calipers) '69 disc brakes with the wagon. The rotors are like new as are the bearings, etc. I plan to clean things up and use all the parts again except the pads.

The calipers seem fine too but I want to disassemble them so I can paint them and put in new seals while I'm at it. An added reason to take them apart is to clean out any remnants of brake fluid remaining as I plan to run silicone brake fluid. Regular brake fluid and silicone fluid are not compatible.

My question is: how hard is it to take these calipers apart and how is it done? Will compressed air push out the piston safely? They seem pretty simple mechanically, I just want to know what I'm doing before I get started. I suspect I can buy rebuild kits (an o-ring and a seal) locally. If not, I've seen them in the Chevelle parts catalogs.

TIA.

Yes, compressed air. Just be careful, I about took the end of a finger off. If the piston gets stuck in the bore... DO NOT just put more air to it!!!! If they are not rusty/pitted then a new o=ring and seal will freshen them right up. Maybe sand blast them while you have them apart.

Cam

I have my own media blast cabinet which does a nice job cleaning things up. I'll start with low air pressure to get the pistons out. Everything else has cleaned up great, I assume the calipers will be the same unless they've sat around too long and got some pitting inside. If that's the case I guess I'll just buy new rebuilt ones.

Put a 1 X 2 (or a wood hammer handle) in the caliper where the pads would be. Blow the piston out with a rubber tip blow gun. Don't get your fingers in the way, 'cause when it comes out...Kaboom!

You'll spend as much for the rebuild kits as you will to get rebuilt calipers, and the kit won't have a warranty.

Pitting in the caliper bore is not too terrible. Pitting of the piston is. Piston needs to be "perfect".

You'll want compressed air to put the piston back in the bore. Clean the seal grooves, and then install the square cut seal,(lubed with brake fluid) and the dust boot. Then put the piston (lubed with brake fluid) on top of the dust boot, and GENTLY blow air into the caliper. You are trying to "inflate" the dust boot so it slips over the bottom of the piston. Tough to describe, but you'll see when you try it. Don't break a finger with too much air pressure. And, yeah, it sounds like a whoopee cushion until you get the piston settled inside the dust boot. This is a 5-second deal when you've done it a few times. From there, use your hammer handle to shove the piston past the square cut seal. Another 5-seconds.

Single piston calipers are EASY.

Reman calipers here are $30 each and the pads are included, after a $25 core. Didn't make sense for me to mess with the old ones on my Elky and then pay another $30 for pads. My .02.

Reman calipers here are $20 each and rebuild kits are like $3.