The compressed air solution really works...in my case even for some
fairly corroded calipers...caution tho...as mentioned below...it takes
only a little pressure...120 pounds blew the damn pistons across to
the other side of the two car garage behind a pile of miscellaneous
parts for the sandblaster...took a while to find the darn
things...course I was going to replace with new anyway...but consider
the possibilities????
PMQ
73 TR-6
72 GT-6
69 GT-6+ (2) one with new brake pistons...
______________________________ Reply Separator _________________________________
Subject: FW: Caliper Pistons Problem
Author: "Vincenti, Ross" <VINCENR@transamerica.com> at smtpgate
Date: 10/3/96 10:54 AM
On Thurs, Brian responded to my query about brake pistons:
Rust: I polished my brake cyls with 600 grit paper and a litle silcone
brake
fluid. Some traces of lost metal remained, but had not effect on
performance. Never leaked since.
Reinsertion: This could be a tough one. I think I used some clamps. They
give enought force. The trick is not to bugger up the rubber ring. Again,
use some brake fluid as a lubricant. And assure that the direction of force
is exact.
I am surprised your question was not about getting the pistons out. One at
a time can always be forced out with the brake pedal, but you have to do the
job with the calipers on the car and service one piston at a time.
Otherwise
use a plumbers expandable compression rubber pipe plug (the kind where you
tighten the nut on a couple of washers squishing a rubber donut in between).
++++++++++++++++++
Actually, getting them out was easy. Just used some compressed air to blow
them out through the brake line. Works great and very little pressure is
required.
I had thought about using some fine emery cloth or steel wool to clear off
the rust. Thanks to everybody for the responses, I'll pick up some super
fine grit stuff tonight on the way home. The reinsertion part may still be
tricky. I put in all new rubber seals, etc, and I think that is what is
causing the friction, as the pistons will go in about one eighth to one
quarter of an inch and then stop as though they were hanging up on that
brand new grippy rubber gasket. I like Brian's idea of using a clamp
arrangement and some fluid as a lubricant.
I'll let you know if it works tomorrow.
Ross D. Vincenti
64 Spitfire 4 (undergoing surgery)
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