british-cars
[Top] [All Lists]

Re: 120 discs, MGA calipers

To: reilly@admail.fnal.gov
Subject: Re: 120 discs, MGA calipers
From: Roland Dudley <cobra@cdc.hp.com>
Date: Wed, 20 Oct 93 11:45:13 pdt
> 
> MGA calipers with stuck pistons: drop them in a bucket of diesel fuel for a
> week, maybe a month. Yes, I said a month! Then you need three things: 
>patience,
> more patience, and even more patience. If you can't find any of the above, try
> a penetrating oil called "KROIL", our shop has had good luck with it. Heat up
> the outside of the caliper around the piston and drop ice cubes or liquid
> nitrogen in the cup. Eventually the piston should loosen up so pressure from
> air, brake line, or grease gun should get it out. Don't separate the halves
> until you've tried everything else.

I think I have to strongly disagree with this last statement if the
calipers have internal fluid passages and you use one of the above
liquids to free up the pistons.  There is a rubber seal between the
halves of calipers with internal fluid passage which very likely would
be damaged by diesel fuel or KROIL.  If, on the other hand, the
passage is through an external pipe, then the above advise might be
okay as long as every trace of diesel and/or KROIL is removed; very
difficult even if the halves are separated.

If I were to use pressure to free up the piston, I would limit it
to one of the following:

   air
   brake fluid
   water

Of course alcohol would be okay too but I think one of the above would 
be a better choice.

Roland


<Prev in Thread] Current Thread [Next in Thread>