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MG MGB Technical - Brake Caliper Piston Retraction

I am about to rebild the front brakes on my MGB and after previous problems pushing back the pistons into the caliper I have decided to buy a retraction tool.

Problem is there seems to be lots of different ones on the market does anyone have a recommendation as the best type to buy?

Graham
Graham

I have never used a retraction tool. just insert a good strong bit of wood and leaver. if the top is off the master cyl. then it should be easy to do. if it is difficult i would suggest that you strip the pistons down and clean up so they havea free(er) action.
Cecil Kimber

I just did that job this morning.
I used the only kind I've ever known. It's really a compression tool. It has a knob at the end of a jackscrew and a slightly curved oblong plate in the middle. I think you must have seen these before. My pistons were not in that great a shape. At first I tried the wood deal, but I couldn't get the leverage or something. Then I remembered I had the tool, it took 2 mins....

Good luck - Frank
Frank

Frank, I think you are describing a C clamp, Thats what I use. Don't know what type tools are available in the UK, most tools here are made to work on a single piston caliper with one side open. Those will not work with MGB calipers. To keep the master cylinder from overflowing when pushing the pistons back, I open the bleeder, connect a hose and the fluid goes out the bleeder into a pan or jar. It's easier to push the piston in using the bleeder to release the fluid. FWIW, Clifton
Clifton Gordon

vISE-GRIP makes a large c clamp type vise grip that is the hot set-up, get two so you can leave one holding the right piston while the right rotor is being resurfaced and use the other to compress the left piston.As Clifton said above,an open bleeder will make it slightly easier to compress the piston but it also keeps the caliper fluid [the bottom of the system where the dirt settles] from being forced in to the master cylinder-RIC
R E L Lloyd

Graham. Not sure what you are trying to do. I normally find that the brake pads can be removed, then I remove the caliper assembly and remove the pistons from it. Are you trying to get the pistons back into the rebuilt calipers? Les
Les Bengtson

I use a Girling tool that I bought from the MGOC a few years back. It's basically a flat bar with a handle attached (image a L shape with the long arm being the handle). You just slip it the open and twist - no fuss no damage, just equal force applied to both sides of the piston at once.
Miles Banister

I use a drill press clamp - with a 3/16" thick flat bar of steel bolted to it. Works on one piston at a time.

In the U.S., Harbor Freight Tools has a drill press clamp for about $7.
Daniel Wong

Back in the 1960s when I first changed the pads on my MGB (new disc rotor cost 28/-twenty eight shillings!; that's £1.40p in metric)*, I used the worn out brake pad with a large carpenter's G cramp to wind back the caliper piston, having first thoroughly cleaned it all. I still use that same G cramp and did so when I changed the pads on my Rover 220 Coupe the other day. It works on most more modern cars too.

Essential to clean the exposed parts of the piston before retracting.

*Note to self ... must resist the temptation to digress ..lol
John McFeely

Plain old 6" C Clamp is the way to go. You don't need the fancy tools for this job
gerry masterman

Try this link for a tool that works perfectly on MG calipers it pushes both pistons back squarely and with no damage to piston bores.

http://www.justoffbase-tools.co.uk/tools.asp?parent=2I3583P1415M0
Howard

I have always used my big channel lock pliers and never had a problem. Squeeze and release e few times and in they go. Lower the fluid level in the master cylinder resevour FIRST so you don't give your heater deck a bath!!! That is if we are talking about just replacing pads. If you are replacing piston seals, we need to start over.
Mark
MLS Somers

This thread was discussed between 30/08/2003 and 01/09/2003

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