General Tech Girling Brake help needed

[JPSmit]

Some of you will know that I am currently restoring a Vauxhall Viva GT. The other week I discovered to my great delight that it shares at least part of the brake system with a Spitfire. Thus I was able to get the slave cylinder retaining clips, the brake pad retaining clips and springs and the rubber weather covers new and locally rather than NOS in the UK. Now however I am trying to get the pistons out of the front calipers. I have tried the instructions for TR6'S from the Buckeye Triumph website. Three of the pistons do move - and one, maybe, I bent the clamp. I tore out the rubber gasket, and made an air tool that attaches to a bleeder screw. Nothing.

any other ideas? I am a bit stumped at this point.

thanks all!

 

[TR3driver]

Restrain the piston that moves, and get more pressure. One solution, given by Bob Schaller in "More BS", is to adapt a grease gun to the inlet fitting. A full size grease gun can develop 1000 psi or more.


Another is to hook it up to the system (blanking off the other ports in some fashion) and stomp on the brake pedal.

Yet another is to fill the interior of the caliper as much as you can with solvent (eg Gumout) and block off the port with a bolt and nut (maybe a copper washer if you've got one handy), then start heating the caliper with a propane torch. The heat will melt the seals and boil the solvent, forcing the piston out. Best to wear face protection though, as the escaping vapor may catch fire, producing a brief ball of flame.

 

[bnw]

Don't get in the way of that piston if it comes out under extreme pressure. It will probably scare the crap out of you as well.

 

[TR3driver]

Oh, yeah, forgot to mention, it's best to have a piece of wood for the piston to hit, especially when using that last method.

 

[JPSmit]

Thanks all - I was on the road today so, will try again tomorrow. I don't have a full sized grease gun, might be able to get some more air pressure. I do like the torch idea.

And, have used air to blow out the pistons on my MG, so, am definitely aware of the "bang"

will keep you posted.