Master Cylinder Help
 

I want to refurbish the original master cylinder from my 77 T/A. It's been on a shelf for some 30+ years now. The piston is seized inside, and I have tapped on the cylinder, banged the unit on wood, soaked it in cheap solutions for weeks but it won't budge. I've attached pictures. Any help would be greatly appreciated. Thanks

Kroll oil worked for me. Filled the cylinder and let it sit for a few weeks. I would occasionally give a few taps on the piston with a brass punch and hammer and lightly hone the cylinder. Progress was slow but eventually it broke free when I applied air to back side of the piston.

Take a large punch, or something similar, and give the piston some firm wacks inward. This will break it loose and the spring on the back side will help to push it back out. You want to get the piston moving and possibly, eventually bouncing in the cylinder. Soaking in between helps too. As a last resort, I have drilled and tapped the piston and used a bolt to extract it.

Also make sure you have that little screw in the reservoir out. That holds in the second piston. That second one may be even more work to get out.

I sent mine to White Post for a fresh rebuild.

Thanks for the suggestions. Guess I'll keep tapping and soaking for a while longer.

Just send it out to get a stainless sleeve and rebuild. Whitepost has a good reputation for rebulding brake cylinders.

WhitePost was no longer stainless steel sleeving them as of 18 months ago. Instead using brass. I've used WP in the past, but no more.

What made them change materials? Does the softer brass tend to wear out?

Master cylinder rebuild
 

Today, my 1977 Trans Am master cylinder was returned from White Post Restorations. I am very pleased. I, and my local garage failed to remove the seized brake cylinder. White Post refurbished this part to look brand new. Nothing compares to an origional part. Thank you all for your recomendations.
This year I am thankful for all the help I receive from this site. I hope you all have a blessed thanksgiving.

Can you mention what that cost? I just replaced my original master fin a 78 T/A, I used a ac delco (yes its made in china) that gets great reviews & so far is working great.

But I kept the original to possibly rebuild. Anyone know if there is value to these originals or just nice to have an original even if its rebuilt?

From what I found this master is used on all kinds of GM cars & trucks from the 70s-80s as well as many other makes, so there is no part# specific to our cars and probably no real value since you could pull any original master from almost any car or truck.

White Post Restorations
 

Restoration of my master cylinder was $225 plus shipping. The place is located near Washington DC. I agonized for two months with what to do. I bought the AC Delco to replace my origional but just couldnt bring myself to install it. I, nor my garage guys could unseize the origional cylinder and I couldn't find replacement parts. Parts are getting rare for the 77. I'm so glad I had it refurbished. My car is all origional and the Chinese AC Delco's are just not the same. I hope this helps.

Thanks for the info. A little too pricey for me since my car is not 100% original, it's #'s matching engine/trans but more of a minor resto-mod and dont care to keep it totally original down to little things like a master cylinder that isnt T/A or vehicle specific. But thats great to do for all original cars.

The china acdelcos or other brands may be cosmetically a little different but functionally they are the same, and for many brands the quality is pretty good when made overseas compared to no name or cheaper rebuilt parts store stuff. For many items china is capable of producing excellent parts when held to a high standard by the company contracting them, its the super cheap brands that dont care much about quality control and only in it for money. Also the AC delco masters are new, not rebuilt... I'd rather have a decent name brand new part than a no name rebuilt part like many parts stores parts are.

With that said, I have owned this car for 20+ years and the brakes always worked fine, re-did everything with new parts like calipers/wheel cylinders pads/shoes & hardware, but over the last 10 years or so the pedal wasnt as firm or responsive as i remember or compared to my other cars, with the new master the brakes feel like a new car. Guess time will tell how long it lasts but all the positive reviews this part gets, it should last a very long time.

Thanks again for the info, I may hold on to the original one and rebuilt it myself with a kit... thats probably made in china. ;)

it sounds like it is seized in place you could try connecting a air hose to the front out let, but be careful because if it does come loose it will (the piston) come flying out