Removing stuck master cylinder

[Mike26]

Hi there everyone, first post on here. I have a 1974 Series III 88 and have been doing upgrades as I go to get her back on the road. I am currently working on the brakes, and rebuilding the master cylinder. No matter what I try to do, I can'nt remove the master cylinder from the brake booster. I have removed both brake lines and the two bolts that hold the master onto the brake booster. I have taken flat head screwdrivers and wedged them between the two and gotten them to wiggle, but they still will not seperate. Am I forgetting something? Any internal bolts? Thanks for any information.

-Mike

[graniterover]

Yes. Take the top off the tower and you'll see two nuts, one on either side of the mc shaft. Remove the outer one.

[Moose]

I replaced the booster on my truck a few months ago and I had the same problem trying to separating the master and booster. They were stuck fast. What worked for me was simply stepping (lightly) on the brake peddle. Popped the master right off. Of course, now that you have the brake lines undone, this likely won't work unless you reconnect the lines. Once apart, I could see some rust around the rear of the cylinder where it enters the booster and this caused the stuckage. Brett

[Mike26]

well a friend and I removed the entire master/booster/brake pedal and tried about everything and it still won't come undone. we couldn't even get the pin to come out to release the booster from the pedal. I think a new master and booster are going to be in order. something tells me these are in rough shape.

[onecross]

try a really big hammer...

best of Luck!

[rovertek]

corrosion occurs between the master and the servo (booster) and if you pry on it or try forcing it you will damage the servo due to it being thin sheet metal, first try penetrating oil then if that does not work what ive done is carefully cut the ears of the masters flange off with cut off wheel (parts that bolt to the servo) then remove ears which will allow you to use large pliars and turn master until the corrosion breaks free, you will now need a new master but will save the servo just take sand paper and clean up corrosion inside servo.....

[kevin-ct]

Maybe just replace the booster. Did you check to see if the booster even works? It's a lot of work that you are doing to replace the master and after you are all done to find out the booster is no good. After all it's a 36 year old truck.

I try to replace everything at one time, so i don't have to work or think about that system again.

Just my $.02 cents.

Kevin

[Mike26]

Yeah, I have given up on trying to get the two seperated, I figure if the two don't want to come apart, there is a good reason. I am buying a set of 'good condition' used ones, and I already have the rebuild kits. Hopefully that will work and save me some cash instead of buying an all new master and booster. Now I just have to get the pin holding the booster onto the pedal off....