- Thread starter
- #21
Just finished the test drive, that seems to have cured the problem. Thanks again for everyone's response, ideas and inputs.
Poser! Expert Brake HELP! needed
- Thread starter MtnTrucker
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Randy,the new master cylinder you bought was it for a front disc set up? 75 and up....would have it been easier to buy a 74 MC and just take the residual valve out...so you wouldnt have to mess with the rod 
Randy,the new master cylinder you bought was it for a front disc set up? 75 and up....would have it been easier to buy a 74 MC and just take the residual valve out...so you wouldnt have to mess with the rod
iirc, he got a mini truck one from jcrapo
solution
Just glad you got it solved without changing a bunch of parts first!
Just glad you got it solved without changing a bunch of parts first!
I found a tip somewhere (I think it was here on Mud) to check your final length on the MC to booster rod. This is after you have confirmed that the rod is close to correct length.
1. set your booster on your workbench with the firewall side down on the bench top. Put the booster to MC rod in place in the booster. The rod will be standing upright now.
2. Take your MC, turn it over so you are looking at the socket the MC to booster rod fits into, use a Q-tip (or some other small tipped device) dipped into grease, not too much, put the grease into the very bottom of the socket so there is about 1/16th inch thick layer on the bottom only, again not too much or this will not work.
3. Now, turn the MC over and very carefully place the MC down onto the booster. The MC should set tight to the booster without forcing it. Next, carefully lift the MC straight up being surel not to bump the rod on anything. If the rod has a small amount of grease on the tip only you are set to go. I don't remember what the exact clearance of rod to MC socket is supposed to be but it is only a few thousanths of an inch. When the grease is only on the tip of the rod you have your correct clearance.
Good luck!
Don
1. set your booster on your workbench with the firewall side down on the bench top. Put the booster to MC rod in place in the booster. The rod will be standing upright now.
2. Take your MC, turn it over so you are looking at the socket the MC to booster rod fits into, use a Q-tip (or some other small tipped device) dipped into grease, not too much, put the grease into the very bottom of the socket so there is about 1/16th inch thick layer on the bottom only, again not too much or this will not work.
3. Now, turn the MC over and very carefully place the MC down onto the booster. The MC should set tight to the booster without forcing it. Next, carefully lift the MC straight up being surel not to bump the rod on anything. If the rod has a small amount of grease on the tip only you are set to go. I don't remember what the exact clearance of rod to MC socket is supposed to be but it is only a few thousanths of an inch. When the grease is only on the tip of the rod you have your correct clearance.
Good luck!
Don
- Thread starter
- #26
Randy,the new master cylinder you bought was it for a front disc set up? 75 and up....would have it been easier to buy a 74 MC and just take the residual valve out...so you wouldnt have to mess with the rod
The main reason for going with the new, late model truck MC is because it has either a 1" or 1 1/16" diamter bore so it moves a lot more fluid than a stock 74 version would. As I understand that helps improve braking response and lowers the pedal effort required to activate the brakes firmly, gives you a firmer pedal I guess. Since it was intended for a later model truck with discs front/rear from the factory it didnt have any residual valves in it. All my issues were due to the rod length being 1/4" longer than required even after the adjuster was cranked all the way in.
I ground that puppy off and it's amazing, my old F engine can get me up hills now with no effort that required down shifting before. I'll bet my gas mileage is better now too
................
