Disc Brake and master Cylinder

[Ralph140]

I put in a disc brake system out of a 77 fj55 into a 77 FJ40. I cannot lock up the disc brakes. I used my 72 stock master Cylinder and booster with the residual valve removed and a proportioning valve on the rear line.. I did a rebuild on the M/C, bench bled the M/C and bled and rebled the system and the problem persists. The rear brakes are working fine. Any ideas? Is there any stock toyota M/C tht will work with my 72 booster? Any suggestions on what else I might try or am missing?

 

[Ralph140]

booster M/C

I am too old for computers. I typed in that I did the exchange on a '77. My L/C is a 72 that I put the 77 brakes on. Sorry for any confusion. Help is still needed.
Thank you

 

[dgangle]

There are SOOOOOO many write ups/threads on this subject. It would probably benefit you to search, read a whole bunch and come back with more specific questions. There are many ways to skin a cat.

For example, an advanced search in the 40/55 section using "disc brake master cyclinder" yields IH8MUD™ Forums - Search Results

 

[Gotta40]

the 72 master is wrong one. its for drum/drum. need a disk one for proper volume. get the right one for the 77.

 

[mybluetoy]

Hey I did a brake conversion on a my 72 FJ40, I used parts from an 85 FJ60. I didn't change out my M/C.