Brake issues (4 Viewers)

[Russelld53]

Good afternoon. I have a1968 FJ40. I recently converted the front drum brakes to disc from a newer FJ40, calipers, and rotors are all new. I also covered to power brakes using all new parts from a later Toyota, all new. I replaced rear shoes, and 4 new rear wheel cylinders. I added a wilwood adjustable rear proportioning valve and a front and rear residual check valves at the master cylinder, 3 psi for the front and 10 psi for the rear. For the life of me I cannot get a good pedal. I have checked and no leaks, but can pump the pedal once or twice and get a pedal. And the push rod at the master and pedal are adjusted correctly. Beyond frustrating. Any suggestions?

 

[pb4ugo]

Theres a ton of threads on this issue. Here's something I posted a while ago.
Post in thread 'FJ40 brakes are kicking my ass!!' FJ40 brakes are kicking my ass!! - https://forum.ih8mud.com/threads/fj40-brakes-are-kicking-my-ass.1334219/post-15395109

 

[charliemeyer007]

Bleeding the system isn't always easy. Bench bleeding the master is a good start. I like my Mighty Vac one man brake bleeder - how ever the makers of replacement wheel cylinders thread the bleed nipple poorly and I have to put Aviation Permatex on the threads in order to successfully vacuum bleed the system. Without the sealant it just sucks air in around the threads. If you have a person in the cab working the pedal, no problem.

Second - they mill the slot in the adjuster straight across instead of on a slant that will help keep the shoes centered.

Drive the rig slowly around, jam on the brakes hard several times, then drive again slowly for 50 feet with the brakes on and let the disk, drums, shoes mark themselves - so you can what is going on.

 

[Mark Jennings]

What master cylinder from what later Toyota? Some of those already include proportioning valves that don’t mix and match well with additional residual and proportion components.