View Full Version : fj40, brake nightmare

04-27-2012, 06:06 PM
I have a 1974 fj40 it has new front wheel cylinders, brake hoses, master and front shoes and the problem still has not been corrected. The peddle will pump up feel and hold fine but if you let off for even 15 seconds it will drop and only apply the rears. Any ideas?

04-27-2012, 07:14 PM
Sounds like they are still out of adjustment (or holding some air). Is the level dropping in the master? Did you bench bleed the master?

It's a pain to get all 4 drums dialed, but once they are, they work pretty well.

I think Jeff Zepp has a good write up somewhere. I used it when I did my brakes about 5 years ago and they have worked fine ever since. (except when my front axle seals leaked and soaked my front brakes in lube). :hill:

04-27-2012, 08:39 PM
Make sure you put the wheel cylinders in the proper position, they are handed and the bleeders need to be on the top.. This is easy to get mixed up.. Other than this, adjustment and bleeding.. Is the new master toyota? Do you have a FSM?

04-29-2012, 06:45 PM
I'm the last one you want giving you brake advise, just figured I would throw in that my 40's rear proportioning valve was bad. Caused the rear brakes to always lock up pretty violently even under moderate braking. I have front disks, so not sure if yours has the same factory proportioning valve under the master or not. Worth a look. I put in one from Jeg's, problem solved.

05-07-2012, 01:15 PM
There is no proportioning valve in an all-drum system like franktown99's. Hey franktown, I have a couple of questions for you, we'll see if we can get you headed in the right direction, OK?

Please elaborate when you write "pump up feel". What does that mean?

You wrote that it has a new master cylinder. Did you bench bleed it?

As PhatFJ wrote above the slave cylinders are all different, left top, left bottom, right top, right bottom. Are you 100% sure you installed them in their correct positions?

Good luck! When you've answered these questions, we'll have a better idea of what advice to give you.