Breaking Bias issue

[DSenga]

Hello,
Great to join this forum, I recently acquired FJ80, 1996 model. The unit looks great, engine runs smoothly, however, I have an issue with its breaking. It is biased to the rear wheels, which on 2 occasions has caused a spin on emergency breaking while at speeds above 50kmph.
We have done bleeding, checked for blockages, master cylinder looks ok, but still not sorted. The previous owner had deleted the proportional valve and no ABS.
Has anyone experienced this? How was it sorted

 

[FJ80HI]

My son has a 1990 Toyota pickup with solid axel swap and lifted 6 inches. We removed the proportional valve arm that went from axel to valve but left valve. Braking is great. I had a 79 fj40 and it did not have this valve and braking was fine. I thinking that valve might be in a bad valve setting if still in the brake system. Also read if the rear brake lines are failing. They can act as check valve leading to locked brakes. Have your recently installed brake pads? Could the rear drum surfaces be rusted? Did the truck sit for a long time where brake surfaces could be rusted pitted?

 

[DSenga]

My son has a 1990 Toyota pickup with solid axel swap and lifted 6 inches. We removed the proportional valve arm that went from axel to valve but left valve. Braking is great. I had a 79 fj40 and it did not have this valve and braking was fine. I thinking that valve might be in a bad valve setting if still in the brake system. Also read if the rear brake lines are failing. They can act as check valve leading to locked brakes. Have your recently installed brake pads? Could the rear drum surfaces be rusted? Did the truck sit for a long time where brake surfaces could be rusted pitted?

We cleared all lines to ensure that there is no blockage, no new brake pads. I'm also experiencing rear left tire brake disk overheating red hot, I looked the hand brake, but its still happening. This happens for sometime then stops. Not sure if the truck was in use before I bought it.
I'm planning to restore the proportional valve.

 

[Broski]

You really need to figure out why the rear breaks are sticking.
Did you grease the slide pins when you put the new pads in ? That’s the first thing I would check.
An adjustable proportional should work. I use a wilwood unit.
Right up buy the master cylinder.

 

[FJ80HI]

We cleared all lines to ensure that there is no blockage, no new brake pads. I'm also experiencing rear left tire brake disk overheating red hot, I looked the hand brake, but its still happening. This happens for sometime then stops. Not sure if the truck was in use before I bought it.
I'm planning to restore the proportional valve.

Drum brakes are finicky. When I replaced rear drum pads on my fj80 they rub for a while before braking in. Adjustment can be hard. A rusted drum just adds to the problem. Best to tear them down replace what needed and brake grease where needed