chuzie
Bronco Guru
- Joined
- Jul 21, 2006
- Messages
- 2,697
Hey yall.
I've had my '77 for about 8 years and from day one the braking action was marginal to nil.
It has discs in the front and drums in the back with a Duff's booster and 35" tires. Steel braided lines to the axles and hardlines in between.
I have to literally stand all my weight on the brake pedal to get this sucker to stop and this is to a somewhat of a coasting stop. There is no immediate or locking action whatsoever.
I replaced the rear shoes and adjusted them, replaced the front pads and calipers, replaced the master cylinder and even replaced the Duff's booster just in case. Nothing fixed the problem. I suspected the proportioing valve at one point so I eliminated it from the system, routed the front lines directly to the calipers and inserted a manual proportioning valve to the rears. Still no change. This was all about 7 years ago.
Until now I have just lived with it. I was recently at an ORV park and could not participate in a couple obstacles because of my piss poor brakes and that made me decide to finally fix the problem.
Reinstalled the old proportioning valve and am back to the way the system should be but with crappy brakes.
Couple of things I have done.
The MC I have is not a stock bronco MC. It seems to be slightly larger with a large reservoir in the rear and smaller one on the front. The ports are on the driver's side as well.
Bench bled the MC
Made sure I have good vacuum pressure and I can feel a difference with the truck on and off especially when bleeding.
The lines are well bled of air. (made sure to pull proportioning pin for bleeding fronts too)
The pedal is not spongy.
The pedal starts in the released position at 42 degrees and engages the pushrod at 45. Max resistance is at 50 degrees which is where I am standing on the pedal (still no effective braking action). Max pedal movement (to the floor with MC removed) is 65 degrees.
I know I have more potential movement in this system but something is stopping me. I have also adjusted the end of the pushrod and backed it in 1/16".
When bleeding the system I can physically move the pedal to the floor so it is not a physical blockage preventing movement.
Thoughts?
Please help a brother out. ;D
I've had my '77 for about 8 years and from day one the braking action was marginal to nil.
It has discs in the front and drums in the back with a Duff's booster and 35" tires. Steel braided lines to the axles and hardlines in between.
I have to literally stand all my weight on the brake pedal to get this sucker to stop and this is to a somewhat of a coasting stop. There is no immediate or locking action whatsoever.
I replaced the rear shoes and adjusted them, replaced the front pads and calipers, replaced the master cylinder and even replaced the Duff's booster just in case. Nothing fixed the problem. I suspected the proportioing valve at one point so I eliminated it from the system, routed the front lines directly to the calipers and inserted a manual proportioning valve to the rears. Still no change. This was all about 7 years ago.
Until now I have just lived with it. I was recently at an ORV park and could not participate in a couple obstacles because of my piss poor brakes and that made me decide to finally fix the problem.
Reinstalled the old proportioning valve and am back to the way the system should be but with crappy brakes.
Couple of things I have done.
The MC I have is not a stock bronco MC. It seems to be slightly larger with a large reservoir in the rear and smaller one on the front. The ports are on the driver's side as well.
Bench bled the MC
Made sure I have good vacuum pressure and I can feel a difference with the truck on and off especially when bleeding.
The lines are well bled of air. (made sure to pull proportioning pin for bleeding fronts too)
The pedal is not spongy.
The pedal starts in the released position at 42 degrees and engages the pushrod at 45. Max resistance is at 50 degrees which is where I am standing on the pedal (still no effective braking action). Max pedal movement (to the floor with MC removed) is 65 degrees.
I know I have more potential movement in this system but something is stopping me. I have also adjusted the end of the pushrod and backed it in 1/16".
When bleeding the system I can physically move the pedal to the floor so it is not a physical blockage preventing movement.
Thoughts?
Please help a brother out. ;D