panalukes
Full Member
Guys, I got a weird one for you.
Background info: 77 with disc/disc from PO, weak braking force, pedal travel linear to braking force, not pulling to either side and I don't suspect caliper/slave cylinder issues, 33inch tires. I have bled the brakes multiple times. Bench bled the MC as well. I adjusted the booster plunger so that when it's at rest it's just shy of actuating the MC. Braking force is weak to the point that I can't lock up any wheel in a panic stop. With the engine off, the brake pedal is stiff. No vacuum leaks. Booster check valve works.
I suspected a bad vacuum booster and was able to swap mine out for another that a friend gave me.
With old booster I had weak brakes but it was pretty linear in the amount of pedal force, pedal travel, and stopping force.
Now with the new booster the pedal force for the first 2 inches is pinky pressure, then it gets stiff for the last inch. The braking force remains linear with pedal travel. So it's just a really "light" pedal for the first 2/3 of travel which makes it incredibly sensitive. And the last 3rd of travel feels like normal pressure. Overall braking effectiveness remains the same. Pedal feel is much different.
I suspect a bad MC.
Thanks guys.
Background info: 77 with disc/disc from PO, weak braking force, pedal travel linear to braking force, not pulling to either side and I don't suspect caliper/slave cylinder issues, 33inch tires. I have bled the brakes multiple times. Bench bled the MC as well. I adjusted the booster plunger so that when it's at rest it's just shy of actuating the MC. Braking force is weak to the point that I can't lock up any wheel in a panic stop. With the engine off, the brake pedal is stiff. No vacuum leaks. Booster check valve works.
I suspected a bad vacuum booster and was able to swap mine out for another that a friend gave me.
With old booster I had weak brakes but it was pretty linear in the amount of pedal force, pedal travel, and stopping force.
Now with the new booster the pedal force for the first 2 inches is pinky pressure, then it gets stiff for the last inch. The braking force remains linear with pedal travel. So it's just a really "light" pedal for the first 2/3 of travel which makes it incredibly sensitive. And the last 3rd of travel feels like normal pressure. Overall braking effectiveness remains the same. Pedal feel is much different.
I suspect a bad MC.
Thanks guys.
