Brake Issues
#1
Brake Issues
So im soon about to get my restoration on the road.
The brakes didnt feel strong so i bled them, and bench bled the master cylinder, i now have a firmer pedal with about 1-1.5 inch of movement on the pedal
(where before it would go to the floor with about 5inch of mmovement).
But stopping power is far from what id expect, i cant even lock them up with alot of pressure.
I turned off the engine pumped it a few times and it didnt get firmer of softer.
I held the pedal down with a little pressure and started the engine and it didnt sink any futher, i checked my power booster with a vac gauge and it held approx 12in hg for a while. and when i press the brake with the gauge still attached it drops to 0 immediately.
I do have vacuum going into the booster, and the one way valve is working as it should.
Any ideas?
The brakes didnt feel strong so i bled them, and bench bled the master cylinder, i now have a firmer pedal with about 1-1.5 inch of movement on the pedal
(where before it would go to the floor with about 5inch of mmovement).
But stopping power is far from what id expect, i cant even lock them up with alot of pressure.
I turned off the engine pumped it a few times and it didnt get firmer of softer.
I held the pedal down with a little pressure and started the engine and it didnt sink any futher, i checked my power booster with a vac gauge and it held approx 12in hg for a while. and when i press the brake with the gauge still attached it drops to 0 immediately.
I do have vacuum going into the booster, and the one way valve is working as it should.
Any ideas?
#2
Le Mans Master
Member Since: Jan 2006
Location: Boca Raton Florida
Posts: 9,192
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Bad booster most likely. Mide did the same thing when I got it. It would stop with a lot of pedal pressure but it took a while. If you stood on it it would stop a lil quicker but it was scary. Put in a new booster and refilled and bled and it would lock up like new.
#5
#6
m thinking that the valve that controls the air between the two chambers is faulty as vacuum is lost instantly as soon as the pedal is pressed, thus letting atmospheric air into the vacuum chamber???
Would i be right in assuming this is whats happening?
Would i be right in assuming this is whats happening?
#8
Race Director
See how much vacuum your engine produces. Anything lower than ~18" will give a proportionally harder pedal.
Here is a simple test.
http://www.mpbrakes.com/uploads/docu...tertestpdf.pdf
#9
Ok so i hooked up the gauge, and im only pulling 10in.... but it is fluctuating very fast between 8 and 12.
i have a .488 cam, if that makes any difference to such a low reading
i have a .488 cam, if that makes any difference to such a low reading