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Author Topic:   Brake question!
Dirt Maniac

Total posts: 102
posted March 09, 2005 08:07 PM  
I just got done installing a new master cylinder and went from vacuum assist brakes off of a 85 buick Reagal to a master cylinder off of a 75 Pontiac Ventura ( manual brakes - Front disc / rear drum ) and the problem is that the rear brakes will not bleed hardly at all. I had no problem with the front end and was wondering if my problems are with the proportioning valve. the pedal is very firm but still have no pressure in the back brakes. I bench bled the master cylinder prior to installing on my race car as per instructions. I would appreciate any help in regards to this situation. I've bled quite a few brakes over the years but this is a new one to me. The only thing I can think of is that I need to get rid of the proportioning valve. Thanks, Kent

Dirt Freak

Total posts: 402
posted March 09, 2005 09:39 PM  
There is a saftey valve in the combo valve that will slide over and block off flied to one side if there is a large pressure difference. Now is a good time to get rid of the valve anyway. The brakes will work much better without it.

Dirt Freak

Total posts: 474
posted March 09, 2005 09:44 PM  
for sure ditch the p valve and some drivers even reverse the front to rear lines to increase the rear brake bias. start you bleed at the m/cyl then follow your line back and crack every joint and make sure pressure is there before proceeding to the next. That especially means the rear rubber line. make sure the wh cyls are working. You
should rear brakes if all lines are free.
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make sure the m/cyl rod is the correct length or you'll never get rear brakes

[This message has been edited by bobaluuu (edited March 09, 2005).]


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