this is probabably a stupid question but just to make sure. the large bowl of the master cylinder that is closest to the firewall goes to the front brakes, and the front bowl has the residual pressure valve followed by the proportioning valve and then on to the rear brakes right?
It is backwards front to rear so easy to see how it can be mixed up. if that is right do you have a pressure gauge on the proportioning valve to see how much pressure is getting through the valve?
does it get better when you close the valve?
if it does not seem to change when the valve is closed then maybe the valve is defective. open the valve all the way make sure that the rear brakes lock worse than when it is closed, bleed the brakes again and make sure no dirt or debris is clogging the valve, and try adjusting it again.
also I assume you bench bled the master cylinder and have made sure the front brakes are bled well. I imagine you have already done all this stuff, but sometimes simple things get overlooked. if these things are all okay then you may have to try a lower residual pressure valve.
If I had to guess there is probably something simple wrong though. either a defective part in the kit or incompletely bled system, or a kink in a line somewhere
__________________ 65 mustang. supercharged 302 currie 9 inch, 5 speed.
65MYWAY
99 f150 extended cab 4x4 with kennebell supercharger |