Let me fist start off by saying im new to this board and car building so any help here is greatly appreciated...I have a 92 camaro and Im trying to delete the proportioning valve if possible and install a jegs ajustable one... So right now on the car i have a brand new stock master and power brake setup.... I removed the stock proportioning valve and in its place I installed a tee fitting that splits the rear resivior line too the right and left front brakes...

Then on the front resivior line I have a ajustable valve for the rear brakes tied inline..

This all worked in theory and the jegs tech agreed it should work too but it doesn't... I get barley anything going to the rear brakes after power bleeding them it wont hold the tires on jack stands just putting it in gear...

The only thing i can think of is that there is biasing built into the stock gm design of the master cyl.. I was thinking of connecting the front resivior line to the rear and having the jegs ajustable after that to control the rear pressure but not sure if that will work or if there is a replacement master cyl that sends equal pressure and flow at the same time to the front and rear?

anyone done this before?

 

there is no bias in the master cylinder.

is the pedal firm now?
did you bench bleed the mastercylinder?
what rear brakes do you have? disc or drum?
do you have good fluid flow to the rear brakes? if you crack the bleeder does anything come out?

have you changed the flex hoses in the rear? the one from the body and both to the calipers, if you have disc brakes? they tend to fail internally as they age and can block fluid flow

 

Yes the pedal is firm the brakes are a quick permormance disc brakes i bought thier 9" axle and brake kit the lines are braded steel on the axle and the flex lin was replaced with a braded steel one... Yes i get good fluid from the lines in the rear I'm thinking the problem is air still in the rear brakes I installed the calipers reverse and the bleeder is on the bottom and not the highest point of the caliper in the back.... oops.. so im thinking there is some air in the rear calipers.. what do you think?

 

I bench bleed the master and the rear was bleed with a suction gun then had a friend help using the old pump hold bleed method

 

Yes, there is for sure air in there. The bleeder screws cannot be on the bottom. It just lets fluid come out and no air. Switch the calipers and bleed again starting with the wheel farthest from the master cylinder.

 

Ok so i swapped the calipers today with the bleeders on the top still the same issue.... one thing i noticed that seemed wierd was when i have someone pump the pedal and i bleed the line right at the master for the front brakes alot of oil comes out and the pedal goes to the floor.... when i do the same thing to the rear brake portion not alot of oil comes out and the pedal does not floor... There has to be something inside different on between the front and rear portion of the master cyl...

or i didnt bench bleed it all the way and get the air out but still dont understand why the pedal doesnt go to the floor if i loosen the front resivior line for the back brakes