HELP..... no brakes.

[Mopar vance]

I have a 72 rally, just installed front disc brakes. Problem is no pressure, do I need the 2 piece proportioning valve set up.

 

[Adam]

Hard to say with no info, or pics. Yes, you should have a proportioning valve for proper function, but you should still have pressure. Did you put in the correct master cylinder, is it correctly connected to the brake pedal or booster rod long enough; are the lines hooked up properly; did you bleed the brakes; are the calipers on the correct side; rubber hoses in good shape....

post some pics.

 

[Chryco Psycho]

72 would ave a 1 piece proportionin valve

 

[Mopar vance]

Does this set up look correct. From rear of master cylinder to top of valve for front disc, front of master cylinder to bottom of valve for rear brakes

 

[Chryco Psycho]

te front line from te master feeds te rear brakes & sould connect to te bottom of te proportionin valve , te rear line from te master feeds te front brakes left & rit at te top of te prop valve
It could be a 70 style proportionin valve , not 72 style .
I am missin letters between F & I bit I believe you can understand !!

 

[moparleo]

" No pressure" Does that mean that you have no pedal and it just goes to the floor, even after doing a proper bleeding of the master cylinder on the bench and then bleeding the entire brake system staring at the right rear wheel ?
Did you piece meal the conversion yourself or get the info from an article ? Or bought a conversion kit ? What are we working with ? What parts did you use ?
We need details. When you go to the Dr. and just say " I don't feel right " He is going to ask exactly what doesn't feel right and what does "feel right" mean?
Help us to help you.

 

[Mopar vance]

Factory booster, master cylinder, brake calipers. New lines, proportioning valve. Went from manual to power. Pump the hell out of the pedal ok, let off and too the floor. Don't see any bubbles when bleeding the lines

 

[Chryco Psycho]

Bleedin brakes you must pump slowly , you can aerate te fluid pumpin rapidly.
Are te calipers mounted correctly , te bleed screws must be at te top of te caliper mounted correctly so air is removed .

 

[Mopar vance]

Bleed screws located at the top. Would there be a difference between the manual and power brake push rod.

 

[Rapidfire]

Yes, the push rod is longer on power brakes!

 

[Mopar vance]

Does anyone have a measurement?

 

[Rapidfire]

I don't have an exact measurement as I have manual disc brakes, and my push rod is 7 1/4 so the power one will be longer. Mancini racing sells ajustable push rods!

 

[Mopar vance]

Thanks. Ill check all yhis out today. Muggy raining day in ohio.

 

[Chryco Psycho]

the pusrod is attached to the booster wit power brakes & uses a unique mechanism between the pedal & booster .

 

[moparleo]

Factory as in all Mopar parts for a 72 Challenger ? No specifics, good luck.

 

[Chryco Psycho]

picture of linkae

 

[Mopar vance]

Yes that's the set up

 

[fasjac]

The parts look good but, I would check the m/c bore size. I’ve seen this cause many headaches with barely having brakes to a cure for the problem by changing the m/c to the correct (usually smaller bore) cylinder. JMO

 

[Mopar vance]

Thanks for the info. Ad that to my list.

 

[retro70]

Also, make sure the distance from your booster rod end to the MC is only .020 inches apart.