The Stovebolt Site Forums The Shop Area The HiPo Shop I need to stop...........literally!

Still tinkering around with the rear end/disc brake swap for my truck. Finished up the emergency brakes recently and bled the brakes but I have no pedal pressure. I bled them twice now with no success. Any ideas on the cause?

Are you using the "cadillac" style callipers with the parking brake lever? You need to crank down on the parking brake to get the pads close to the discs. If not, all the pedal travel will go to move the pads close to the discs, and will not give you a firm pedal.

The calipers are from the 98-02 LS1 Camaro and the parking brake is a Lokar setup. Unfortunatey, this combo does not use the pads to set the brake but has a seperate system in place.

Where is the MC? Are you using any residual pressure valves?

Not knowing exactly what truck we are talking about, and what components used makes answering your question... well questionable. Give us the complete breakdown... 19** chevy */* ton with ***** axle using ***** brakes and a MC from a *****.

If you are using the stock master cylinder with late model piston calipers ,then you are running out of fluid in the MC before finishing the stroke.
The reservoir doesn't hold enough fluid for the caliper setup. You need a larger reservoir.

I believe it's the mc. I'd used a vaccuum pump to bleed the lines. Had my son the pump the pedal last night while I checked the bleeder and got nothing. I had changed master cylinders right before I started the rear end swap. It's the same type I had before (corvette style) that I swapped ou because I came across this one that had a proportioning valve already attached. It's a new unit that I got from someone who had purchased, then went another route. Can't swap the proportioning valve to the old mc because they use different size lines.

I have the same setup as you Robert and I am using an MC and booster from CPP http://www.classicperform.com/Store/1947_59_Trucks/4754BBD.htm
I don't have a problem with it.

So am I except mine is mounted to the firewall. Bought it new from someone who never used it. Not sure how long he had it laying around.

I agree that sounds like the problem.

I'm gonna play around with it tonight to see if I can figure it out. I may end up having to just go back to the old MC and install an inline proportioning valve for the rear.

Found the problem! I disconnected the MC from the booster and compared it to the other one I'd removed. The pin on the booster was too small and not making contact with the plunger when the pedal was depressed. I changed the screw and added a washer that was large enough to make contact to the plunger and the problem was solved.

Nothing better than solving a headscratcher. Now that you have solved your stopping problem you can concentrate on scooting.