1970 C10 Brake Pressure Problems

[elorenzof]

Good Morning,

Since switching the front from drum to disc on Phyllis our 1970 C10, i have not been too happy with my brake pedal and or stopping. (low pedal, but yes she does stop). the truck originally came with a power booster and distribution block with the drum drum setup. I figured the Napa Master Cylinder / Power Booster combo i purchased were no weno so I opted to get a Classic Performance Master cylinder and Proportioning Valve and ditch the old distribution block used for drum/drum setups. Installed no problem. Going to bleed the brakes starting from the pass rear i have a mytivac brake bleeder thingamajig and it seemed to start out good with lots of air and brake fluid coming out. then it stopped bleeding. Still have suction but no brake fluid. Reservoir did not go down on brake fluid on the rear cavity. So it seems that i sucked all the brake fluid out of the line but i cant get brake fluid to come out of the rear bleeder valve. I dont see any fluid leaking from any of the lines either. I need to mention i did bench bleed the master cylinder before i put it on the truck. Is there something I am missing? Does the new proportioning valve need have something done to it too? I had my wiff do the brake pedal up / down while I opened the valve and closed the valve to bleed that way but nothing was coming out no air no fluid. If someone can please help i'd be greatly thankful.

[geezer#99]

To bleed the brakes you need to push in that black button (and keep it pushed in) on the front of the prop valve.
They make a tool for that but a piece of flat metal will work. Bend it into a 90 and attach it to that front mount bolt.

[elorenzof]

Originally Posted by geezer#99

To bleed the brakes you need to push in that black button (and keep it pushed in) on the front of the prop valve.
They make a tool for that but a piece of flat metal will work. Bend it into a 90 and attach it to that front mount bolt.

I was just looking into that and i will try it. Searching Google there is another forum that says that the black button has nothing to do with bleeding the brakes. I guess its worth a try? Thank you

[geezer#99]

It centres the piston inside.
Some times you can slam the pedal down hard to centre it.
Easier with the button.

[stsalvage]

Originally Posted by elorenzof

Good Morning,

Since switching the front from drum to disc on Phyllis our 1970 C10, i have not been too happy with my brake pedal and or stopping. (low pedal, but yes she does stop). the truck originally came with a power booster and distribution block with the drum drum setup. I figured the Napa Master Cylinder / Power Booster combo i purchased were no weno so I opted to get a Classic Performance Master cylinder and Proportioning Valve and ditch the old distribution block used for drum/drum setups. Installed no problem. Going to bleed the brakes starting from the pass rear i have a mytivac brake bleeder thingamajig and it seemed to start out good with lots of air and brake fluid coming out. then it stopped bleeding. Still have suction but no brake fluid. Reservoir did not go down on brake fluid on the rear cavity. So it seems that i sucked all the brake fluid out of the line but i cant get brake fluid to come out of the rear bleeder valve. I dont see any fluid leaking from any of the lines either. I need to mention i did bench bleed the master cylinder before i put it on the truck. Is there something I am missing? Does the new proportioning valve need have something done to it too? I had my wiff do the brake pedal up / down while I opened the valve and closed the valve to bleed that way but nothing was coming out no air no fluid. If someone can please help i'd be greatly thankful.

One question I have for your why are you running your Plug wires alongside your valve covers. you know that you can run your plug wires under your motor throw your front motor mounts.

If your Running HEI I even have a helper for that one If your running Ram Horns which I see that you're doing run these plug wires from 1973 Corvette cus in 1973 was the last year they use Ram horns on the Corvette. Here are some pics to help you make your engine compartment look Better plus the Factory did it this way from 1955

Have a look this is on my 1972 chevy truck Pull the end spark plug boot off use WD40 in and around the boot before and after you pull them off and put them back on