GMC / Chevy Disc Brake Conversion

[oldbluechevy78]

I did a disc brake conversion on my FF14 bolt and have a few questions. I'm getting ready to bleed the system, but I've heard that i need a proportioning valve for the rear to adjust the pressure. I have also read somewhere that all you need to do is remove the line going to the rear brakes on the master cylinder and their is a little rubber stop in their that holds the pressure to the rear brakes, if you remove that you wont have the need for a proportioning valve. Is this true? The axel went under my 86 chevy blazer and all of the rest of the brake system is stock, i haven't changed anything yet.

 

[NOTATOY]

I have ran summit racing manual porportioning valves, they only run about $40?? Wilwood also makes one that is almost identical. They just have a knob to adjust, and easy to dial in.

 

[Chevycrew]

You would want to pull the check ball out of the master, and run a prop valve.

I have never removed the check ball.

 

[Anchor_Mtn]

the adjustable prop valves are easy to use and run about $40. You can also use a stock (non-adjustable) valve off of a late model truck that had a disc-disc setup from the factory.

 

[oldbluechevy78]

and you just splice this into the rear line anywhere, it doesn't mater where i guess. When you splice it in, will a double flare on the tubing work or do you need a 37 degree flare? Which side on the master cylinder has the check ball, and does this really need to be removed?

 

[Chevycrew]

I wouldnt worry about the master, just double flare and put in the prop valve in the rear line.

If you do want to mess with the master, remove rear brake line, remove insert, (I use a coarse wood screw, thread in and pull hard) the ball will be behind that. Then put the insert back (this is what the line seals to) and hook the line back up.

More often that not, I have taken them apart and found no check ball.

 

[oldbluechevy78]

guess I'll be ordering me a valve to put in then, thanks guys for your help!!! now i need to get out and go test my new axle.

 

[Erik d_lux]

I put in my prop valve a long time ago. I never really did spend the time dialing it in perfectly though until I positioned the valve inside the cab. now I can turn it while driving. Lots better than,... stab brakes, guess how it feels, turn valve, hope you went the right way, repeat....

 

[oldbluechevy78]

how hard was it to run it up into the cab?

 

[Erik d_lux]

Brake line is pretty easy to run. It all depends on how your system is routed now. You could always just cut your line, splice a loop to the cab/valve and return it to the same spot that you cut.

Here is where I put mine (on the side, just below the middle part of the console).

 

[oldbluechevy78]

Thats pretty cool, I'll have to look at my blazer and see if there is anywhere i can do that on mine