Front disc brake swap questions

[redhot67]

I need some advice on converting my power drum brake setup on my 67 C10 to front disc/rear drum. The plan is to go with dropped front spindles and buy a disc front kit, but after that’s where I’m getting confused. Do I have to change the master cylinder (no big deal and fairly cheap) or does a proportioning valve take care of balancing pressure using the existing master cylinder. On the other hand, if a disc brake MC is used, is a proportioning valve still needed? What about the power booster – do I have to change it? Any thoughts on the best kit, especially one that uses existing ball joints and tie rod ends (such as McGaughy’s) versus the kind that upgrades to later model 73-87 parts?

Thanks!

[jimmydean]

I used an aftermarket disc/drum prop valve with a power booster and MC off an all drum Suburban when I did mine.

The prop valve was a pain in the ass because I had do do some funky fittings to get everything hooked up.

[redhot67]

jimmydean,

Sounds like the valve should be all I need. Do you recall where you got it?

Thanks

[harleyx2]

i went to advance and had them pull to master cylinders. one for a 68 and one for a 72. the resovoirs for a drum drum setup on a 68 were the same size. the resovoirs for a 72 disc drum setup had a big resovoir and the other one was small. this tells me the master cylinders are different. although a friend of mines 72 with front disc has the same size resovoirs.

[jimmydean]

Originally Posted by redhot67

jimmydean,

Sounds like the valve should be all I need. Do you recall where you got it?

Thanks

I got mine off ebay and it was a pain because I didn't gt the right lines for it. CPP has one for $75 or something. Looks like this:



<edit> Also the fitting on the back is different for the rear line. I had to do a fitting to adapter to fitting to fitting. NAPA had everything I needed, but it looked Ghetto. Worked like a charm and was about $10 worth of brass and a 10" section of line.

[shade67]

I've always used the master and proportioning valve from a 73-80 chevy c-10 and haven't had any problems- I've always lucked out and found someone scrapping one and got the parts for almost nothing.

[harleyx2]

hey shade. what booster did you use?

[shade67]

Originally Posted by harleyx2

hey shade. what booster did you use?

I used a booster from a 87 C-10. My buddy used a 67-72 when he did his. almost any booster from a larger car will bolt to the 67-72 bracket. I've used Regul and Bonneville boosters with good luck before!

[redhot67]

Thanks for the help, y'all. I appreciate everyone's input.

[no moa]

Good info, I have a 77 blazer I'm going to use the PB from on my 71.
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[jim zag]

Drum brakes have a residual valve in the master under the fitting where the line fits in the side. Disc brakes will drag unless you remove it. Take a sheet metal screw and screw it into the brass seat and use two screwdrivers and carefully remove the seat and you will find a rubber disc and a small spring. Then push the brass seat back into place. Now your disc brakes will not drag.