I'm Sorry, but I'm still confused about Power Brakes?

[jorgensensc]

I have manual brakes on my '68 now, with a wilwood adjustable proportioning valve since the front brakes have been converted to late model disc brakes.

I picked up a power drum brake setup off of a '67 c20 (dual diaphragm)with brackets.

It doesn't have a prop valve, but a distribution block since the truck came with drums all around, no need for the distribution block.

Now if I go to the parts store and get a master cylinder for a '71-'72 (for disc brakes) will it mount to the booster that I have? Or is there something funny about the rod inside the booster?

If it will work, do I need a traditional proportioning valve, or can I use my adjustable Wilwood Proportioning valve in place of the traditional style?

If someone tried to explain this to me before and i didn't understand, I apologize. For some reason even the search topics don't really explain it to me well enough. Just call me Box of Rocks! Thanks ahead of time!
Shawn

[pocoloco71]

I am going to try to help. I am certainly no expert. I dealt with master power
brakes to get most of my help and stuff. give them a call if this doesn't help
enough. Here goes. Power boosters don't care what mc they are hooked to.
But if that set up was from a c20 which is 3/4 ton. It most likely had a Delco
morraine (brand name) and half tons usually had Bendix. The way I usually
remember this is Bendix had double bails and d-morranine had a single far as
I know. Anyway the clevis rod in a half ton is too long to work with a 3/4 ton
booster cause I think its to long. But can get the short one from Master Power or whoever. So what I would do if your going to the parts store, take
the booster with you, and ask to see the delco morraine style mc. You just
need the holes to line up. As far as the proportioning valve question. You
have got to get proper pressure to each wheel. There are tools to measure
this. For the price of a proportioning valve, I think I would just get a disc
drum and be done. Unless you want to keep bleeding brakes trying the 2
you have. I hope this helps

[70c10]

Shawn, I used a 71' MC with my power drum booster and it worked fine. I got it at Autozone for $14 after turning the core in. I didn't have to shorten the rod.