Get better brake pedal when adding power brakes

[luvbowties]

We had a '64 c10 recently that someone had used rebuilt parts to install a power drum/drum brake system. Looked to be a fairly nice job & seemed all bases were covered--even had what we believed to be a Captainfab booster adapter, plus an adjustable proportioning valve on rear line, adjusted correctly by the way. Papers in the dash showed new wheel cylinders, we checked & they were correct for the truck; but NO papers on the power brake parts. The pedal just had too much travel to stop & didn't have the right 'feel'.

After several days head-banging and a couple hours bleeding all 4 wheels and adjusting the rears we had another theory:maybe it wasn't getting enough juice-per-pump. We looked at several online chains & finally found one site that gave specs for their mc's. We then found that a 1967 C20 WITH STANDARD DRUM BRAKES had one optional mc with a 1.125-inch bore; our '60-'66 all seem to have mc's with a 1.000-inch bore; and it bolted right on. This bigger bore mc did what the system needed; it provided a noticeably shorter travel and the right "feel". My partner & I both thought the inadequate brakes were at least partly why the po sold it to our customer so cheaply. And the rebuilt Fenco mc was less than $20. Sharing no $-interests in this company, it was A*TO-Z*NE that showed the bore-diameters. I'm sure others prolly sell the same thing, but I don't know what to ask for. Guess you could use a vernier cal. to measure the rear diam. of the mc-piston or bore?

We hope this helps save time and $ for other diy'ers--esp. us who love these old trucks.

[LostMy65]

Thanks for posting your issue and the solution you found.
My C20 66 power brakes stop me great, but the pedal did feel weird. I adjusted the push rod to engage the brakes sooner, and now they feel a lot better. But now you got me thinking that I need to double check what bore the Master Cylinder is. I just went to O'Rielly's and asked for a 1'ton MC for a 79 chevy truck. So yes, now I need to check the bore.
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[luvbowties]

Originally Posted by LostMy65

Thanks for posting your issue and the solution you found.
My C20 66 power brakes stop me great, but the pedal did feel weird. I adjusted the push rod to engage the brakes sooner, and now they feel a lot better. But now you got me thinking that I need to double check what bore the Master Cylinder is. I just went to O'Rielly's and asked for a 1'ton MC for a 79 chevy truck. So yes, now I need to check the bore.
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Wow! Bet it does stop good. Look at Autozone's selections for '79 one-ton pickup with NO filters other than just '79 1-ton pickup with 5.7 liter engine: 1.250-inch (NOT 1.125-inch!) and 1.312-inch bores...
http://www.autozone.com/autozone/par...mString=search

But, if i ain't broke...