66 brake question

[chemlab]

uhh so i have my 66 gmc that has power drums and i want to upgrade my master to a dual. guess the question is, will one from a 70 or so work or is
there a certain one i should go with? also will there be any mods i need to
know of ahead of time?

[TxRat]

You need to make sure the bore size is the same, You might start with one of these as the 68 vette master cylinder is one that most booster/master combos come with..

http://www.oreillyauto.com/site/c/se...968&vi=1040881

[Captainfab]

I would use a master cylinder and booster for a '67-'70 C10. You can use just the master cylinder if your current booster has the long intermediate pushrod.

The Corvette master cylinders are typically used on 4 wheel disc brake systems.....that's what the Corvette's had.

[luvbowties]

Hey, chemlab, when I added power booster & split lines to my 4w-drum system, I tried 1st with the same bore, 1-inch, and later experimented with one from like a 1967-1969 3/4-ton with 1 1/8-inch bore and manual brakes, since I now had power from booster to help with the pushing. It gave more juice per pump and made the pedal feel waaaay better. Since the cost on a remanufactured one from Cardone(I think was the brand--I know I got it from AutoZone or Advance A/P or O'Reilly)was only about $16, I felt it was cheap enough to experiment.
Also, when I read how the rebuilt ones are done, with re-boring and sleeves, I'd think we should be safe with them. Mine's going on about 4 years now, and absolutely pleased with the larger bore--and the rebuilt one.
sam

[TxRat]

Originally Posted by Captainfab

I would use a master cylinder and booster for a '67-'70 C10. You can use just the master cylinder if your current booster has the long intermediate pushrod.

The Corvette master cylinders are typically used on 4 wheel disc brake systems.....that's what the Corvette's had.

Good point on the 67-70 booster.probably the best way to go...

I'm however running the vette master cylinder on my 57 Nomad with drum/drum with no problems. The front and back bowls are the same size and no external proportioning valve..

[ABX131]

I used the 68 Vette M/c and Booster I got from Autozone for around $100. My truck already had the proportioning valve. I had to fab up a bracket using Capt. Fabs as a template. I went with the Vette MC/Booster because I eventually want disk in the back, already have them up front. The biggest reason was the back of the booster has a threaded post to connect the pedal linkage. Once installed we just made a connecting rod that is threaded and connected with a turnbuckle making it adjustable for play in the pedal. Brakes work great.

[chemlab]

thanks for the info guys, back from my holiday so i'm gonna get on this now.

I would use a master cylinder and booster for a '67-'70 C10. You can use just the master cylinder if your current booster has the long intermediate pushrod.

The Corvette master cylinders are typically used on 4 wheel disc brake systems.....that's what the Corvette's had.

gonna try my current booster first, whats the length i'm looking for on the pushrod?

[Captainfab]

I don't have a specific length handy. If you remove the master cylinder and look at the intermediate pushrod, the short one will be just barely visable. The long one will be obviously protruding out of the booster.......maybe an inch or so.

Originally Posted by chemlab

thanks for the info guys, back from my holiday so i'm gonna get on this now.



gonna try my current booster first, whats the length i'm looking for on the pushrod?