Which booster/MC combo for disk/disk

[JMD]

I sat down to order a master cylinder/brake booster and realized there are a ton of options out there, turns out I'm not quite up to speed when it comes to brake systems, and a search here just got me more confused...

I'm working on a '67 K20 with disks all the way around ('75 K20 calipers and rotors on all four corners). I'm thinking I can use the stock booster, but which master cylinder should I get? What about a proportioning valve? Can someone please explain exactly what I should be looking for? Maybe dumb it down and use small words so I don't become even more confused...Thanks

[davepl]

Not an expert, but I'd get the stock setup form a '75 K20 and run that. Is there any reason not to? The factory paid some clever engineers to build it as a system and you've already got most of it.

Failing that a disc/disc master and prop valve from a late 60s Corvette has usually sufficed. Or you can use an aftermarket unit.

I'd strongly recommend using all the factory pieces from pushrod to pad.

[JMD]

Will a '75 MC bolt up to my '67? I agree that going with all matching parts would be ideal, but I'm not sure if they are compatible...

What if I just used a '67 K20 booster and MC, and then used an aftermarket proportioning valve?

[67 chevelle]

you need a valve like this
http://www.ebay.com/itm/Brass-Combin...EaIA9Q&vxp=mtr

suposedly , I have used a disc drum combo vale with disc's on all 4s before with no issues ,,, butt,,, there are always variables that may make that less than ideal for you

[kehstr]

if you really want brakes that will stop on a dime, put hydroboost in it

[JMD]

Originally Posted by 67 chevelle

you need a valve like this
http://www.ebay.com/itm/Brass-Combin...EaIA9Q&vxp=mtr

suposedly , I have used a disc drum combo vale with disc's on all 4s before with no issues ,,, butt,,, there are always variables that may make that less than ideal for you

Thanks, that's exactly what I ordered. Hopefully it works!

[csfields]

I went with a Wilwood 1 1/8" bore master cylinder, stock brake booster, right stuff disc / disc proportioning valve. All works great together on my 14" rotors.

[davepl]

Originally Posted by kehstr

if you really want brakes that will stop on a dime, put hydroboost in it

Honestly I tried that on a marginal system once, they're not magic. If you've got a giant cam and no vacuum they're the perfect solution, but there's not that much more assist than with a good vacuum booster, or that was my experience...

[kehstr]

Originally Posted by davepl

Honestly I tried that on a marginal system once, they're not magic. If you've got a giant cam and no vacuum they're the perfect solution, but there's not that much more assist than with a good vacuum booster, or that was my experience...

The thing i love most about hydroboost, is they always have pressure, vacuum brakes can be hit and miss depending on the rpms of the motor. If you can find the right vacuum booster they work good, but i have gotten sick of trying boosters, so sense i know hydroboost works i go with it.

[Billhilly]

As far as master cylinders go for disc/disc I have just finished an all new install in a 72 K2500 with stock front and Eldorado rear calipers. CPP sold me a 1" cylinder specifically for the job that I blindly installed and plumbed up. It gave me brakes, but a very long pedal (almost to the floor). After much discussion I swapped in a 1 1/8" cylinder and problem cured! So personally, there is no discussion. 1 1/8" gives you the volume you need for calipers. Calipers require more volume than wheel cylinders.... Oh, stock booster, Wilwood adjustable proportioning valve. Oh again, Thanks for nothing CPP!