The next step is to replace the old master cylinder. The 1972 Cutlass S is drum all the way around (restored drum and will be upgraded to disc in front). Original system did not have power booster. Would like to add power booster and correct master cylinder along with proportioning valve if required. Which setup is correct to work with drum setup for now and will also work with front disc upgrade in the future. Is this 1972 Cutlass specific or will different years and gm makes interchange.

 

Rick, welcome to the site! There's been a lot of discussion on this topic as it's a common upgrade. You can use the search option to find threads on the topic. But I'd read this one first if I were you. Joe put a lot of details into it and I think you'll find it helpful. John

https://classicoldsmobile.com/forums...sk-brakes.html

 

The master cylinders are completely different for all drum vs. disk/drum systems, so you cannot reuse that. The power booster will work with both master cylinders. The drum brake system does not use a proportioning valve and you should not install one at this time. Plumb it in when you convert to disks.

 

Since there is not a proportioning valve is the distribution block still required? Are parts 1972 Cutlass specific or will different years and gm makes interchange?

 

The distribution block should already be installed from the factory. It serves two purposes. First, it splits off the front brake lines to the front wheels. Second, it houses the differential pressure valve that illuminates the BRAKE light on the dash if you lose pressure in one end of the system due to a leak.

The drum brake parts are pretty much the same from 1967-1972. There are some minor differences in master cylinder piston diameter, and manual M/Cs have a different diameter from power M/Cs. All GM A-body cars from those years use common brake parts.

 

Thank you Joe. Started project in 2001 and removed distribution block at approximately that time. Was not my original plan to restore drum system. Finances halted the upgrade to disc/drum. The frame was the starting place for the restoration and I most likely threw out the the old block with no intention of reuse. Checked with local auto parts store and is not available. Any ideas in which direction to search for these parts as the power booster will be used in both setups, but the m/c and distribution block will not. Thanks again for previous information.

 

The dist block is not a normal wear item, so you won't find it at normal parts houses. Repros are available from the brake specialty houses like Master Power, but I suspect they are not cheap. Good used is your best option. People doing disc conversions usually just throw them away.

 

how do install the front disc converstion kit step by step or is there a web site i can go to. i have a 71 cutlass

 

dont try to run the disk master on the car if it still has drums. The P.O. had one installed on my 72 and the brakes really sucked on this car. you had to stand on the brake pedal to get the car to stop. worst set of brakes on any car I ever drove. the part is only $30 or so. run the drum master for now.

I understand the "going to swap" plan, but I have been "going to swap" to disk brakes for 15 years now......

 

Also of note- if you are converting from Manual brakes to power- you will need to change the MC's Pushrod location on the brake pedal.

There are two holes on the pedal arm- one is for manual brakes one is for power- I can never remember which is which, but just be sure to switch the positions on yours when you add the booster.