I did a search and didn't find a specific answer.
I bought a new front disc brake set around 1995 for a 66 chevelle that I had at that time.
One thing led to another and it never got used and has been sitting in my garage since then.
Can I use the master cylinder on a 4 wheel disc brake project I'm building?
It has the No. 29969 stamped in it and below that it says "Made in America"
The booster is marked "Delco Moraine". It is an 11" one. I plan on running hydro boost so that's not important.
Would I be better off selling the unit as is and buying one specific for 4 wheel discs?
Thanks for any info.
Kim

For a Delco master cylinder, the only difference between a 4 wheel drum, disc/drum, or 4 wheel disc master is the presence of residual pressure valves in the outlet port. They are located under the brass cones that are inserted into each output port and it is not possible to tell if they are there once the master is assembled. The residual pressure valves are for drum brakes. They maintain a low level of line pressure to minimize the pedal travel before the drums engage. If you use the residual pressure valves with disc brakes, the brakes will drag and wear down your pads. If your front disc package was a stock style front disc package, it most likely was intended for disc/drum in which case the rear outlet port would have a residual pressure valve in it. This would not be good for a 4 wheel disc package. Do you remember where you purchased the disc brakes? Some companies, like Master Power I believe, sell their kits with 4 wheel disc masters (no residual pressure valves) and then sell you an external residual pressure valve if you want to run rear drum. A web search for your casting number suggests that it is a corvette master (4 wheel disc), but I am not sure I would trust that. If you want to give it a shot, just install it and give it a try. If it is disc/drum, the rear brakes will likely drag a little and should engage a little quicker than normal.

Eric
Thanks for the info.
I purchased the front brakes from CPP.
It was a complete front disc set up with spindles and rotors. It was so long ago that I don't remember if I was going to go 4 wheel disc on the chevelle or not so it's possible I did get a disc/disc master.
Is it possible to remove the residual pressure valve if it has one?
Kim

I think you can remove the pressure valve, but I think you need to rebuild the master to do so. Try calling CPP and talking to them about. They might be able to tell you if they have sold any front disc kits with a disc/drum master. Otherwise, just take it down to NAPA and turn it in as a core for a rebuilt disc/disc one. Just ask for a master from a 1972 vette. Be sure to specify power (1 1/8" bore) or manual (1" bore) depending upon what you have. (Note: If you happen to be setting up C5, LS1, or similar brakes, you'll need a 1" bore if you run power brakes (so ask for 72 vette with manual brakes) and a 15/16" bore if you want to run manual (ask for '77 Chevy Malibu (with a six cylinder) manual brake master).

Thanks again Eric, I appreciate the info.
Kim