1972 Master cylinder

[Mike Bilger]

Can anyone please tell me the proper master cylinder for my 1972 small block with PS? I have seen casting numbers that differ in catalogues, some have bleeders some not, etc. I have had a failure of the non-stock replacement and want to get the car on the road. Eckler's claims they have a stock PG #5460346 master in their catalogue but...?? Thanks!

[Jack H.]

Re: 1972 Master cylinder

This info should be in your copy of the NCRS judging guide... The PS option has no effect on the brake master cylinder, the only issue is manual vs. power brakes.

The casting number for the master cylinder is 544409 for standard brake systems and 5480346 for power brakes. There WAS a running change associated with these MC's creating an early vs. late version of the part. Prior to 1974, the raw casting was drilled/tapped in secondary operations to add bleeder screws on the side and these were dropped for '74 and later cars. So, you want the early version of the MC to match your '72...

[Mike Bilger]

Re: 1972 Master cylinder

Thanks Jack! I have misplaced my judging manual which is why I went to this site and apparently misplaced my mind since I obviously meant PB NOT PS! The Eckler's catalogue gives a casting # 5460346 w/bleeders. A typo? And I guess I do need to have the bleeders. I have owned the car for 23 years bought from the original owner in Mass. It has been a great car and very competitive in NCCC shows. The storage has been tough on it and the wipers will now not work either. The door will open but the wipers will not move. Thanks again!

Mike

[Norm C.]

Re: 1972 Master cylinder

Corvette Stainless Steel Brakes supposedly has the cast mold for the dual bleeders, that others on this forum says is a very near perfect match to the originals.

[Joe L.]

Re: 1972 Master cylinder

Mike-----

I believe that the actual casting number for the PB master cylinder was 5460346. However, it often APPEARS as 5480346. If the third digit on any examples actually is an "8", then it's some sort of foundry error. I can find no record of any part number in the "548" series was ever used by Delco-Moraine.

[Jim T.]

Re: 1972 Master cylinder

Mike sometimes early C3 owners forget about the wiper control switch located at the bottom of the dash with the pull down vacuum switches. If the wiper control switch is on your wipers will not move.

[Mike Bilger]

Re: 1972 Master cylinder

Jim,

If not the control switch where might I go from there on diagnostics. Thanks.

Mike