Ok, Another Question RE Master Cylinders

[Chuck R.]

I have looked all over a power brake master cylinder off of a 69 and for the life of me cannot find any type of casting numbers at all!

This master cylinder is pretty rough and I have noticed a line indentations on the very bottom of the master cylinder body. Was these indentations the numbers?

F.Y.I. it has front and rear chamber bleeders

Just curious again.

Chuck 32205

[Terry M.]

Re: Ok, Another Question RE Master Cylinders *TL*

Chuck,
On original 1967-1973 (and maybe newer, but I am not sure) master cylinders the casting numbers are on the inboard side, as the master cylinder is installed on the car. Some years ago there was a story about 1967 and newer (up to about 1973-74) master cylinders, complete with the engineering drawing, in The Restorer.

[Chuck R.]

Re: This Things Got Me Swinging!

This puppy is bare as bare can be casting number wise.

All I can figure is that it might be an after market rouge replacement.

Thanks for your input Terry,

Chuck

[Mike M.]

Re: This Things Got Me Swinging!

IVE SEEN AFTERMARKET GENERIC MASTER CYL SOR 67 VETS THAT HAD NO CASTING #S ON THEM. napa ETC SUPPLIED EM.

[Joe L.]

Re: This Things Got Me Swinging!

Chuck-----

Every original 67-76 master cylinder that I've seen has the casting number and Delco logo cast on the right side (opposite the fitting side). Original 67 through 73 PRODUCTION and SERVICE master cylinders had bleeder valves. Later PRODUCTION and SERVICE master cylinders of the same casting numbers did not. The master cylinders available from Delco for the last 20 years are "generic" castings and have no Delco logo or GM casting number. Often, the right side of the master cylinder is cast with the words "Made in U.S.A."

Prior to about 1973, generic, aftermarket master cylinders were available which had the bleeder valves. So, just because a master cylinder has the bleeder valves does not mean that it is a Delco product. If it has the "Made in U.S.A." embossing, that's a tip-off, too. However, not all of these early aftermarket units had this.