commercial chassis master cylinder bore size

Aloha

Can anyone tell me the piston bore size on the 1962 Cadillac Commercial Chassis
master cylinder Delco Morain?

I need a spare as my 62 Eureka is a daily driver and I think it is starting to age. Passenger car is 1" and that won't work.

Can't find new or even a old core anywhere so thought I might send White Post Restorations a standard 1" bore one and have them bore oversize to 1.5" (if that is correct size) and put a brass sleeve in it.
Thank you
Rick

I ran out of time this morning. have to go to work. I think that the master cylinders are the same from standard series to 75/cc. I need to check the parts books when I get home.

Shoot me a pm so I dont forget.

The master cylinder is a 1" bore, and there are two different master cylinders listed for 1962, however, the book doesn't say what the difference is. I then checked another parts book, and it shows the same picture for both early and late 1962 master cylinders, and that the kit is the same for both, which leads me to believe that the difference is slight. It also shows that the "late" 1962 master cylinder is also used on the 1963 Commercial Chassis cars.
As for rebuilding, I strongly recommend that you consider Sierra Products for your rebuild. Aside from doing superior work, they are also much closer to you, being that they are located in California. Excellent work, and fast turn around. They also have the capability of repairing a damaged cylinder.

When in need of a service, please check our list in the forum called "Recommended Vendors".

http://www.brakecylinder.com

joe@brakecylinder.com

Sierra Specialty Automotive

3494 Chandler Rd. Quincy, CA 95971
(800) 4-BRASS-1 or (530) 283-1886
FAX: (530) 283-4845

different bore size?

My brakes were poor very and had everything replaced some time ago and are better but still takes along way to stop. I measured my spare master (delco morain) master cylinder and it is 1" bore so I suspect the one in my Eureka is also 1" bore. Maybe that the problem. Still have the wrong master cylinder. Please see below part of an old post regarding this. I think you may have posted this Paul? I know that rear wheel cylinders for 62 Commercial Chassis are larger so I would think you would need a larger bore master to push the fluid there. Thanks for input everyone. Rick



The master cylinder is also a Commercial Chassis only item, and once again, the parts books list this as being the same as the passenger car, however, the bore diameter is different. If yours is bad, then I would send that to Sierra Specialty also.
The brake booster is another item that is Commercial Chassis specific, and there is only one place that I would trust to rebuild this unit. I speak from experience. Most places that you might send the booster to, might just take yours and exchange it for one of there rebuilt units on the shelf. I remember going through this problem of incorrect booster and master cylinder with a person on the old website. It took almost 3 years until the person finally listened and sought out the correct parts for his hearse. His standard complaint was that the vehicle just wouldn't stop well, and his "mechanic" had replaced everything. What his mechanic did was to replace everything with incorrect parts, that would fit, but wouldn't perform properly.

Info

This from the 64 EIS catalog

M/Cyl

I bought this from a old school parts place a few years ago and by there application books it fit 62- 75 and CC. They had no computers only books and crusty help but good parts . It does have a a one inch bore.