Master Brake Cylinder Casting 5460346
I am trying to prepare my 1970 Corvette for NCRS judging and want to restore my master brake cylinder (which I think is original) that has been stored for many years. The casting number is 5460346 and doesn't match the casting number 5480346 that is in the 1970-72 NCRS Judging Guide. Can someone tell me if I have the correct master cylinder and if so, a good restoration shop? I have had my car 36 years. Thank you.
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Re: Master Brake Cylinder Casting 5460346
Duane----
You have the correct master cylinder assuming your car has power brakes. 5460346 is the correct casting number for this application. With casting numbers, a "6" can easily be confused with an "8". That's what happened in this case and many folks believe the third character in this casting number is an "8". I'm virtually certain it's a "6", though. For ONE thing, I can find no record that ANY part number in the 548XXXX series was ever released. For another thing, as I have carefully examined the third digit under magnification, it appears much more like a "6" to me than an "8".In Appreciation of John Hinckley -
Re: Master Brake Cylinder Casting 5460346
Joe, thank you for your reply, I feel much better. My car does have PB and I am sure the casting number is a "6" instead of an"8". In fact, the number in question is exactly the same as the end digit "6". Do you think the NCRS Guide is in error? Do you know of a good repair shop as the casting will need re-boring because of pitting.Comment
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Re: Master Brake Cylinder Casting 5460346
Duane----
I believe it's in error. However, it's of no real consequence. I really don't think that anyone that shows up with a master cylinder with the last 3 digits of "346" is going to be "dinged" because someone thinks the third character of the complete casting number is a "6" and not an "8". If they say it should be an "8", simply say that's what it is.
There are many sources for master cylinder sleeving. Whitepost Restorations and Apple Hydraulics can do a brass sleeving. Stainless Steel Brakes Corp of Clarence, NY, Vette Brakes, and Lonestar Caliper can do aa stainless steel sleeving. Either type is fine for master cylinders.In Appreciation of John HinckleyComment
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Re: Master Brake Cylinder Casting 5460346
This subject has been brought up on the tech board for over five years, and is probably the subject of more than that number of threads. I have master cylinders that have the 5480346 casting number, and when examined under magnification the third number is definitely an 8. Previous threads have had reports of both numbers, with the reporters being sure of their number.
To the best of my knowledge no one has come forward with a GM print to solve this. Hans Norberg once had the brake master cylinder prints, but on his passing his records were not preserved. Since these master cylinders are now being reproduced, one would assume the vendor doing that has the prints. How about settling the debate?TerryComment
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