'63 master brake cylinder and '64-'67 power brake booster

[Ruud Z.]

I'd like to know if a '63 (non-power) master brake cylinder will fit onto a 64-67 power brake booster without
any modification ? Thanks Ruud

[Harry S.]

Re: '63 master brake cylinder and '64-'67 power brake booster

I believe it will. But the 63 P/B MC had a second bleeder port. It was on the engine side forward. You can have it drilled for the bleeder.

[Joe L.]

Re: '63 master brake cylinder and '64-'67 power brake booster

I'd like to know if a '63 (non-power) master brake cylinder will fit onto a 64-67 power brake booster without
any modification ? Thanks Ruud

Ruud-----


A 1963 master cylinder can be used on a 1964-67 power brake booster. The combination will not be "correct" but it will be functional. However, if you're talking about using this combination on a 1963 Corvette, I don't think that will work. It should work on a 1964 Corvette, though.

[Michael H.]

Re: '63 master brake cylinder and '64-'67 power brake booster

I don't remember for sure but I don't think a booster from a 64 will fit under the hood of a 63? The 64 booster is a larger diameter and a 64 hood has an area of the hood structure modified for clearance.

[Chris D.]

Re: '63 master brake cylinder and '64-'67 power brake booster

The later '64-up booster fits fine in my March built '63 driver. Been running around that way for a couple decades. A small, molded in clearance dimple exists in the hood support.

[Edward J.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Ruud, besure not to use the thumb screw cap retainer on the 63 master cylinder, It may contact the hood when shut. Use the power brake cap retainer screw ,Which is a hex head style.

[Michael H.]

Re: '63 master brake cylinder and '64-'67 power brake booster

The later '64-up booster fits fine in my March built '63 driver. Been running around that way for a couple decades. A small, molded in clearance dimple exists in the hood support.

Chris,

Now that I think about it, I believe you are correct. I remember a friend having some clearance issue on his 63 but it may have been because he also used a 67 master cyl and that's what probably caused the clearance problem.

[Chris D.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Michael,

I do recall a post some time ago about an attempted 67 master cyl update into an earlier car, the potential for hood damage, and the ever popular parting comment, "Don't ask me how I know."

[Joe L.]

Re: '63 master brake cylinder and '64-'67 power brake booster

All------


I can tell you this: the 1963-only power booster, GM #5462110, was discontinued without supercession in May, 1969. It was not replaced at that time for SERVICE by the 1964-only power booster GM #5464311. This strongly implies that for whatever reason, GM did not consider the 1964 booster to be an acceptable replacement for the 1963 booster. Does that mean that the 1964 booster is not usable for a 1963 application? No, it does not; it just means that for whatever reason GM did not consider it to be an acceptable replacement.

By the way, the 1964 booster, GM #5464311 was discontinued without supercession in February, 1972.

The 1965-E67 power brake booster, GM #5467011, was discontinued in October, 1967 and replaced by the L1967 booster, GM #5458832. The 5458832 was discontinued without supercession in November, 1979 and was never specified by GM in SERVICE for any 1963-64 application.

[Chris D.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Joe,

Any insights into the difference between the '64 and '65-E67 units? With dedicated part numbers for 63 and 64, and no back dated coverage for either one, it makes one wonder if there was a some design feature specific to drum brake operation. I've noticed no performance issues.

Six years seems to be an early sunset for a replacement part. Have you seen other examples of major items discontinued so soon?

[Joe L.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Joe,

Any insights into the difference between the '64 and '65-E67 units? With dedicated part numbers for 63 and 64, and no back dated coverage for either one, it makes one wonder if there was a some design feature specific to drum brake operation. I've noticed no performance issues.

Six years seems to be an early sunset for a replacement part. Have you seen other examples of major items discontinued so soon?

Chris------

I don't know what the differences were between them; I wish I did. However, as far as GM was concerned, there was definitely a difference in the drum versus disc brake boosters. In fact, the 1964 booster was also used for those 316 1965 Corvettes built with drum brakes and, as I previously mentioned, the 65-67 boosters were never specified for SERVICE of any drum brake Corvette applications. Can they be used? Well, possibly, but not with GM's blessing.

Six years is an EXTREMELY short period for the availability of a part, especially one critical to operation of a vehicle (things like interior trim parts often get discontinued well before 6 years but they are not critical to the operation of a vehicle). Can you imagine someone in 1969 finding out that they could no longer obtain a replacement brake booster for their 1963 Corvette? Of course, rebuilt boosters were available but not from GM. Also, GM sold rebuild parts for the 1963 booster well after the booster, itself, was discontinued.

[Chris D.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Joe,

Cruising the catalog for 64 specific booster components. Looks like most interals are common '64-'67 except group 4.901 cylinder assembly, pn 5464311 which is '64 only. That assembly is not specifically shown in the diagrams but I assume its the sleeve and piston components mounted to the diaphram that carry the pushrod force through the booster.

This would also control the force gain through the unit which very well could be taylored differently between the self-energizing drum brakes and the more linear disc system.

Either I was lucky enough to get a '64 only booster (doubtful) or the differences are small enough to not be debilitating. Either way, there's enough unknown here that the modification cannot be recommended for someone else to try without a better understanding of the components.

[Joe L.]

Re: '63 master brake cylinder and '64-'67 power brake booster

Joe,

Cruising the catalog for 64 specific booster components. Looks like most interals are common '64-'67 except group 4.901 cylinder assembly, pn 5464311 which is '64 only. That assembly is not specifically shown in the diagrams but I assume its the sleeve and piston components mounted to the diaphram that carry the pushrod force through the booster.

This would also control the force gain through the unit which very well could be taylored differently between the self-energizing drum brakes and the more linear disc system.

Either I was lucky enough to get a '64 only booster (doubtful) or the differences are small enough to not be debilitating. Either way, there's enough unknown here that the modification cannot be recommended for someone else to try without a better understanding of the components.

Chris------


The 5464311 is the complete 1964 booster assembly.

Glancing through the P&A Catalogs I note quite a few internal parts differences between the 1963 and 1964 assemblies. Also, there may be differences between non-SERVICED components of the assembly. Such parts are usually not required for booster rebuild/repair and are, thus, supplied only as part of the complete assembly.

Based on a somewhat quick review, it does appear that most of the component parts of the 1964 and 65-66 booster assemblies are the same. However, there must be some difference, perhaps concerning non-SERVICED parts.