1963 Master Cylinder Rebuild Kit

[Harry S.]

Mine started to leak out the backend so I started to look for a rebuild kit. Finding a Delco Moraine is now impossible (5461305). I called NAPA for their kit (393). The closest one to New Hampshire is in Wisconsin. I started to look for Raybestos MK393, again, hens teeth.

The message is, the kits, no matter who makes them are starting to dry up. Just an FYI if you might need one soon, buy it now.

[James W.]

Re: 1963 Master Cylinder Rebuild Kit

Thanks for the heads-up Harry. My '64 hasn't had a kit put in it since I sleeved it with SS back in 1994. Planned on going through the entire brake system next spring before I drive it again, will start hunting one up now.


Regards,

James West

[Larry M.]

Re: 1963 Master Cylinder Rebuild Kit

Be careful who you buy from........especially if you use DOT 5 fluid (silicone). You definitely want parts made of EPDM rubber (EPR family). Other elastomers may or may not work. The other elastomer that MIGHT work is SBR.........which is frequently used past and present. But I am now thinking that it might have changed a bit over the years, and is now part of the DOT 5 compatibility issue we are experiencing from some suppliers.

EPDM is specified as totally compatible for all DOT 3/4/5 brake fluids in the Parker O-ring Handbook (standard of the chemical industry for elastomers for decades).

If only using DOT 3/4 than SBR or EPDM should be fine.

FWIW.

Larry

[Tom D.]

Re: 1963 Master Cylinder Rebuild Kit

See my email message.
(NAPA master cylinder from 1987.)

[Tom D.]

Re: 1963 Master Cylinder Rebuild Kit

Larry: Didn't the formula for DOT 5 change in the last few years? Lonestar no longer takes back a leaking brake caliper "for that reason".

Be careful who you buy from........especially if you use DOT 5 fluid (silicone). You definitely want parts made of EPDM rubber (EPR family). Other elastomers may or may not work. The other elastomer that MIGHT work is SBR.........which is frequently used past and present. But I am now thinking that it might have changed a bit over the years, and is now part of the DOT 5 compatibility issue we are experiencing from some suppliers.

EPDM is specified as totally compatible for all DOT 3/4/5 brake fluids in the Parker O-ring Handbook (standard of the chemical industry for elastomers for decades).

If only using DOT 3/4 than SBR or EPDM should be fine.

FWIW.

Larry

[Patrick B.]

Re: 1963 Master Cylinder Rebuild Kit

Larry: Didn't the formula for DOT 5 change in the last few years? Lonestar no longer takes back a leaking brake caliper "for that reason".

There is no evidence that the formulation of DOT 5 has changed. The Federal Motor Vehicle Safety Standard on brake fluid has not changed regarding DOT 5 fluid. A proposed change to test brake fluid with more kinds of rubber seal material was actually killed. More likely the rubber in Lone Star products has changed or Lone Star is unsure that the rubber has not changed and is covering its a** at no cost to itself.

The most recent Lone Star product I got was a resleeved master cylinder. Since I had a vintage Delco Moraine kit, I rebuilt my new master cylinder so I would not have to think about the Lone Star language. I have used the Lone Star O-ring type calipers with silicon brake fluid for about 3 years without an issue so far.

[Larry M.]

Re: 1963 Master Cylinder Rebuild Kit

Larry: Didn't the formula for DOT 5 change in the last few years? Lonestar no longer takes back a leaking brake caliper "for that reason".

[Joe R.]

Re: 1963 Master Cylinder Rebuild Kit

Harry,

Lone Star has the 63-64 rebuild kits LS110.

JR

[Michael J.]

Re: 1963 Master Cylinder Rebuild Kit

I bought up several of the dual circuit, Z06 master cylinder rebuild kits when I found one for sale a while back. Those are also unobtainium these days.

[Harry S.]

Re: 1963 Master Cylinder Rebuild Kit

Harry,

Lone Star has the 63-64 rebuild kits LS110.

JR

Thanks JR.

[Dan B.]

Re: 1963 Master Cylinder Rebuild Kit

Harry, if you do a search for "1963 Corvette master cylinder kit" without searching for any particular part number you will get many hits. They are still being manufactured, but in some instances under other part numbers now. The 7/8 bore kits fit many other cars as well.