I just bought my first Pontiac, a '60 Bonneville Vista. I will have a bunch of questions as I get it in shape for the road after being idle for about 25 years.

The master cylinder is corroded beyond honing, so it needs replaced. Apparently, two boosters were used- Moraine and Bendix- each using a different MC. I have the booster off and can find no markings as to manufacturer. The MC has a part number 298026. Receipts I got with the car indicate the MC was replaced and the booster rebuilt a year before it came off the road, so it isn't the original MC.

Since it was driven only a few miles after the last brake work was done and then it sat for 25 years, I did not even try to use the brakes. I am concerned about a possibility that the current MC and the booster are not the right match and may not work right if I buy the same MC.

I can provide pics of the MC and booster if it would help someone identify the booster and confirm the match. Any input is greatly appreciated.

Thanks,

Charlie

Hello Charlie,

As long as the master cylinder is not cracked or overtly damaged, the bore can be sleeved and repaired.

Head over to the following site and see if you can cross reference your MC and booster:

Brake Materials And Parts

Brake Parts, Brake Relining, Booster Rebuilding, Brake Ho...

We provide the highest quality brake parts, brake relining, and booster rebuilding services. Specializing in restoration and hard-to-find brake parts. Custom length brake hoses and brake lines with...

This company in Fort Wayne, Indiana rebuilt my booster when there were none to be found.

Edit: This company does not have pictures of reference master cylinders so yes, please post a few pictures here. But they certainly can rebuild your MC.

Rick

Charlie, Rick is correct, but I would go one better! You really don't need to sleeve the master cylinder. Just bore it to the next size up piston & buy the piston parts. With the system being a power system any increase in effort for the increased capacity of fluid will be negligible. The increased fluid capacity will only improve the braking.

If you are unfamiliar with brake design & the math that will tell you exactly what what you need or what you have it is fairly straight forward. I thought I had posted up a document that walks you through it a while back, but I don't see it right now. If I can't find it on here I will post it up and let you know.

Thanks Rick, Gary. If I assume the MC is the correct one, I lean to having it sleeved. I have had better luck with brass than stainless sleeves. I have used Apple Hydraulics in NY state in the past, but may check with the guys in Ft. Wayne.

Hi Charlie

I would justA buy a brand new ms off Rock auto , they are cheap as chips mate 👍

https://www.rockauto.com/en/catalog/pontiac,1960,bonneville,6.4l+389cid+v8,1350919,brake+&+wheel+hub,master+cylinder,1836

Edited July 20, 2025Jul 20 by 64 kiwi boni