'56 GMC to Buick GN Master Cylinder

[greatdaen]

When I rebuilt my 56 GMC 1/2-ton several years back, I upgraded the brake system by means of an in line hydro-boost unit.

It works much better than just a stock master cylinder, but it is not ideal.

I plan to upgrade the system. I want to keep the master cylinder in the stock location. To get around the "real estate" problem of mounting under the cab, I picked up an electrically-boosted master cylinder out of a Buick Grand National. Has anyone used this unit? Problems? Lessons learned? Comments?

Thanks,

-dch

[DennyB]

Dan,
I'm not sure if this helps or even answers your question..
The brakes on the GN are less than ideal!
They fade away quickly at higher speeds and it would seem they would act the same way with a heavier/loaded truck.
I don't know if this is due to the master cylinder or the GNs having stock Regal brakes.

[greatdaen]

Denny,

Thanks for the input. I have never driven a Regal/GN so had no sense of their braking performance.

Granted my '56 is heavier. But I drive it for pleasure only so it never has a load in it.

I would suspect that the braking performance woes of the Buick are more related to the components at the wheels. Brake fade is usually an issue of wheel components heating up from absorbing braking energy.

I am still running the stock drum/drum setup on my rig. As part of the upgrade, I would like to go with disk/drum of even disk/disk. But before all of that, I am hoping that an apples-to-apples comparison of the Buick MC to my stock/hydro-boost MC shows the Buick is as good or better. Even if it just gives "same as" performance, I will be gaining a dual circuit MC for a little added safety, as well as the ability to meter the fluid seperately for a disk/drum setup.

Thanks again for the input. Keep those ideas coming. Its always better to learn from your mistakes than my own!

-dch