# 1966 GTO Master Brake Cylinder with power assist



## Autie1969GTO (Mar 5, 2019)

I need a master cylinder w/power brakes (original drums all the way around) and when I look up for a 66 GTO (I have also looked up Buick/Chevy), I get multiple variations. The one that is currently on the vehicle that needs replacing has a 1" bore that's been on there for 23+ years. When I look them up some show for 64-65 only and not 66. Some have 1" bore and some have 7/8 bore. Some have different or multiple brake line opening/bleeder screw locations. My eyes are becoming blurred from looking. Any body w/a 66 have insight on what they have used for replacements that look original? I am staying with the original factory set up and do not want to convert to a dual cylinder or disc brakes.


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## GTOJUNIOR (Aug 7, 2011)

I went with the Raybestos MC36242 backed with the "Restoration" 9" Booster from Oldsparts.com, Yes Olds parts. This was on my '66 Lemans Sprint.
I can't find the spec on the MC but it fits all 1966 Pontiacs perfectly. 
It is a multi-port with bleed on top, while not 100% factory appearance it works for many apps.


















PONTIAC Raybestos MC36242 Raybestos PG Plus Professional Grade Brake Master Cylinders | Summit Racing


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OEM Delco Moraine Stamped Power Brake Booster 9" - OldsParts.com


Gold cadmium plated 9 inch booster comes with a vacuum check valve, two push rods for drum or disc brakes and the brake pedal clevis and pin. New Delco Moraine Power Brake Boosters are licensed by GM and Have Show Quality Iridescent Gold Cadmium Plating. Delco Moraine is Stamped on the face as...



www.oldsparts.com


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## Autie1969GTO (Mar 5, 2019)

GTOJUNIOR said:


> I went with the Raybestos MC36242 backed with the "Restoration" 9" Booster from Oldsparts.com, Yes Olds parts. This was on my '66 Lemans Sprint.
> I can't find the spec on the MC but it fits all 1966 Pontiacs perfectly.
> It is a multi-port with bleed on top, while not 100% factory appearance it works for many apps.
> 
> ...


Thank you!


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