Full Version: The Mystery 911 20.5mm Master Cylinder
About 2 years ago, I started working on the 75 Orange car. I knew I had a larger than stock master cylinder because of the high pedal pressure. It had the number 20 on it instead of 19. I posted on the the forum and no one had ever seen one. Speculation was it was from a BMW or perhaps a Mercedes. Well, today I was reading UP-fixin der Porsche Vol IV and came across an article about 1969 911 brakes. The article stated that there was a 20.5mm master cylinder. It was only used for the one year or less when it was replaced by the 19.5mm. The part number for it is 901.355.012.04 or ATE 3.2120-3901.3. I love it when I can solve a mystery.
QUOTE(914Sixer @ Jul 20 2017, 08:50 PM) 
About 2 years ago, I started working on the 75 Orange car. I knew I had a larger than stock master cylinder because of the high pedal pressure. It had the number 20 on it instead of 19. I posted on the the forum and no one had ever seen one. Speculation was it was from a BMW or perhaps a Mercedes. Well, today I was reading UP-fixin der Porsche Vol IV and came across an article about 1969 911 brakes. The article stated that there was a 20.5mm master cylinder. It was only used for the one year or less when it was replaced by the 19.5mm. The part number for it is 901.355.012.04 or ATE 3.2120-3901.3. I love it when I can solve a mystery.
Hey Mark
When I enter the part no. it switches over to 911 355 012 04
Is there a source ?
I have a '69 S
TIA
Rory
Rory,
I did not do any checking on the part. I was just excited about finding the answer.
I did not do any checking on the part. I was just excited about finding the answer.
Porsche often switches part numbers of little used parts to ones that are functionally the same.
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