I have been taking these cars apart since 1985 and have always seen the master cylinder stamped with a 17 or 19 at the neck of the twin cylinders. I was certain I had a 19 mm master cylinder because of the high pedal pressure required to stop. I figured the PO bought in to the larger master for a better feeling brakes. So, I pulled off the front pan cover and found an unknown master cylinder.

1
3 With a circle around it

2
0
This is down the length of the barrel. Everything looks just like stock 914. I am thinking it is a BMW or a MB master cylinder. I think the number 20 on the bottom by itself is the diameter of the cylinder. If it is a 20mm I can use on the 914-6 suspension up grade with the bigger brakes.

Any thoughts?

Look for more numbers on the top side. You'll need a mirror or two.

--DD

Got the mirrors out and looked over the top. No markings of any kind. As you can tell this master cylinder has been on there awhile. It has got me baffled.

A search for 132 G comes up as a possible MB unit ...

My car is running a 23mm MB unit, but looks different than that.