master cylinder replace or refurb?

[Psw1811]

Kev - I’m not sure which one I need to order! What do you mean by euro or us spec? I know they are both larger 19mm but which one? I have a 1973 2.0 us car. Paul

[914 KEV]

Kev - I’m not sure which one I need to order! What do you mean by euro or us spec? I know they are both larger 19mm but which one? I have a 1973 2.0 us car. Paul

The US spec 914 brake master cylinder had a brake warning switch fitted that if brake pressure failed it would trigger the flashing red brake warning light. (the same one as the handbrake when applied)
The Euro spec 914 didn’t have this warning switch.
Here in the UK you can fit either as it is not mandatory to have a warning light flitted to the master cylinder at the time of production of the 914.
Over the years the price between the two ATE versions of the brake master cylinder would go up and down and for a long time the one with the switch would be cheaper and now it is more expensive. I have noticed since my post the price has changed which varies with what special offers they are doing!
ATE - Ref: 03.2119-0881.3 is the US spec one with the warning switch.

I always replace the 17mm brake master cylinder with the 19mm.
It was an oversight by Volkswagen at the time in the late 60s not to increase the bore size when they started to fit disc brakes to their cars. Porsche changed from 17mm to 19mm from the 356C when they first fitted disc brakes instead of drum brakes to keep the same distance of foot pedal travel when the brakes were applied as there is more brake fluid to move inside a brake caliper than a brake piston on a drum brake; if piston bore size was not increased the foot pedal distance required would be more than on cars fitted with the drum brakes; in doing so a slight increase of foot pressure is required from the driver on the brake pedal.

From mid ‘72 Volkswagen changed from the 17mm to the 19mm on the 411 and 412 and then the beetle followed too. The 914-4 never changed from the 17mm, the 914-6 was fitted with the 19mm from day one.

[Psw1811]

Thanks Kev, great explanation. I was wondering if 19mm was the way to go? Decision made as still looks like a good price. P

[Robster]

Hi all, I have a 17mm us spec one. Came off a car that I did a 5 bolt wheel upgrade. It's been in my garage for a few years and needs a good spruce up, but worked when I took it off. Free to anyone passing (I live in Wokingham near Reading).

[Dean.s]

Good news on the cylinder. Not a spec of rust inside. Rebuild it is then. Just have to find a kit.

[Dean.s]

I ummed and aaah'd over this for a few days and my parts source has sourced me a brand new fte master cylinder so i'm going to fit that. The cylinder i took off will be wrapped an stored for future rebuild and use.

Hopefully fte is a good make and will be good for years to come.