brake light keeps coming on ????

[blackgti1.8]

That's because one of the circuits ran out of fluid. The brake fluid level indicators are a float that hangs off the cap with a plug on top.

If yours was built 9/80 it must be a private import or do you mean complianced 9/80?

Synchro's right - My '79 had two sensors in the master cylinder.
I gather it sensed differential pressure, though I never had a problem with
it coming on...

My '84 GTI OTOH, does have an electrical connection on the brake fluid filler
cap, not that it's connected to anything

Either you really do have a problem with a difference in pressure, or one
the sensors has failed...
Could be an internal seal leaking - do your rear brakes still work?

[jets]

Gine me the VIN / Chassis number and I will see what I can find out.

My chassis no is 17A0195671.
Thanks in advance.

[syncro]

Whoa! That's a genuine 1980! Built in November 1979. Rare as rocking horse ***** in Australia!

I've only ever seen one genuine Australian 1980 before.