Brake light switch leaking

[hanloncole]

OK fixed the brake lights, fitted new switch and bled all the brakes, the lights come on instatntly i press the pedal. Excellent. Only problem now is that brake fluid leaks from the brake light switch where it screws into the end of the master cylinder. I have screwed it in but not completely all the way as it is a really tight fit and i'm scared of busting something.
My question is: do these brake light switches have to be screwed all the way in so that the flange of the switch meets that of the master cylinder. How can i stop fluid leaking down the threads, can't really use PTFE tape?
Anyone got any similar experience, these switches are pretty reliable i believe so not may folks have to take them off and srew one back in.

Anyone??
Thanks
Simon

[Anonymous]

There should be a copper washer behind the switch.
MG

[hanloncole]

Thanks for the reply, No washer on ETKA parts catalogue, have you seen washers fitted between switch and master cylinder before?
Regards
Simon

[Anonymous]

Yes on lots of Aircooled and watercooled vw's.
MG