Front brake master cylinder piston

[Mike Derrett]

Talk about dumb....
Stripping down the front master cyclinder it was so corroded that I had to drill a hole in the other end to force out the pistion and cup assembly. Fixed that OK (tapped the hole and inserted a bolt with a copper sealing washer, wouldn't even known it wasn't meant to be there after a coat of paint)
BUT, I was so excited in getting it out that I forgot to take a photo of how the cup seals went in place and the manual doesn't clearly show it.

Is this right ? The part I am concerned about is the chevron seal half way up the piston shaft. Did I get it the right way round or is it backwards?

(80 GS1000S, same master cylinder as an ET model according to my manual, the one with the rectangular master cylinder)

Thanks in advance, and I promise to take photos from now on.

[Nessism]

That looks right but I don't remember that loose seal on the end. Does it fit down into a groove in the metal piece?

BTW, basscliff has the 1980 GS1000 service manual supplement that has some good photos on this type master starting on page 54. Well worth the time to download... http://members.dslextreme.com/users/bikecliff/

[Mike Derrett]

Master cylinder question

Mr Nessisim,

Thank you for the tip, I ended up downloading the 80 GS1100 manual. Same brakes and better photos but still no answer. The seal is definitely there but still not clear on which way round. I think it nestles into the back of the main seal part (with the o-ring) but i'm not sure.

Best regards
Mike