Replacement GT6 master cylinder

[Dave the tram]

My late Mk 3 GT6 suffers from very slow leakage of fluid (silicon) from the master cylinder (0.75 bore) and always seems to have a little bit of air in the system - pedal comes up a little after a quick extra jab. I was going to replace the seals, but as I’m unsure of the condition of the bore I thought it might be best to fit a new cylinder, especially when I spotted these for about £35. I know from experience that a lot of aftermarket parts are substandard, and this might still be the case if I spent more on one from the big suppliers. Has anyone got experience of using these? 
https://www.ebay.co.uk/itm/143425077356?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&_trkparms=ispr=1&amdata=enc:13J8ZrbDsQBi2XHBVC7F4kQ1&customid=Cj0KCQjwr9m3BhDHARIsANut04aKbTzf7GmL02Hsl9PAGguEWZHMoSi2bvm4s73oLDYlb-kHSWbM1BoaAo-zEALw_wcB

[dougbgt6]

Dave,

I have a late GT6, I thought my master cylinder had a problem, I tried to find a new one, they are hen's teeth! If you have found one buy it!

Doug

 

[trigolf]

Hmm...

I'm not totally convinced that it's genuine Girling new old stock- if they are that rare. Demon Tweeks, for one, advertise very similar looking Master Cyls for a whole range of fitments.🤔

[johny]

2 hours ago, Dave the tram said:

My late Mk 3 GT6 suffers from very slow leakage of fluid (silicon) from the master cylinder (0.75 bore) and always seems to have a little bit of air in the system - pedal comes up a little after a quick extra jab. I was going to replace the seals, but as I’m unsure of the condition of the bore I thought it might be best to fit a new cylinder, especially when I spotted these for about £35. I know from experience that a lot of aftermarket parts are substandard, and this might still be the case if I spent more on one from the big suppliers. Has anyone got experience of using these? 
https://www.ebay.co.uk/itm/143425077356?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&_trkparms=ispr=1&amdata=enc:13J8ZrbDsQBi2XHBVC7F4kQ1&customid=Cj0KCQjwr9m3BhDHARIsANut04aKbTzf7GmL02Hsl9PAGguEWZHMoSi2bvm4s73oLDYlb-kHSWbM1BoaAo-zEALw_wcB

but thats got a tiny little reservoir much smaller than the your original Dave which is not good on brakes and says nothing about being 'Girling new old stock'. They are from early Land Rover clutch use (search part number STC500100) and come quite a bit cheaper than that but are sometimes advertised as being uprated for Triumphs with a corresponding increase in price. Ive got a cheapy one (12 pounds delivered) installed on my Vitesse brakes and it works very well but I have added a reservoir extender to give extra capacity....