Last edited Tue Jan 21, 2014, 08:44 PM - Edit history (1)
It goes in a small round cylinder on the firewall near the brake master cylinder.
I've owned Brit cars for decades, and they use natural rubber seals in their master, wheel, and clutch cylinders. If you add Dot3 brake fluid to the system, you'll turn those seals to jelly in a matter of weeks. Dot4 (not silicone) fluid is the only type acceptable for British cars. You can tell if the wrong fluid was added because Dot3 causes the fluid to turn from clear to a murky black as the rubber seals melt away.
Earlier posters are correct that your car has a hydraulic clutch and that being the likely problem, but they are wrong about it being cheaper to replace than rebuild on a British car. The master and slave cylinders are easily rebuilt with a $30 seal kit available from Moss Motors. All traces of Dot3 must be cleaned out of the system. The clutch slave cylinder is easily spotted and removed on the bell housing.
If you added Dot3 fluid to the brake system, you can soon expect a total pedal failure soon as well, but with so many wheel cylinders, it gets much pricier to purge & rebuild. Don't be afraid to attempt to rebuild a hydraulic cylinder on an MG, it mostly involves replacing the natural rubber O-rings and light honing with emery cloth. There are only two parts to each cylinder so assembly is a snap. I think instructions are included with a rebuild kit.
Once again, if you added Dot3 to the brake master, get it out now. Do not let that contaiminated fluid reach the four wheel cylinders. If you have any questions, I'll be glad to help.
Edit history
= new reply since forum marked as read