/// Black brake fluid is a sympton of Dot3 contamination. There is a chemical reaction between Girling rubber brake seals and American Dot3 brake fluid. Check your calipers and see if they are Girling. The Girling logo is a capital "G". The cross member is a human forearm and the fist is gripping the rear curve of the "G". On front four piston calipers it is located between (above) the two input lines. This is a problem only with Girling parts. ATE or Bendix are not affected. Hoses not manufactured by Girling are not affected. Other washers such as in the combination box may be affected.

There have been ATE master cylinders for about $55 recently available. If you determine that you have this contamination problem flush the system or drain it before you start replacing parts. Do not allow any of the old fluid in the new parts. Stick to high grade Dot 4 and use "Approved by Girling" if available. Castrol GT LMA Dot 4 is what I use.