or lack of.
take note that the people who say you should change the brake fluid are not just doing it to boost brake fluid sales. Also take note that if you overheat one front caliper on a disco I 'til it boils the fluid (assumed contaminated with water, I've never changed it on this motor) you lose ALL the brakes. (both circuits in both front calipers - checked this, actually: the manuals say that this only applies to pre-95 ones, 300-type have front-rear split. Dunno if that's infallibly true in practice. You can tell by how many brake pipes to each front caliper.
I think in this case it was a sticking caliper piston, 'cos initial symptoms were that it pulled to the right, the left brake being the hot one, so I reckon sticky caliper caused the overheat, followed by brake fade and then boiling the fluid.
once it cooled down they came back, but it was interesting while it lasted.
Happens I have some new calipers and vented discs about which didn't get fitted to a previous motor, so I'll put them on it, I reckon.