Had a loss of pressure, partial and straight down to the floor. Would build pressure back easily with one or two pumps, though lose pressure again moments later.
Thought it likely the small seal at rear of Master cylinder chamber had failed.
Obviously stopped using car. Next day I tried it and seemed fine, went for a couple of slow drives around the block, using the brakes a lot, though stopping at times for a bit as well, to see if they lost pressure.
Appears to be no loss of fluid. Thinking maybe seal hasn't failed, though maybe a bit of crud behind it at the time?.
Seals have been in there about 8 years (reluctant to change, as a matter of course, due to likely repro crap) and changed fluid 3 times in that period, (last time maybe 3 years ago).
So, if it is a bit of crud, maybe clean out Master Cylinder?, or any other advice would be great please.
Thanks, Dave