my brake pedal has suddenly gone really hard I drove it a few yards and it seem to go back to normal, stopped again and within 5 secs it was hard again drove the car home and the pedal seemed fine till I pulled up home and the pedal went hard again, I’ve been told that I’ve probably got a crack in the brake vac pipe, and I’ve been told there’s a rubber upgraded pipe I can use, anyone else had this issue and did you upgrade the pipe, where did you get it and was it had to fit
thanks