I have a problem with my brakes which only happens occasionally when the car (CDT) is ticking over - like when I'm stopped at a junction or I've just started the engine...
The brake pedal goes very hard, with little movement and you have to press quite hard to get the brakes to work at all. Tickling the throttle makes it work OK. The brakes are fine once on the move. The problem only happens when the engine is idling. Basically, it's as though there is no servo assistance at low revs.
Is it a leaking vacuum pipe do you think? If so, is there a 'how to' anywhere which describes how to fix it.