Our 6 year old 1.8GDI Space Star has an intermittent brake problem.

Sometimes all four brakes lock on or the brake pedal sometimes becomes very sensitive. It is worse after being stuck in slow moving traffic for a while but can happen on the motorway as well.

Usually the result is a light juddering and loss of power but occasionally it can be quite severe. After parking up and allowing the car to cool down everything is OK.

Unfortunately the fault never happens when the car is with the garage for investigation.

Any ideas please?

regards.