Peugeot brake problem

[bigstraight6]

Learned colleagues, I have a strange brake problem with the sister in laws 1993 Peugeot 106 1.1, the brake pedal has suddenly started feeling very spongy, and if the brake pedal is continually pumped when the car is idling the engine then starts really rough running, any ideas?

[Station]

The inlet to servo pipe? The servo runs off the main vacuum that keeps the engine going. Either way, it's leaking vacuum. Listen for a hiss (if that's possible).

[Richard]

I think you might find the rough running when pumping the brake is normal. By putting a high demand on the servo you're affecting the manifold pressure, which could upset the fuel injection system- so I think you might only have one problem.Spongy brakes can have many causes. The most obvious is air in the system but it could also be badly adjusted rear brakes, damaged seals anywhere in the system or even play in the front wheel bearing (often caused by a loose driveshaft nut).Clamping each brake hose in turn might help to pinpoint the problem.