Stress cracks of manufacturing origin can form on the vacuum hose leading to the brake servo, around the connections. The symptom is a brake pedal that becomes harder and a longer stopping distance.
What to check
- With the engine off press the brake pedal several times, then start it: the pedal should sink
- While driving watch whether braking needs unusually high effort
- Go over the vacuum hose at the connections: cracks, hardened rubber