S80 T6 Executive L6-2.8L Turbo VIN 90 B6284T (2001)
Check if there is a vacuum to the power brake booster. Do this by removing the hose from the check valve.
Depress the brake pedal several times to so that it has no travel.
Hold the pedal down. Start the engine. The pedal should travel and feel softer.
Release the brake. switch off the engine. Wait 1 minute. Then depress the pedal. The pedal should still feel soft but should become stiffer when it is
depressed several times.
Replace the power brake booster if the pedal feels hard and unresponsive when the engine is idling.
To replace the power brake booster on a left-hand drive car, see Power brake booster, replacing, L.H.D See: Service and Repair/Power Brake Booster,
Replacing, L.H.D.
To replace it on a right-hand drive car, see.