Discharge the vacuum in the brake servo, with the engine switched off, by repeatedly pressing and releasing the brake pedal forcefully.Start up the engine without accelerating, with the pedal depressed.After a few seconds, check that the brake pedal raises in accordance with the increase in pressure due to the action of the brake servo.Release the brake pedal and switch off the engine without operating the pedal again.After about 10 minutes with the engine switched off, operate the brake pedal and check the lowering corresponding to the brake servo when it is operated for the first time and that the operation becomes gradually stiffer when operated subsequently.