		TEST RESULTS
0	PRELIMINARY CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Carry out a road test to check in what circumstances the noise starts	Move on to Step 1	1. The noise is heard when braking 2. The noise is heard when steering	1. Move on to Step 1 2. Move on to Step 1
1	BRAKE SERVO VACUUM VALVE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the condition of the one-way valve on the brake servo vacuum pipe	End of diagnosis	Brake servo valve faulty	Replace the brake servo valve Op. 3330D20 SINGLE-ACTING VALVE FOR BRAKE SERVO - R+R

There is a low frequency noise coming from the engine, the intensity of which varies with the number of revs