72457 - F12 BRAKE PEDAL HARDENING

When the brake pedal is pressed there is a hardening in the pedal travel;No faults relating to the malfunction of the electric parking brake are signalled.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner diagnostic equipment to the diagnostic connector check the following at the Parking Assistance Node (N.B.A.):in errors ambient that there are no faults	Move on to Step	Presence of faults	Continue following the instructions in the diagnostic table
1	BRAKE SERVO SYSTEM OPERATIONAL CHECKS	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the operation of the brake servo system    Continue following the instructions in the test 3330DA Brake servo operational check	Move on to Step	Brake servo system operation faulty	Move on to Step
2	VACUUM PIPE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the vacuum pipe: there should be no bends or damage	Move on to Step	1. Pipe bent	1. Restore the correct geometry
			2. Pipe damaged	2. Replace the damaged pipe    See in Op. 3330D24 vacuum pipe for brake servo - r+r
3	SINGLE-ACTING VALVE CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the single-acting valve is working properly	Move on to Step	Faulty operation	Replace the single-acting valve    See in Op. 3330D20 one-way valve for brake servo - r+r
4	BRAKE SERVO PNEUMATIC CIRCUIT CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
2.4 20 V,2.0 TB,2.0 TB	In particular, check: that there are no air leaks; that there is no seizing or hardening of the brake servo	Move on to Step	1. Brake servo leaks	1. Replace the brake servo    See in Op. 3330D04 BRAKE SERVO - R.R. - Includes separation from master cylinder (pump) - for versions with Adaptive Cruise Control (A.C.C.).
			2. Brake servo operation not smooth	2. Replace the brake servo    See in Op. 3330D04 BRAKE SERVO - R.R. - Includes separation from master cylinder (pump) - for versions with Adaptive Cruise Control (A.C.C.).
4	BRAKE SERVO PNEUMATIC CIRCUIT CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
2.4 JTD 10V	In particular, check: that there are no air leaks; that there is no seizing or hardening of the brake servo	Move on to Step	1. Brake servo leaks	1. Replace the brake servo/pump assembly    See in Op. 3330D02 BRAKE SERVO/BRAKE PUMP assembly - R.R.
			2. Brake servo operation not smooth	2. Replace the brake servo/pump assembly    See in Op. 3330D02 BRAKE SERVO/BRAKE PUMP assembly - R.R.
5	VACUUM CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
2.4 JTD 10V	Check that the vacuum unit is working properly    Continue following the instructions in the test 3330DB Vaccum unit operational check In certain usage conditions, low engine revs with excessive use of the brakes, the vacuum for operating the brake servo may not be sufficient with the consequent hardening of the brake pedal. There is no point in replacing the brake servo	Move on to Step	Vacuum unit faulty	Replace the vacuum unit    See in Op. 3330D30 vacuum pump - r+r
6	BRAKE PUMP CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check: that there is no seizing in the brake pump. that there is no seizing in the front brake calipers	Move on to Step	1. Pump seizing	1. Replace the brake pump    See in Op. 3330C14 MASTER CYLINDER (PUMP) - R.R. for versions with A.B.S.
			2. Front caliper seizing	2. Replace the front calipers    See in Op. 3310A32 FRONT BRAKE CALIPERS - R.R. - Includes bleeding air
7	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Test the vehicle before returning it to the customer, checking that the problem no longer exists. The test is essential because the braking system is one of the vehicle's safety systems.