Remove/install BAS diaphragm travel sensor - AR42.31-P-6002RT

MODEL 251 

Fig 1: Identifying BAS Diaphragm Travel Sensor Remove/Install Components

Courtesy of MERCEDES-BENZ USA

MODIFICATION NOTES

1.9.10

"Perform brake test on test bench" reference changed

Test sequence augmented/revised

	Remove/install
1	Release vacuum in BAS brake booster	The diaphragm travel sensor sealing ring may be sucked into the brake booster if vacuum is present. If this is the case the brake booster must be replaced. Reduce vacuum by depressing the brake pedal several times.
2	Open engine hood and raise to vertical position		AR88.40-P-1000RT
3	Unclip water drain pipe (1)	Make sure that the water drain pipe (1) is seated correctly.
4	Remove bolt (2)
5	Remove bolt (3)
6	Unscrew nuts (4)
7	Lift up cover (5)
8	Remove bracket (6)
9	Disconnect electrical connector (7) from BAS diaphragm travel sensor (9)
10	Lift circlip (8) and pull BAS diaphragm travel sensor (9) out of the brake booster (10) (arrow B)	In order to prevent a permanent set of the circlip (8), lift the circlip (8) by a maximum of 10 mm Use a suitable tool e.g. an angled scriber (arrow A). Coat liquid lubricant on the BAS diaphragm travel sensor (9) at the front. Install new O-ring (11). Installation:  Check and ensure correct latching of the circlip (8) in the groove of the BAS diaphragm travel sensor (9) and brake booster (10).
		Lubricant paste	*BR00.45-Z-1002-06A
11	Install in the reverse order
12	Read out and erase the fault memory using Star Diagnosis		AD00.00-P-2000-04A
	Risk of death  caused by limbs being caught  or crushed  by rotating parts when performing tests on the brake test stand	Never leave the vehicle unattended on the rollers except in an emergency. Ensure that no one is under the vehicle or near rotating parts during testing. In case of emergency, use the EMERGENCY STOP switch to shut down test stand.	AS42.00-Z-0001-01A
13	Carry out brake test on the test stand		AP42.00-P-4290BA

REPAIR MATERIALS

Number	Designation	Order number
BR00.45-Z-1002-06A	Lubricating paste, rubber parts 2.5 kg, DB supply specification 6867.00	A 000 989 01 60