Removing and installing BAS diaphragm travel sensor - AR42.31-P-6002A

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

MODEL 129, 140 as of 1.12.96, 170, 202 as of 1.6.97, 208, 210 as of 1.2.97

Shown on model 208

Fig 1: Identifying BAS Diaphragm Travel Sensor Components - Shown On Model 208

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Shown on model 210

Fig 2: Identifying BAS Diaphragm Travel Sensor Components - Shown On Model 210

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

MODIFICATION NOTES

1.8.99

Check diaphragm travel sensor for labeling

New parts are marked with a white, yellow or blue "D" (Fig 1 ). The label may be on the side away from you.

	Removing, installing
	Notes on brake booster		AH43.20-P-0001-01A
1	Operate brake pedal several times until vacuum in brake booster is reduced.	The diaphragm travel sensor sealing ring may be sucked into the brake booster if vacuum is present. If this happens, the brake booster must be replaced.
2	Unplug BAS diaphragm travel sensor connector (A7/7x1)
3	Remove locking ring (16b)	Use a suitable tool, e.g. angled scriber (arrow). Installation: Replace locking ring and ensure that it is correctly seated. Different manufacturers use different locking rings.
4	Pull out BAS diaphragm travel sensor (A7/7b1)	Installation: Rub a little spirit or soapy water onto the front of the diaphragm travel sensor so that O-ring slides correctly when inserted.
5	Replace O-ring	Installation: Insert O-ring into groove in brake booster and ensure that it is correctly seated.
6	Install in the reverse order
	Checking
7	Start engine	Operate brake several times.
8	Switch off engine
9	Check diaphragm travel sensor for leaks	There must not be any air flow noises audible at the brake booster.