Check the check valve - AR43.10-P-0023GZ

MODEL 164 

Fig 1: Identifying Check Valve Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Shown on model 164.175 

	Check
1	Open engine hood		AR88.40-P-1000GZ
2	Connect vacuum tester (1) to brake booster (3).	Observe manufacturer's operating instructions to avoid erroneous measurements and incorrect operation. Reduce vacuum of brake pedal beforehand by pressing pedal several times.	AR43.10-P-0024-01GZ
		Test connection	Fig 2
		Vacuum tester	Fig 3
	Risk of accident  caused by vehicle starting off by itself when engine is running. Risk of injury  caused by contusions and burns when working in engine during starting procedure.	Secure vehicle to prevent it from moving. Wear closed and snug-fitting work clothes. Do not grasp hot or rotating parts.	AS00.00-Z-0005-01A
3	Start engine and create a vacuum of 0.75 to 0.80 bar by accelerating and then suddenly releasing the accelerator pedal.	If vacuum is > 0.8 bar, reduce vacuum to 0.75 to 0.80 bar by pressing pedal.
4	Switch off engine and observe measured value for vacuum at pressure gauge of vacuum tester.	Vacuum must not drop by more than 0.2 bar within 30 seconds. If the vacuum drop is > 0.2 bar, install new vacuum line with check valve. With notes on defective brake booster: ↓
		Check brake booster	AR43.10-P-0325GZ
5	Disconnect vacuum tester (1) from brake booster (3).		AR43.10-P-0024-01GZ
		Test connection	Fig 2
		Vacuum tester	Fig 3
6	Close engine hood		AR88.40-P-1000GZ

Fig 2: Identifying Test Connection (168 589 08 63 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Vacuum Tester (201 589 13 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.