Checking brake booster - AR43.10-P-0325GG

MODEL 460, 461

MODEL 463 up to model year 2013 except CODE 979 (Special protection MB Guard)

MODIFICATION NOTES

4.1.02

Introduction of Brake Assist System (BAS) 30.09.01

Step 4

Fig 1: Checking Brake Booster

Courtesy of MERCEDES-BENZ USA

	Check
1	Connect vacuum tester (030) to brake booster		AR43.10-P-0024-01GG
	Measurement connection for checking non-return valve or brake booster	Only valid up to delivery date 31.12.1997.	WF58.50-P-4310-01A
		Vacuum tester	Fig 2
2	Connect pressure tester (051) to test connections.
	000 588 07 21 00 Test equipment		WS42.00-P-0014B
		On vehicles without test connections, connect the pressure tester (051) with the connection fitting to the brake caliper.
		Model 460, 461 Model 463 (except 463.270/271) up to model year 2013 except code 979 (Special protection MB Guard) Bleed screw at front axle fixed brake caliper	*BA42.10-P-1001-02B
		Model 463.270/271 up to model year 2013 except code 979 (Special protection MB Guard) Bleed screw to front axle floating brake caliper	*BA42.10-P-1001-03G
3	Attach pedal force meter (060) to brake pedal.
	000 588 05 21 00 Roller brake test stand		WS42.00-P-0006B
4	Start engine and by opening the throttle produce a vacuum of 0.6 to 0.8 bar.	If only a substantially lower vacuum is attained, or if the vacuum immediately falls away, the O-ring between the brake booster and the tandem master brake cylinder may be damaged or the check valve in the vacuum line may be defective.
		Brake line pressure	BE43.10-P-1003-01B
		The vacuum lines for the differential locks and vacuum reservoir may also be leaky. ↓ On vehicles with diesel engine, check vacuum pump. If air flow noises are audible at the brake booster: ↓
		Install new sealing ring of diaphragm travel sensor.
5	Apply specified force to the brake pedal and read line pressure	Brake line pressure	*BE43.10-P-1003-01B
6	Detach pedal force meter (060) from brake pedal.
7	Disconnect pressure tester (051) from test connections	On vehicles without test connections, disconnect the pressure tester (051) with the connection fitting from the brake caliper.
8	Disconnect vacuum tester (030) from brake booster
9	Bleed brake system	Model 460, 461, 463	AR42.10-P-0010GG
		Model 463.270/271	AR42.10-P-0010GX
		Only vehicles without test connections. Only bleed the brake caliper to which the pressure tester was connected.

PNEUMATIC BRAKE BOOSTER TEST SPECIFICATIONS

Number	Designation					Model 460, 461	Model 463
BE43.10-P-1003-01B	Brake line pressure	Intake manifold vacuum 0.6-0.8 bar	Force on brake pedal	50 N	bar	11...21	11...21
				100 N	bar	35...45	35...45
				150 N	bar	53...63	53...63
				200 N	bar	81...90	81...90
				250 N	bar	98...120	98...120

FRONT AXLE FIXED BRAKE CALIPER

Number	Designation		Model 460	Model 461, 463
BA42.10-P-1001-02B	Bleed screw at front axle fixed brake caliper	Nm	14	14

FRONT AXLE FLOATING BRAKE CALIPER

Number	Designation		Model 463.270/271
BA42.10-P-1001-03G	Bleed screw to front axle floating brake caliper	Nm	17

Fig 2: Identifying Vacuum Tester (201 589 13 21 00)

Courtesy of MERCEDES-BENZ USA