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

MODEL 205

MODIFICATION NOTES

28.4.14

Screw, lower strut to mounting bracket strut tower

BA62.30-P-1003-02K

Fig 1: Left Engine Compartment Paneling, BAS Brake Booster And Strut

Courtesy of MERCEDES-BENZ USA

Fig 2: Checking Brake Booster

Courtesy of MERCEDES-BENZ USA

	Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
	Risk of poisoning from swallowing brake fluid. Risk of injury from skin and eye contact with brake fluid	Only pour brake fluid into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.	AS42.50-Z-0001-01A
	Brake fluid notes		AH42.50-P-0001-01A
	Remove/install
1	Open engine hood and raise to vertical position
2	Remove left and right wiper arms		AR82.30-P-6100LW
3	Remove air-water duct at right and left (1) under the wiper arms
4	Remove strut (2)	Screw/bolt, lower strut to suspension strut tower mounting bracket	*BA62.30-P-1003-02K
4	Remove strut (2)	Screw/bolt, lower strut to firewall	*BA62.30-P-1004-02K
	Check
5	Eliminate vacuum in BAS brake booster (A7/7)	To do this, press the brake pedal several times with the engine switched off.
6	Connect vacuum tester (030) with test connection (031) to BAS brake booster (A7/7)		AR43.10-P-0024-01V
		Brake booster	*BE43.10-P-1001-01G
		Boost factor	*BE43.10-P-1002-01G
		Vacuum tester	Figure
		Test connection	Figure
7	Raise vehicle		AR00.60-P-1000LW
8	Detach front wheel and tire assembly	Model 205.086/087/286/287/386/387	AR40.10-P-1101A
9	Connect pressure tester (051) to brake caliper using connection fitting
	000 588 07 21 00 Test equipment		WS42.00-P-0014B
		Use correct connection fitting (pitch, cone etc.). Otherwise leaks and measurement errors can occur.
		Bleed screw on brake caliper	*BA42.10-P-1003-10W
10	Connect pedal force measuring instrument (060) at brake pedal
	000 588 05 21 00 Roller brake test stand		WS42.00-P-0006B
11	Start engine and by opening the throttle, produce a vacuum of 0.92 to 0.98 bar	If this vacuum is not reached or it drops immediately, the seal between the BAS brake booster (A7/7) and master brake cylinder may be damaged or the check valve (17) in the vacuum line (8) may be defective. If the specified vacuum is not reached: ↓ Check, check valve (17).
11			AR43.10-P-0023LW
12	Replace seal between BAS brake booster (A7/7) and master brake cylinder	If a vacuum of 0.92 to 0.98 bar is not reached or drops immediately and the check valve (17) is not defective.
12			AR42.10-P-0300LW
13	Apply the specified force to the brake pedal and read off the line pressure on the pressure tester (051)	In order to cover measurement errors (incorrect force on the brake pedal, incorrect vacuum) and scatter of the measuring devices, a tolerance of 10 bar on the specified value is permissible. The measured value must be within the value range.
13		Brake line pressure	*BE43.10-P-1004-01G
14	Disconnect vacuum tester (030) with test connection (031) from BAS brake booster (A7/7)		AR43.10-P-0024-01V
15	Disconnect pressure tester (051) with connection fitting from brake caliper
16	Remove pedal force meter (060) from brake pedal
17	Install in the reverse order
18	Bleed brake system		AR42.10-P-0010LW
18	Bleed brake system	Only bleed the brake caliper to which the pressure tester (051) was connected.
19	Check brake system for leaks		AR42.10-P-0100-01V

CHECK VALUES FOR PNEUMATIC BRAKE BOOSTER

Number	Designation			Model 205
BE43.10-P-1001-01G	Brake booster	Ø	mm	227
BE43.10-P-1001-01G	Brake booster	Ø	Inch	8/8

CHECK VALUES FOR PNEUMATIC BRAKE BOOSTER

Number	Designation	Model 205
BE43.10-P-1002-01G	Boost factor	≈7

CHECK VALUES FOR PNEUMATIC BRAKE BOOSTER

Number	Designation					Model 205
BE43.10-P-1004-01G	Brake line pressure	Vacuum 0.92...0.98 bar	Force on brake pedal	50 N	bar	22
				100 N	bar	41
				150 N	bar	62
				200 N	bar	80
				250 N	bar	83

FRONT AXLE BRAKE CALIPER

Number	Designation		Model 205 (except 205.086/087/286/28 7/386/387/486/487)
BA42.10-P-1003-10W	Bleed screw on brake caliper	Nm	18

FROND END WITH FRONT REINFORCEMENT

Number	Designation		Model 205
BA62.30-P-1003-02K	Screw/bolt, lower strut to suspension strut tower mounting bracket	Nm	50

FROND END WITH FRONT REINFORCEMENT

Number	Designation		Model 205
BA62.30-P-1004-02K	Screw/bolt, lower strut to firewall	Nm	23

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

Courtesy of MERCEDES-BENZ USA

Fig 4: Identifying Test Connection (168 589 08 63 00)

Courtesy of MERCEDES-BENZ USA