Test program - ASR II hydraulics - RA42001400824X(42-0824)

Conditions for test

Before test work, connect brake fluid changing equipment.
The hydraulic system must be depressurized before any work on the hydraulics. To do this, switch off ignition. Open bleed screw "SP" on the ASR hydraulic unit (A7/3) and allow the contents of the accumulator to discharge into the brake fluid receptacle.
After the test work, first carry out the pressure accumulator charging process (plug on ASR control unit and start engine, allow engine to run until accumulator is full), then correct fluid level in the brake fluid reservoir.
Test step 1: The specified large tolerance of the pressure value (1.8 - 11 bar) depends on the production tolerances in the pressurizing pump, ASR hydraulic unit and in the check valve of the pressure accumulator.
Test steps 2 and 3: In the event of a defective return pump/charge pump (A7/3m1), either there is no pressure buildup or too slow a pressure build-up (> 60 seconds).
In the event of a defective pressure accumulator, the pressure build-up either takes place quickly to values below 50 bar and then slowly again up to maximum pressure or rapidly and continuously up to maximum pressure.

Special tools

Fig 1: Identifying Special Tools (129 589 00 21 00 54)

Fig 2: Identifying Special Tools (645 589 00 63 00 42 54)

Fig 3: Identifying Special Tools (645 589 01 63 00 42 54)

Fig 4: Identifying Special Tools (201 589 00 99 00 15 54)

COMMERCIALLY AVAILABLE TOOLS OR TESTERS

Designation	e.g. Company, part number for ordering
Pressure tester	Teves D - 6000 Frankfurt, Order no. 3.9305-0205.4/01
Brake fluid changing equipment	Romess-Rogg Selecta D B Sturmbuhlstr. 182 D - 7730 Villingen-Schwenningen

Connecting testers

Test step 1

With the ignition switched off, disconnect connector to ASR control unit (N39/1).

Fig 5: Identifying Bridges To Socket Box

Bridges to socket box (example test step 1)

Test steps 1, 2 and 3

Pressure tester to ASR hydraulic unit (A7/3) connection "SP"

Fig 6: Identifying ASR Hydraulic Unit

SYMBOL CLARIFICATION

TEST PROGRAM

Test step	Scope of test	Measuring equipment/test connection	Operation/requirement	Nominal value	Possible cause/remedy
1	ASR pressurizing pump (M15)	1 0 bar to "SP" N30/1 1 11 20 27 33 34	Ignition: ON (max. 60 s)	1.8-11 bar	Cable interrupted, hydraulic connections leaking, replace ASR pressurizing pump (M15).
2	Return pump/charge pump (A7/3m1)	2 50 bar to "SP"	Engine: start	Pressure increases rapidly to 50-110 bar, then continues slowly to 150-200 bar. Charging time max. 60 s	Hydraulic connections leaking, replace hydraulic unit (A7/3). Also refer to ASR electrics/ electronics test program (test steps 39 and 40). Also refer to test step 3!
3	Pressure accumulator	2 50 bar to "SP"	Engine: start	Pressure increases rapidly to 50-110 bar, then continues slowly to 150-200 bar. Charging time max. 60 s	Hydraulic connections leaking. Replace pressure accumulator.