Power Steering Pump Delivery Pressure, Checking, Vehicles With 12-Cylinder Engine

Special tools and workshop equipment required

Used Oil Collection And Extraction Unit:SMN372500
Torque Wrench 1331 5-50Nm:VAG1331
Power Steering Test Unit:VAG1402
Power Steering Test Unit - Adapter 3:VAG1402/3
Power Steering Test Unit - Adapter Hose:VAG1402/6
Hose Clamps - Up To 25 mm:3094

Test Prerequisites

Ribbed belt/ribbed belt tension OK
Sealing of system
Hoses/lines are not kinked or constricted

Checking

-- Place the vehicle on a hoist. Refer to RAISING AND LOWERING WITH OPEN AND CLOSED AIR SUSPENSION SYSTEM .

-- Remove the noise insulation. Refer to Noise Insulation, Removing and Installing .

-- Remove the left wheel housing liner. Refer to FRONT WHEEL HOUSING LINER, REMOVING AND INSTALLING .

-- Clamp off the intake hose -2- and the return hose -1- with the :3094 .

Fig 1: Identifying Intake Hose And Return Hose

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

The return hose -1- has restrictors, which can be detected by feeling the hose.
The :3094 must not be secured on the return hose -1- in the area around the restrictors. The restrictors will get damaged.

-- Engage the tester -3- on the control arm -1- using a hook -2-.

Fig 2: Identifying Tester

Courtesy of AUDI OF AMERICA, LLC

-- Place the :SMN372500 below to collect the hydraulic fluid.

-- Mount the :VAG1402 as shown in illustration.

Fig 3: Installing V.A.G 1402

Courtesy of AUDI OF AMERICA, LLC

Pressure line with separating point -item 8- OVERVIEW - HYDRAULIC LINES AND RESERVOIR, VEHICLES WITH 8-CYLINDER ENGINE
Power Steering Test Unit - Adapter Hose :VAG1402/6
Power Steering Test Unit :VAG1402
Power Steering Test Unit - Adapter Hose :VAG1402/6
Power Steering Test Unit - Adapter 3 :VAG1402/3

-- Attach the :VAG1402 hoses to the open connections on the pressure hose as illustrated.

Tightening specification: 40 Nm

-- Make sure that the lever on the :VAG1402 is in position -2-.

Fig 4: Ensuring Lever On Pressure Gauge Stands In Open/Closed Position

Courtesy of AUDI OF AMERICA, LLC

-- Lower vehicle.

-- Remove the :3094 .

-- Start engine without giving gas.

-- Turn the steering wheel from lock to lock about 10 times.

-- Switch off engine and, if needed, fill hydraulic fluid in reservoir.

NOTE:

To avoid damage to pump, observe the following:

Pressure gauge shutoff valve must not remained closed longer than 10 seconds during this test.

Start engine without giving gas and run at idle.

Read the pump pressure immediately after starting at idle speed (have it read by second technician, if necessary).

Because pressure falls over the course of the test, the highest pressure shown is the decisive measurement.

-- Now check delivery pressure.

-- Start engine.

-- Raise the vehicle.

-- Close the shutoff valve to position -1- while the engine is idling and read the pressure (the lever must point away from pressure hose). Do not perform measurement longer than 10 seconds.

Fig 5: Ensuring Lever On Pressure Gauge Stands In Open/Closed Position

Courtesy of AUDI OF AMERICA, LLC

Delivery Pressure Specified Value: 120 to 135 bar (1741 to 1958 psi)

If the specified value is not reached, replace the power steering pump. Refer to POWER STEERING PUMP, REMOVING AND INSTALLING .

-- Switch off engine.

-- Remove the :VAG1402

Union nut tightening specification: 40 Nm

-- Bleed the steering. Refer to STEERING, BLEEDING AFTER REPLACING .

-- Check power steering fluid level. Refer to POWER STEERING FLUID LEVEL, CHECKING .

-- Check all open line connections for leaks. Refer to STEERING, CHECKING FOR LEAKS .

-- Lower the vehicle onto its wheels. Refer to RAISING AND LOWERING WITH OPEN AND CLOSED AIR SUSPENSION SYSTEM .

Tightening Specifications

Refer to REAR NOISE INSULATION, REMOVING AND INSTALLING .
Refer to FRONT WHEEL HOUSING LINER, REMOVING AND INSTALLING . .