Checking oil pressure of power steering pump

AR46.30-P-0100RD

Checking oil pressure of power steering pump

18.06.2015

Model

172 with engine 274

Model

172 with engine 276, 651

as of model year 2016

Shown on engine 651

01

Tester

01a

Throttle valve

02

Test hose

03

Test hose

04

Mounting plate

1

Rack-and-pinion steering

2

Pressure line

3

Return flow pipe



Remove

 Danger !

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

 Danger !

Risk of death caused by vehicle slipping or toppling off of the lifting platform.

Align vehicle between vehicle lift columns and position the four support plates at the vehicle lift support points specified by the vehicle manufacturer.

AS00.00-Z-0010-01A

 Danger !

Risk of injury to skin or eyes from hydraulic fluid spraying out under pressure.Risk of poisoning from swallowing hydraulic fluid.

Depressurize hydraulic system completely before starting any work on it. Wear protective clothing and safety glasses.

AS00.00-Z-0013-01A

1

Remove front upper engine cover.

Model 172 with engine 276, 651
as of model year 2016

2

Clean area surrounding connecting points of hydraulic system

3

Extract oil from power steering expansion reservoir

 Hand pump

*210589007100

4.1

Remove engine compartment paneling

Model 172 with engine 274
Model 172 with engine 276
as of model year 2016

AR61.20-P-1105W

4.2

Detach bottom part of soundproofing

Model 172 with engine 651
as of model year 2016

AR94.30-P-5300W

5

Detach holder for pressure and return line (2, 3) from rack-and-pinion steering (1)

6

Detach pressure line and return line (2, 3) from rack-and-pinion steering (1)

 Collect the discharged oil using a rag.

 Bolt, oil line retaining plate to rack-and-pinion steering

*BA46.20-P-1001-01F

7

Mount test hose (02) with mounting plate (04) onto rack-and-pinion steering (1)

 Use the mounting plate (04) from the supplementary set 230 589 01 90 00.

 Supplementary set

*230589019000

8

Mount return line (3) onto rack-and-pinion steering (1)

 Bolt, oil line retaining plate to rack-and-pinion steering

*BA46.20-P-1001-01F

9

Mount pressure line (2) onto test hose (03)

 Use the test hose (03) from the test adapter 212 589 00 90 00.

 Test adapter

*212589009000

10

Connect testing unit (01) to test hoses (02, 03)

 Tester

*124589062100

11

Fill and bleed the power steering

AR46.30-P-0010RD

12

Start engine and allow it to run at engine speed of approx. 1000 rpm



Check

13

Close throttle valve (01a) and check maximum operating pressure


Run check for brief period only.
Otherwise the oil temperature will increase to an impermissible level.

Pressure in power steering pump

*BE46.30-P-1001-01G

14

Turn off engine

15

Extract oil from power steering expansion reservoir

16

Detach testing unit (01)

17

Detach pressure line (2) from test hose (03)

18

Detach return line (3) from rack-and-pinion steering (1)

19

Detach test hose (02) with mounting plate (04) from rack-and-pinion steering (1)



Install

20

Mount pressure and return line (2, 3) onto rack-and-pinion steering

 Bolt, oil line retaining plate to rack-and-pinion steering

*BA46.20-P-1001-01F

21

Fill and bleed the power steering

AR46.30-P-0010RD



Check

22

Test-run engine and check steering system for leaks and proper operation

Power steering pump test specifications

Number

Designation

Model 172

BE46.30-P-1001-01G

Pressure in power steering pump

bar

120...128

 Steering gear

Number

Designation

Model 172

BA46.20-P-1001-01F

Bolt, oil line retaining plate to rack-and-pinion steering

Nm

18