Hummer H2. Manual — part 2111

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC STARTING POINT - POWER STEERING SYSTEM

Begin the system diagnosis by reviewing the system Description and Operation. Reviewing the Description and
Operation information will help you determine the correct symptom diagnostic procedure when a malfunction
exists. Reviewing the Description and Operation information will also help you determine if the condition
described by the customer is normal operation. Refer to Symptoms - Power Steering System in order to
identify the correct procedure for diagnosing the system and where the procedure is located.

SYMPTOMS - POWER STEERING SYSTEM

Visual/Physical Inspection

z

Inspect for aftermarket devices which could affect the operation of the power steering system.

z

Inspect the easily accessible or visible system components for obvious damage or conditions which could
cause the symptom.

z

Inspect the power steering reservoir for the proper power steering fluid level and condition.

Symptoms List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

z

Power Steering Fluid Leaks

z

Rattle, Clunk, or Shudder Noise from the Power Steering System

z

Whine or Growl Noise from the Power Steering System

z

Steering Effort Hard in One or Both Directions

z

Steering Effort Too Easy in One or Both Directions

POWER STEERING SYSTEM TEST PROCEDURE

IMPORTANT: Review the system description and operation in order to familiarize yourself

with the system functions. Refer to Power Steering System Description and
Operation .

2004 Hummer H2

2004 STEERING Power Steering System - Hummer H2

Fig. 3: Recirculating Ball System
Courtesy of GENERAL MOTORS CORP.

Callouts For Fig. 3

Test Description

The numbers below refer to the step numbers on the diagnostic table.

Callout

Component Name

1

Power Steering Return Hose

2

Power Steering Pressure Hose

2004 Hummer H2

2004 STEERING Power Steering System - Hummer H2

5: This step tests the system for restrictions.

7: This step tests the following components for the following conditions:

z

The pump for internal leaks

z

The power steering pipes for kinks

8: This step tests the ability of the pump to regulate flow at maximum pressure.

10: This step tests the ability of the pump to regulate flow under normal operating conditions.

12: This step tests the internal components of the pump and the gear.

Power Steering System Test Procedure

Step

Action

Value

(s)

Yes

No

DEFINITION: The Power Steering System Test Procedure will perform the following functions:

z

Test the operation of the hydraulic power steering system.

z

Test the operation of the power steering pump and power steering gear.

z

Identify restrictions in the system.

1

Inspect the power steering fluid for the following indications of
contamination:

z

Milky fluid - water

z

Brown fluid - burnt

z

Debris in fluid - plastic or dirt

Is the fluid free of contamination?

-

Go to

Step 3

Go to

Step 2

2

Flush the power steering system. Refer to Flushing the Power Steering
System .
Did you complete the procedure?

-

Go to

Step 3

-

3

Attempt to duplicate the condition.Is the condition present?

IMPORTANT:

In order to accurately diagnose the system, the malfunction must be
present during the test procedure.

-

Go to

Step 4

System

OK

4

1. Turn the ignition switch to the OFF position.

2. Place a drain pan under the vehicle in order to catch any power

steering fluid.

3. Disconnect the power steering pressure pipe/hose from the power

steering pump or the power steering gear as necessary.

4. Install the J 44721 Power Steering System Analyzer. See Special

Tools and Equipment .

5. Fill the power steering system. Refer to Checking and Adding

-

2004 Hummer H2

2004 STEERING Power Steering System - Hummer H2

Power Steering Fluid .

Did you complete the installation?

Go to

Step 5

-

5

1. Fully open the J 44721 valve. See Special Tools and

Equipment .

2. Start the engine.

3. Turn the steering wheel and BRIEFLY hold the steering wheel

against the steering stop in order to release any trapped air from
the system.

4. Inspect and ensure that all of the power steering pipe/hose

connections are not leaking.

5. Observe the pressure reading.

Is the pressure reading greater than the specified value?

NOTE:

Refer to Steering Wheel in the Full Turn Position Notice in
Cautions and Notices.

1379

kPa

(230

psi)

Go to

Step 6

Go to

Step 7

6

Locate and repair the restriction.Did you complete the repair?

IMPORTANT:

A restriction may be present in the power steering system. Turn off
the engine IMMEDIATELY.

-

Go to

Step 18

-

7

1. Allow the engine to run until the engine reaches full operating

temperature.

2. Record the pressure reading and flow reading.

3. Partially close the J 44721 valve until the system pressure reaches

the specified value, then record the FLOW reading. See Special
Tools and Equipment .

4. Subtract second flow reading from the first flow reading.

Is the flow DECREASE greater than 3.8 L (1 gal) per minute?

4827

kPa

(700

psi)

Go to

Step 13

Go to

Step 8

8

Fully close then open the J 44721 valve 3 times. Record all of the high
pressure readings. Refer to Power Steering Pump Specifications for
power steering system pressure relief specifications. See Special Tools
and Equipment .Are the three high pressure readings within
specifications?

NOTE:

Do not leave the valve fully closed for more than 5 seconds, or the
pump could be damaged internally.

-

Go to

Step 9

Go to

Step 15

9

Are the three high pressure readings within 245 kPa (50 psi) of each

-

Go to

Go to

2004 Hummer H2

2004 STEERING Power Steering System - Hummer H2