Contents Wiring diagrams Section: Manual & Power Steering All sections

Power Steering System: Overview Chevrolet Silverado 2500 HD

Test Description

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

  1. 5: This step tests the system for restrictions.
  2. 7: This step tests the following components for the following conditions: The pump for internal leaks The power steering pipes for kinks
  3. 8: This step tests the ability of the pump to regulate flow at maximum pressure.
  4. 10: This step tests the ability of the pump to regulate flow under normal operating conditions.
  5. 12: This step tests the internal components of the pump and the gear.
StepActionValue(s)YesNo
DEFINITION: The Power Steering System Test Procedure will perform the following functions: Test the operation of the hydraulic power steering system. Test the operation of the power steering pump and power steering gear. Identify restrictions in the system.
1Inspect the power steering fluid for the following indications of contamination: Milky fluid - water Brown fluid - burnt Debris in fluid - plastic or dirt Is the fluid free of contamination?Go to Step 3Go to Step 2
2Flush the power steering system. Refer to Power Steering System Flushing . Did you complete the procedure?Go to Step 3
3IMPORTANT: In order to accurately diagnose the system, the malfunction must be present during the test procedure. Attempt to duplicate the condition.Is the condition present?Go to Step 4System OK
4Turn the ignition switch to the OFF position. Place a drain pan under the vehicle in order to catch any power steering fluid. Disconnect the power steering pressure pipe/hose from the power steering pump or the power steering gear as necessary. Install the J 44721 Power Steering System Analyzer. See Special Tools . Fill the power steering system. Refer to Checking and Adding Power Steering Fluid (With Hydroboost) or Checking and Adding Power Steering Fluid (Without Hydroboost) . Did you complete the installation?Go to Step 5
5Fully open the J 44721 valve. See Special Tools . Start the engine. NOTE: Refer to Steering Wheel in the Full Turn Position Notice . Turn the steering wheel and BRIEFLY hold the steering wheel against the steering stop in order to release any trapped air from the system. Inspect and ensure that all of the power steering pipe/hose connections are not leaking. Make sure the steering wheel is OFF the steering stop, observe the pressure reading. Is the pressure reading greater than the specified value?1525 kPa (221 psi)Go to Step 6Go to Step 7
6IMPORTANT: A restriction may be present in the power steering system. Turn OFF the engine IMMEDIATELY. Locate and repair the restriction.Did you complete the repair?Go to Step 18
7Allow the engine to run until the engine reaches full operating temperature. Record the pressure reading and flow reading. Partially close the J 44721 valve until the system pressure reaches the specified value, then record the FLOW reading. See Special Tools . 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 13Go to Step 8
8NOTE: Do not leave the valve fully closed for more than 5 seconds, or the pump could be damaged internally. Fully close then open the J 44721 valve 3 times. See Special Tools . Record all of the high pressure readings. Refer to Power Steering Pump Specifications for power steering system pressure relief specifications.Are the 3 high pressure readings within specifications?Go to Step 9Go to Step 15
9Are the three high pressure readings within 245 kPa (50 psi) of each other?Go to Step 10Go to Step 14
10Increase the engine speed to approximately 1,500 RPM. Record the flow reading. Refer to Power Steering Pump Specifications for power steering system pressure specifications. Is the actual flow reading within specifications?Go to Step 11Go to Step 13
11Is the difference between the actual flow reading and the maximum flow specification more than 3.8 L (1 gal) per minute?Go to Step 16Go to Step 12
12NOTE: Refer to Steering Wheel in the Full Turn Position Notice . Turn the steering wheel from steering stop to steering stop and record the FLOW readings at each stop.Is the flow LOWER than 3.8 L (1 gal) per minute?Go to Step 18Go to Step 17
13Replace the power steering pump. Refer to Power Steering Pump Replacement (4.8L, 5.3L, 6.0L, and 6.2L) or Power Steering Pump Replacement (6.6L) or Power Steering Pump Replacement (4.3L) . Did you complete the replacement?Go to Step 18
14Remove the power steering pump flow control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle . Inspect the flow control valve. If any burrs or scratches are noticed on the flow control valve, replace the flow control valve. Do NOT attempt to clean the flow control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle . Inspect the flow control valve bore. If any burrs or scratches are present in the control valve bore, replace the power steering pump. Refer to Power Steering Pump Replacement (4.8L, 5.3L, 6.0L, and 6.2L) or Power Steering Pump Replacement (6.6L) or Power Steering Pump Replacement (4.3L) . Did you complete the repair?Go to Step 18
15Replace the power steering pump flow control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle . Did you complete the replacement?Go to Step 18
16Remove the power steering pump flow control valve and inspect for any wear or damage. Do NOT disassemble the flow control valve. If the flow control valve is worn damaged, replace the flow control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle . Did you complete the repair?Go to Step 18
17The power steering gear is leaking across the piston or bypassing the valve circuit. Replace the power steering gear. Refer to Steering Gear Replacement (Rack and Pinion) or Steering Gear Replacement (Non Rack and Pinion) . Did you complete the replacement?Go to Step 18
18Test the power steering system for the original condition. Does the original condition still exist?Go to Step 5Go to Step 19
19Disconnect and remove the J 44721 from the vehicle. See Special Tools . Connect the vehicle power steering pipes/hoses. Bleed the power steering system and add fluid as necessary. Refer to Power Steering System Bleeding . Did you complete the repair?System OK
IMPORTANT
In order to accurately diagnose the system, the malfunction must be present during the test procedure.
NOTE
Refer to Steering Wheel in the Full Turn Position Notice .
IMPORTANT
A restriction may be present in the power steering system. Turn OFF the engine IMMEDIATELY.
NOTE
Do not leave the valve fully closed for more than 5 seconds, or the pump could be damaged internally.
NOTE
Refer to Steering Wheel in the Full Turn Position Notice .

Power Steering System Test