Power Steering Pump Flow Control Valve Replacement - Off Vehicle Hobourn 600 Series

Important: 

•	In order to ensure correct reassembly, record or mark all information as specified in the procedure.

•	Cap the hose connections.

1. Disconnect the hose connections
2. Remove the pump. Refer to Power Steering Pump Replacement .
3. Clean the exterior of the pump with solvent.
4. Tip the pump in order to drain the oil from the intake port.
5. Rotate the shaft in order to remove the oil from the internal cavities.

1. Use the pump mounting bracket or flange in order to clamp the pump assembly to a bench vise.
2. Disassemble the following components:

2.1.	The discharge adapter (5)

2.2.	The seal (4)

2.3.	The spring (2) and combination flow control and relief valve (3) from the pump housing (1)

1. Clean all parts with clean solvent. Blow dry all parts.
2. Inspect the discharge adapter for external damage, damage to the threads and the cross hole on the orifice.
3. If any damage is present, use the discharge adapter kit in order to replace the discharge adapter.

Inspect the following components for excessive burning, scoring, wear or oversize condition:

3.1.	The valve bore

3.2.	The by-pass hole

If there is damage, replace the pump assembly.

3.3.	The flow control valve (3) assembly

Faulty internal valve components are difficult to visually determine. Low pressure may be a sign for valve replacement. The valve must move smoothly in the valve bore.

If movement is not free or there is no movement, install a replacement valve kit.

1. Lubricate the valve bore.



2. Lubricate the new seal (4).
3. Assemble the following components:

3.1.	The spring (2) and valve (3) into the valve bore (1).

Check valve for movement.

3.2.	The new seal (4) to the discharge adapter (5).

3.3.	The valve cap (5) to the valve bore.

Tighten the discharge adapter finger tight.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Clamp the pump mounting bracket or flange in a bench vise. Do not distort the sealing surface of the flange mounting.

Tighten
Tighten the discharge adapter to 65 N·m (48 lb ft).

5. Install the pump. Refer to Power Steering Pump Replacement .