Safety First:
* Disconnect the negative battery terminal before beginning any work.
* Wear safety glasses to protect your eyes from fluid splashes.
* Work in a well-ventilated area because power steering fluid can be harmful if inhaled.
* Have appropriate fluid catch pans ready to contain any spilled fluid.
Removal Procedure:
1. Drain the power steering fluid: Locate the power steering fluid reservoir and carefully drain the fluid into a suitable container. There's usually a drain plug or you can siphon it out.
2. Disconnect the power steering pressure hose: This hose connects to the pump's outlet. Use a wrench of the appropriate size to loosen the clamp securing the hose. Have a rag ready to soak up any residual fluid. Be aware that pressurized fluid will escape. Once loosened, carefully pull the hose off the fitting.
3. Disconnect the power steering return hose: This hose connects to the pump's inlet. Repeat the process as in step 2, using a wrench to loosen the clamp and carefully removing the hose. Again, be ready for a fluid spill.
4. Disconnect the electrical connector: If applicable, there may be an electrical connector attached to the pump. Carefully unplug it.
5. Remove the pump mounting bolts: The power steering pump is typically held in place by several bolts. Use the correct size socket or wrench to remove them. You may need a breaker bar for stubborn bolts. Pay close attention to the location and orientation of the bolts before removal.
6. Remove the power steering pump: Once all the bolts are removed, the pump should be free. It may be slightly stubborn due to corrosion or gasket sealant. Gently rock and pull the pump free. Take note of the pump's orientation and any spacer or shims.
7. Clean the mounting surface: Carefully clean the mounting surface on the engine block to remove any old gasket material.
Reinstallation:
Reinstallation is the reverse of the removal procedure. Make sure to use a new gasket and tighten the bolts to the manufacturer's specified torque. After reinstallation, refill the power steering fluid reservoir to the proper level and bleed the system if necessary (consult your repair manual for bleeding procedures).
Important Considerations:
* Type of pump: There are different types of power steering pumps. While the removal process is generally similar, there might be slight variations depending on the specific pump installed in your vehicle.
* Accessibility: Access to the power steering pump can be limited, especially in a 4x4 truck. You may need to remove other components to gain better access.
* Special tools: You might need special tools like a power steering pump pulley puller depending on the design.
Remember, this is a simplified guide. Always refer to a repair manual specific to your 1990 Chevy Cheyenne 4.3L for detailed instructions, torque specifications, and safety precautions. If you are not comfortable performing this repair yourself, it is best to take your vehicle to a qualified mechanic.
