Tools and Materials You'll Need:
* Repair Manual: Essential for detailed instructions and torque specs.
* Jack and Jack Stands: For safe vehicle lifting.
* Wheel Chocks: To secure the vehicle.
* Socket Set (Metric): Various sizes, including deep sockets.
* Wrench Set (Metric): Including open-end and possibly combination wrenches.
* Ratchet and Extensions: For reaching difficult bolts.
* Pliers: Various types, including needle-nose and slip-joint.
* Screwdrivers: Phillips and flathead.
* New Water Pump: Make sure you get the correct one for your specific engine.
* New Thermostat (recommended): While not mandatory, replacing it at the same time is a good preventative measure.
* New Water Pump Gasket: Usually comes with the new pump, but check.
* New Thermostat Gasket (if replacing thermostat):
* Coolant: The correct type for your Blazer (check your owner's manual).
* Drain Pan: To collect coolant.
* Funnel: For refilling the coolant.
* Gloves: To protect your hands.
* Safety Glasses: To protect your eyes.
* Torque Wrench: Crucial for tightening bolts to the correct specification.
Procedure (General Steps – Refer to your repair manual for specifics):
1. Safety First: Disconnect the negative battery terminal. Raise the vehicle securely using a jack and jack stands. Always use wheel chocks.
2. Drain the Coolant: Locate the drain plug on the engine block and the radiator drain plug. Place your drain pan underneath and carefully open the drain plugs to drain the coolant.
3. Remove Accessories: This varies depending on the location of the water pump, but you may need to remove components like the fan, fan shroud, serpentine belt, and possibly the power steering pump or other accessories that obstruct access to the water pump. Take pictures as you go to aid in reassembly.
4. Remove the Water Pump: This typically involves removing several bolts holding the pump to the engine block. They can be difficult to reach and may be corroded. Penetrating oil may be helpful. Be prepared for some coolant leakage.
5. Clean the Mounting Surface: Carefully clean the mating surfaces of both the engine block and the new water pump, ensuring they are free of any debris or old gasket material.
6. Install the New Water Pump: Apply a thin, even bead of gasket sealant (if recommended by the manufacturer) to the new gasket. Carefully install the new water pump, ensuring it seats properly.
7. Reinstall Accessories: Reinstall all removed components in the reverse order of removal. Pay close attention to belt routing and tension.
8. Refill the Coolant System: Carefully add the correct type and amount of coolant to the radiator and reservoir.
9. Bleed the Air from the System: This is critical to prevent overheating. Run the engine for a short time, then check the coolant level and add more as needed. Consult your repair manual for the proper bleeding procedure for your Blazer.
10. Check for Leaks: Carefully inspect all connections for leaks.
11. Lower the Vehicle: Lower the vehicle safely using the jack.
12. Final Check: Run the engine for a while and monitor the temperature gauge and check for leaks.
Important Considerations:
* Rust and Corrosion: Bolts and components in this area are prone to rust and corrosion. Penetrating oil can help loosen them. Be prepared to potentially replace some bolts if they break.
* Torque Specifications: Using a torque wrench is crucial to avoid damaging the engine block or water pump. Incorrect torque can lead to leaks.
* Coolant Type: Use the correct type of coolant specified in your owner's manual.
This is a general guide. Consult a repair manual specific to your 1995 Chevy Blazer 4.3L for detailed, illustrated instructions and torque specifications. If you are not comfortable performing this repair yourself, take it to a qualified mechanic. Improper repair can lead to engine damage.
