Tools You'll Likely Need:
* Socket set (metric) with extensions and ratchets
* Wrenches (metric)
* Pliers (needle-nose and slip-joint)
* Screwdrivers (Phillips and flathead)
* Torque wrench
* Drain pan
* Jack and jack stands (crucial for safety!)
* Wheel chocks
* Antifreeze coolant
* New water pump and gasket
* New thermostat (recommended)
* Possibly a clutch fan removal tool (depending on your approach)
Procedure:
1. Preparation:
* Safety First: Disconnect the negative battery cable. Work in a well-ventilated area. Wear safety glasses and gloves.
* Coolant Drain: Locate the drain plug on the radiator (usually at the bottom). Place your drain pan underneath and carefully open the plug to drain the coolant. This may take some time.
* Raise the Vehicle: Securely jack up the front of the vehicle and place it on jack stands. Always use wheel chocks on the rear wheels.
2. Accessing the Water Pump:
* Fan Removal: This is the trickiest part. There are two main ways to remove the clutch fan:
* Using a Clutch Fan Removal Tool: This specialized tool is designed to compress the clutch assembly, allowing you to remove the fan without damaging it. This is the preferred method as it keeps the clutch intact for reuse.
* Pulling the Fan (Less Recommended): You can try to carefully pull the fan off the shaft. However, this risks damaging the fan blades or the clutch assembly. Use caution and consider this a last resort. If you go this route, support the fan's weight during the removal. You might need to use a large puller.
* Belt Removal: Remove the serpentine belt. Consult your repair manual for the proper procedure for your engine – typically this involves loosening the tensioner pulley.
* Accessory Removal (Possibly): Depending on the accessibility of your water pump, you may need to remove some accessories (like the alternator or power steering pump) to gain better access. This will require additional bolts and potentially disconnecting wires.
3. Water Pump Removal:
* Locate the Water Pump Bolts: Once the fan and belt are out of the way, you'll see the water pump. Identify and loosen the bolts securing it to the engine block.
* Remove the Water Pump: Carefully remove the bolts and gently remove the water pump. Be prepared for some residual coolant to spill.
* Inspect the Gasket Surface: Clean the gasket surface on both the engine block and the water pump housing. Any debris could prevent a proper seal.
4. Water Pump Installation:
* Install the New Gasket: Apply a thin layer of sealant (if recommended by the gasket manufacturer) to the new gasket and carefully position it on the engine block.
* Install the New Water Pump: Align the new water pump and carefully install it onto the engine block.
* Tighten the Bolts: Tighten the water pump bolts to the manufacturer's specified torque. Do not overtighten!
5. Reassembly:
* Reinstall Accessories (If Removed): Reconnect any accessories you disconnected earlier, ensuring all wires are correctly connected.
* Reinstall the Serpentine Belt: Reinstall the serpentine belt, ensuring proper routing over all pulleys.
* Reinstall the Fan: If you used a clutch fan removal tool, reinstallation should be straightforward. If you pulled the fan directly, double-check everything is properly aligned before reinstalling.
* Refill Coolant: Carefully add the correct type and amount of coolant to the radiator. Refer to your owner's manual.
* Bleed the Cooling System: Start the engine and let it run until the thermostat opens (you should see coolant flowing). Top off the coolant as needed. Some systems require special bleeding procedures. Consult your repair manual for your specific vehicle.
6. Final Checks:
* Check for Leaks: Inspect for any leaks around the water pump and connections.
* Check Coolant Level: Check the coolant level and add more if needed.
* Test Drive: Take the vehicle for a test drive to ensure the cooling system is functioning correctly. Monitor the temperature gauge.
Important Considerations:
* Repair Manual: A factory service manual or a reputable repair manual specific to your 1997 GMC Jimmy Vortec V6 is essential. This will provide detailed diagrams, torque specifications, and procedures.
* Clutch Fan Replacement: If the clutch fan is damaged or worn, it’s best to replace it. A failing clutch fan can cause overheating.
* Thermostat Replacement: While not strictly necessary, it's highly recommended to replace the thermostat while you're working on the cooling system. It's relatively inexpensive and a preventative measure.
This is a complex repair. If you're not comfortable performing this work yourself, it's best to take your vehicle to a qualified mechanic. Incorrect procedures can lead to engine damage.
