Replace water pump on 1997 gmc jimmy 4.3 litre

Thread on type. Loosen fan clutch counter clockwise for removal. Requires 36mm wrench (or adjustable crescent wrench).

a strap wrench should do the trick. there not that expensive.

drain coolant, remove drivebelt, remove upper fan shroud, remove cooling fan and clutch assemblyremove water pump drive pulley mounting bolts, remove upper hose from the water pump, remove water pump mounting bolts, remove water pump from the engine, remove gasket, and make sure that all mating surface are clean and free of gasket materials or burrs

You will have to take the fan and fan clutch off to get to the water pump. It is best to go to oriellys and put a deposit on the fan removal tool it will be easier on you. Than there is only four bolt holding the water on.

It is a bit easier to remove the fan clutch nuts with the belt on but if you have it off already it still is the same procedure. Once you remove the upper shroud half (I think there are 5 small bolts) you will have more room to work with. Start draining the coolant out of the pitcock in the bottom of the radiator and remove the radiator cap. There are 4 nuts holding the fan clutch on to the 4 pulley studs. Take along flat head screwdriver and place it so you are able to pry against 2 of the nuts so you can lock the pulley in place while you loosen the nuts with a closed end (boxed end) wrench. Use the screwdriver to spin the pulley when you are ready to loosen another nut. Be careful to keep your hand on the fan when it is ready to be removed or it may damage the radiator. Do the same thing in reverse when you are ready to install it.

Pretty easy. Just drain antifreeze. Then loosen 4 bolts that holds fan to pulley. Remove plastic fan schroud and fan pulley. Loosen water pump bolts in criss cross pattern and remove water pump. Clean surface install new gasket and water pump install in reverse order. Tighten in staggerd order to keep from breaking and warping. Don't forget to change thermostat good time to replace. Part should be about 50 bucs at your local parts store.

I'll assume you have a 4.0l

The 4.0L engine is equipped with a reverse rotation (counterclockwise) water pump. The word REVERSE is stamped or imprinted on the cover of the viscous fan drive and on the inner side of t he fan. The letter R is stamped onto the water pump impeller. When replacing water pump, ensure proper pump is installed. Installation of the wrong water pump will cause engine overheating.

NOTE:On models with 4.0 L engine, front grill must be removed to access radiator draincock. Draining cooling system can be accomplished by removing drain plug from side of block as well as by loosening radiator draincock. Drain plug is located on lower left side of engine block.

Disconnect negative battery cable. Drain cooling system. Disconnect electric cooling fan connector. Remove electric cooling fan and electric fan shroud assembly (if equipped).
Loosen, but do not remove, 4 water pump pulley-to-water pump hub bolts and 4 viscous fan-to-idler pulley nuts. Remove accessory drive belt. Remove 4 viscous fan to idler pulley nuts, and remove fan and shroud together.
Remove 4 water pump pulley bolts and remove pulley. Remove power steering pump and bracket. Disconnect heater hoses and lower radiator hose at water pump. Remove 4 water pump retaining bolts. Remove water pump.

to install just reverse procedures

Disconnect the negative battery cable, then drain the engine cooling system. 2. Relieve the belt tension, then remove the drive belt. 3. Remove the upper fan shroud, then remove the fan or fan and clutch assembly, as applicable. 4. Remove the water pump pulley. 5. If applicable, loosen the clamp(s) and disconnect the coolant hose(s) from the water pump. 6. Unfasten the retainers, then remove the water pump from the engine. Note the positions of all retainers as some engines will utilize different length fasteners in different locations and/or bolts and studs in different locations. To install: 7. Using a putty knife, carefully clean the gasket mounting surfaces. 8. Apply 1052080 or an equivalent sealant to the threads of the water pump retainers. Install the water pump to the engine using a new gasket, then thread the retainers in order to hold it in position. 9. Tighten the water pump retainers to specification: For the 4.3L engine, tighten the bolts and studs to 30 ft. lbs. (41 Nm). 10. If removed, connect the coolant hose(s) and secure using the retaining clamp(s). 11. Install the water pump pulley, then install the fan or fan and clutch assembly. 12. Position the serpentine belt over the pulleys, then carefully allow the tensioner back into contact with the belt. 13. Install the upper fan shroud, then connect the negative battery cable. 14. Properly refill the engine cooling system, then run the engine and check for leaks.

You can get large pliers, or a pry bar between the bolt heads of the fan.

The text below is from the GM Service manual 4.3L V6 Engine
Water Pump Replacement (4.3L)
Removal Procedure
Drain the cooling system. Refer to Draining and Filling Cooling System .
Loosen the water pump pulley bolts.
Remove the cooling fan and clutch assembly.

Tools Required
J 46406 Fan Clutch Wrench

Removal Procedure
Remove the upper fan shroud.
Remove the fan clutch from the water pump in a counterclockwise direction using the J 46406 .
Remove the fan clutch assembly.
Remove the drive belt. Refer to Drive Belt Replacement Remove the water pump pulley mounting bolts.
Remove the water pump pulley.
Remove the radiator outlet hose clamp from the water pump.
Remove radiator outlet hose from the water pump.
Remove the water pump mounting bolts.
Remove the water pump from the engine.
Remove the water pump gaskets.
Clean the water pump gasket mating surfaces.
Installation Procedure
Install the water pump gaskets.
Install the water pump to the engine.
Apply a sealer (GM P/N 12346004) to the bolt threads.
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.
Install the water pump mounting bolts.
Tighten
Tighten the mounting bolts to 41 N·m (30 lb ft).
Install the radiator outlet hose to the water pump.
Install the water pump pulley.
Install the water pump pulley bolts.
Tighten
Tighten the water pump pulley bolts to 25 N·m (18 lb ft).
Install the drive belt. Refer to Drive Belt Replacement in Engine Mechanical - 4.3L.
Install the fan clutch assembly.
Fill the radiator cooling system. Refer to Draining and Filling Cooling System .
Inspect the cooling system for leaks.