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How do you replace the water pump on a 1992 - 1996 Mazda 929?

Tools Required:

- Basic tools with ratchet and socket set to include extensions

- Flat blade and Phillips head screwdriver

- Adjustable wrench.

- Pliers

- Funnel

- New gasket

1. Drain coolant. Place a catch basin of some sort under the water pump and undo the 17 mm draincock in the lower driver’s side portion of the radiator (you’ll need to pry down the plastic splash guard to get to it). Don’t get coolant on the paint (or skin). Collect approximately two gallons of coolant. If the coolant is new and clean, save it and reuse it.

2. Remove the fan and clutch. The cooling fan may be removed separately from the fan clutch, or they may come out as a unit – either way works fine. Disconnect the coolant overflow hose from the overflow tank and pull it out of the fan clutch. Loosen the three large bolts that hold the fan clutch to the water pump pulley and remove them; then remove the bolts and nuts holding the fan and fan clutch to the water pump. There is not enough clearance to remove the bolts holding the fan to the water pump from under the car. Remove these three nuts and bolts from underneath the car while the front wheels are off. If the fan doesn’t come off easily, a few sharp tugs on the fan blade should loosen the rust/dirt/corrosion. Do not pry on the fan to pry it off.

3. Disengage the power steering and air conditioning belts. There are two bolts holding the tension pulley. Remove the first bolt (12 mm head) and loosen the second bolt (14 mm head). Pull on the spring-loaded tension arm to release the belts from the pulley and set the belts aside. (Note that the power steering tension arm also holds the bracket for the vacuum hose for the transmission). To remove the power steering belt completely, insert a long screwdriver or pry bar between the engine block and the power steering pump and pry outward against the pump (which is held by two bolts). Pull inward on the belt at the same time and the belt will come off.

4. Remove the water pump.

- There are only four bolts that hold the water pump to the engine, but they are a little tricky to get to. Remove the upper one first (12 mm head) – a combination of extensions, U-joints and wobble sockets come in handy here. Remove the lower one next.

- Remove the two bolts on the other side of the water pump. If you have a 17 mm deep socket, you can get one of them from underneath without jacking the car up. The other one can only be reached by removing the right front (passenger’s side) wheel and lower plastic fender liner and reaching up in there while lying down under the car.

5. Clean up the gasket surface to remove all traces of the old gasket. Be careful not to drop anything down into the engine!

6. Install the new gasket into the water pump and lay the pump in its place; carefully slide the bolts into place and tighten securely starting with the lower right side. Don’t over torque these bolts.

7. Reattach accessories (power steering, air conditioning) using the reverse of the instructions above. Don’t forget to reattach the ground strap to the water pump.

8. Refill the cooling system. Mix 50/50 coolant/water and pour directly into the radiator. The lower radiator hose can also be removed so that the system gets filled from bottom to top. Replace the overflow hose and radiator cap.

9. Start the engine and ensure that the system has no leaks. Let the engine idle and top up the coolant as necessary. Run it for a good while or drive around until the engine is completely warm. Look for leaks. Turn the heater on full and feel the heater output – this will indicate whether the water pump is working.