Mazda 3 Service Manual: Water Pump Removal/Installation [Mzr 2.0, Mzr 2.5]
Never remove the cooling system cap or loosen the radiator drain plug while the engine is running, or when the engine and radiator are hot. Scalding engine coolant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system.
Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise 2.5 turns. Step back while the pressure escapes.
When you are sure all the pressure is gone, turn the cap using the cloth, and remove it.
Coolant may have accumulated depending on how many years the water pump has been in use. However, this does not indicate a malfunction if the accumulated coolant does not cover the vapor escape hole.
1. Remove the battery cover..
2. Disconnect the negative battery cable..
3. Remove the plug hole plate..
4. Remove the aerodynamic under cover No.2 and splash shield as a single unit..
5. Drain the engine coolant..
6. Loosen the water pump pulley bolts before removing the drive belt.
7. Remove the generator drive belt with the A/C drive belt still installed and set it out of the way. (MZR 2.0).
8. Remove the drive belt. (MZR 2.5).
9. Remove the drive belt auto tensioner. (MZR 2.0).
10. Remove the idler pulley. (MZR 2.5).
11. Remove in the order indicated in the table.
12. Install in the reverse order of removal.
13. Refill the engine coolant..
14. Inspect for engine coolant leakage..
Water pump pulley
(See O-ring Installation Note.)
O-ring Installation Note
1. Apply engine coolant to a new O-ring.
2. Install the O-ring.