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DIY Water Pump
2002 BMW 745i
Job Time 6 hours
Difficulty Medium

Symptoms: Coolant Leak from front or back of pump or pump has gone bad.

Tools Needed

Torx set
1 ¼ wrench for removing fan clutch

Note: 2002 is a belt driven fan. If you have electric fan procedure may be slightly different and may not need to be removed if you have space.

Step 1. Remove the Fan Clutch. (Fan)
a. Put your 1 ¼ wrench. It is threaded opposite so Right Loosey.
b. Tap and try to loosing. If your lucky it will move then you can just spin the fan off.
c. If it is stuck you need to stabilize the pulley using BMW Tool 11 50 40 or make yourself a homemade one, or remove the belt and use a rubber strap wrench to brace the pulley.
d. Note put anti seize on the threads when you replace

*As you lean over your hood watch the coolant line that goes from the expansion tank across the top of your radiator to a connection on the radiator. The middle piece is plastic and brittle.

Step 2 Remove the Fan Cowl
a. Single Screw in Center by radiator
b. Unplug 2 sensors on left side
c. Slide Cowl Upward from its slots. Try not to bend to much its become brittle and will break easy. Replacements are $50

Step 3. Remove AC Belt (passenger side)
a. Take tension off the belt using a Torx socket and turning left.
b. BMW note. If the drive belt is to be reused: Mark direction of travel and reinstall drive belt in same direction of travel.

Step 4 Remove alternator Belt (drivers side)
a. Take a picture of your belt setup
b. Use a Torx Socket to take tension off belt by turning to left and remove the belt.
c.BMW note. If the drive belt is to be reused: Mark direction of travel and reinstall drive belt in same direction of travel.

Step 4. Remove Vibration Damper
a. Remove 8 screws and it comes out with a plate.
b. It is aligned with a small pin. This must be fitted when you replace
c. 22nm torque
Step 5 Remove the water pump

a. Unlock and detach plug connections
b. Release screw and remove vacuum line holder.
c. Unlock and detach all coolant hoses on water pump.
d. Release screws and remove belt pulley
e. Release screws and remove water pump

Step 6 Installation of new water pump or seal replacement
a. If water pump is good replace seals there are 2 of them
b. Inspect or Replace both coolant pipes that attached to water pump in the rear and coat sealing surfaces with anti-friction rubber coating. I believe this is just BMW speak for liquid gaskets like permatex.
c. Remove coolant thermostat and coolant sensor of faulty water pump.
d. Check coolant thermostat and coolant sensor for damage and replace if necessary.
e. Install coolant thermostat and coolant sensor in new water pump.
f. No liquid gasket is required between the water pump seals and engine block but a small about cant' hurt either.
g. Reassemble engine in reverse order

Cost of Job Water Pump aftermarket $140
Coolant $10
Total Cost $150

Price does not include purchase of Tools, or and breaking of other parts while your in there!

Break something? Here's your reference for replacements

*Disclaimer this is a DIY from my experience do it at your own risk! ***61514;


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