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catmastertech, Technician
Category: Heavy Equipment
Satisfied Customers: 2356
Experience:  19 years Cat, 3 years Case
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Star: tools needed..a water pump on a 3406E cat engine its

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any specific instructions or tools needed to replace a water pump on a 3406E cat engine its in a 1999 Western Star engine s# XXXXX with 1LW

No special tools need for replacing the pump. Kit usually has all the seals needed for replacement. Be sure to replace seals on both sides of the collar in the end of the oil cooler or it will leak. Instructions below.


NOTE: Intermittent leakage of a small amount of coolant from the weephole is not an indication of water pump seal failure. Weepage is normal to ensure proper lubrication of the coolant seal faces. Replace or repair the water pump only if a large amount of oil or coolant leakage or a constant flow of coolant is observed draining from the weephole in the water pump housing.

1. Drain the coolant from the engine into a suitable container for storage or disposal.

2. Remove the alternator and alternator mounting group from the engine.

3. Remove engine oil cooler (1) from the engine. Refer to the Disassembly and Assembly, "Remove and Install Engine Oil Cooler" for additional information.

4. Loosen hose clamp (2).

5. Remove bolts (4) and water pump elbow (3) from water pump (5).

6. Check the condition of the O-ring seal used between elbow (3) and water pump (5). If the part is worn or damaged, replace the part.

7. Remove the bolts from the timing gear cover and water pump (5). Remove water pump (5).

Typical Example

8. Check the condition of O-ring seal (6) on water pump (5). If the part is worn or damaged, replace the part.

9. Install the water pump in the reverse order of removal.

10. Fill the engine with coolant to the correct level. Refer to the Operation and Maintenance Manual, "Refill Capacities" in the Maintenance Section.


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Customer: replied 8 years ago.
Is it possible to work the water neck from the oil cooler without removing the cooler ..I had thought someone told me that once

Yes the neck is were the adapter collar with the seals on both sidesis that I reffered to. It is bolted on the side of the pump with two bolts. The adapter on the back of the pump has four bolts and it will be helpful to remove it from the hose to help clear the pump when removing it.


I want to cation you about the plate in the end of the water pump. It has two screw holes to force it out. It will jam it you don't do it by hand. Work slowly and switch bolts often to lift it out. If it has any pitting or damage replace it. I usually replace it anyway.


Item 2 below.



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Customer: replied 8 years ago.
thanks for the information , going to replace it tonight
Thanks for the "accept", always glad to help.