Water pump oil leak

Tiny
MILMAR_22
  • MEMBER
  • 1999 MITSUBISHI TRUCK
  • 6 CYL
  • 2WD
  • MANUAL
  • 100,000 MILES
We are maintaining a Fuso fight 6d17. The water pump failed by oil mixing with water and vice versa. We replaced it with a new one but after a few drive tests the oil leaks at the water pump shaft. We thought it was a factory defect so we returned it to the supplier to be changed by a new one but it happened again. Are we doing something wrong?
Thursday, February 1st, 2018 AT 5:24 AM

7 Replies

Tiny
KEN L
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You must be leaving out one of the o-rings that seals the the two sections. Did you match up the new unit to the old water pump? Sometimes the changes can be subtle.

Please let us know.

Cheers, Ken
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Friday, February 2nd, 2018 AT 12:29 PM
Tiny
MILMAR_22
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The new water pump is exactly the same as the old one. I am just wondering why the pressure is too high to worn out the oil seal of the water pump shaft and next thing you know, the radiator and fan are covered with oil. Would cutting out the oil supply be an option? Please help. Two brand new water pumps has been broken. Thanks Ken.
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Friday, February 2nd, 2018 AT 5:48 PM
Tiny
KEN L
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I do not see the oil problem? Can you take pictures of the effected area?
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Saturday, February 3rd, 2018 AT 10:17 AM
Tiny
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Hi Ken. This is where the oil comes out. We tried replacing it with a better oil seal but still.
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Sunday, February 4th, 2018 AT 5:08 PM
Tiny
KEN L
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When you say oil do you mean coolant? I do not see where engine oil is near the water pump like you say. Is the replacement pump OEM?
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Monday, February 5th, 2018 AT 10:45 AM
Tiny
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It is engine oil. An oil type water pump. Engine oil is its lubricant instead of grease. The engine oil circulates to the water pump through camshaft.
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Monday, February 5th, 2018 AT 1:44 PM
Tiny
KEN L
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I see now, thanks. The only thing that can make the water pump go out is the pressure relief spring in the oil pump is stuck causing the oil pressure to be way to high knocking out the seal. Does the truck have a oil pressure gauge? Also was the pump a factory pump? Cheap pumps will fail not matter what happens.
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Tuesday, February 6th, 2018 AT 10:49 AM

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