How an In-Tank Fuel Pump Wears Out

Here is the in-tank fuel pump from an '82 931.  I removed the metal shell that surrounded the motor and impellers.

Here it is taken apart.

The problem I see with this design is that the fuel runs directly through the electric motor.  Since gasoline isn't probably the best lubricant, the brushes wear out the commutator as you can see above.

Here is another shot of the motor and how much corrosion it can accumulate. 

If you want to know more about how electric motors work, click here.

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01/09/2002