Author Topic: ISL Lift Pump leak  (Read 4613 times)

Paul Schwalen

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ISL Lift Pump leak
« on: May 11, 2010, 06:49:17 PM »
The dreaded leak from the lift pump became noticeable last week.  We have a Cummins ISL 370HP and I read all the posts regarding lift pumps and decided to try and fix it myself.

I called Cummins and they emailed me two files that show the pump and its location.  Also, the view of the pump itself clearly shows which bolts mount the pump to the bracket which is mounted to the forward curb side of the engine high up on the engine block and the torque rating for these bolts.

On our Contessa when you open the raised floor hatch in the bedroom the pump is right there.  The interesting thing is that when I tightened the 3 bolts to the required 110 inch pounds of torque they all took about 1/2 of a turn.  That translates to about 1/32" in vertical movement.  I can't believe that they worked their way loose so my theory is that the gasket shrunk due to the ULSD.  (Cummins told me that they did have some leakage problems when the ULSD first came out but the refineries have since added something to the fuel that solved the problem. This sounds too good to be true.)

Anyway, if you have a lift pump leak and a torque wrench and easy access to the pump the whole job takes less than 1 hour, .  I carry a small 1/4" torque wrench that I got at Harbor Freight for about $20.  It is not the best but works just fine for my limited use. :)