BobCat 753 – ENGINE COMPONENTS AND TESTING – Checking

The injection pump contains parts which have a very close tolerance and its operation has a direct effect on the performance of the engine.

The tools listed will be needed to do the following procedure:

MEL1237 – Adapter Fuel Line
MEL1173A – Pressure Gauge

To check the discharge pressure at the fuel injection pump, use the following procedure:

Disconnect a high pressure fuel line from the injection pump. Loosen the other end of the same fuel line so it can be turned away from the fitting.

Connect the adapter fuel line (Item 1) [Figure 70-70-14] to the fitting and connect the pressure gauge (Item 2) [Figure 70-70-14].

Turn the flywheel to increase the pressure. If the pressure can not reach the allowable limit, replace the INJECTION PUMP assembly.

Measure the time needed to decrease the pressure from 2133-1990 PSI (14707 -13721 kPa). If the measurement is less than the allowable limit, replace the DELIVERY VALVE.