Cummins/Bosch Engine Parts Fuel Pump 5256607/5256608/4988593 For Cummins 4b3.9 Engine

Safety precautions for fuel pump failure detection

1, Old fuel pump
When troubleshooting a vehicle fuel pump that has been used for a long time, this type of fuel pump cannot be dry tested. Because when the fuel pump is removed, there is fuel remaining in the pump casing. During the energization test, once the brush and the commutator are in poor contact, a spark will ignite the fuel in the pump casing and cause an explosion. Very serious.
2, New fuel pump
No dry test shall be carried out on the newly replaced fuel pump. Because the fuel pump motor is sealed in the pump casing, the heat generated by the power on during the dry test cannot be dissipated. Once the armature is overheated, the motor will be burned. Therefore, the fuel pump must be immersed in fuel for the test.
3, Other aspects
After the fuel pump leaves the fuel tank, the fuel pump should be wiped clean in time, and sparks should be avoided near it, and the safety principle of "wire first, then power on" should be followed.