Currently Cummins PT fuel supply system is widely used in construction machinery, PT pump maintenance is a key technology of diesel engine repair.
Overhaul should pay attention to the following steps.
when we dismantle PT pump, we usually do it from outside to inside, and from complete assembly to parts, and pls pay attention to below issues during dismantle.
1. use Copper rod to knock slowly when part is locked. Prohibit to use hammer.
2. there must copper shell padded before clamping the pump, otherwise it is easy to break pump body.
3. Driveshaft disk can not pry, the first means to scald by hot water, then pry using 2 square-mouth screwdrivers.
4. The internal process of pump is highly precisive, we can use silk cloth to rub during cleaning proces instead of hairbrush and metal brush which will scratch the surface of parts.
examining and repair
To examine all the dismantled parts, and then decide if there parts must be repaired or replaced, following ways will help you to examine.
1. To use vernier caliper to check internal diameter of driveshaft bushing, it should be replaced larger than 19.11mm.
2. If the governor plunger tongue drived off or damaged, it should be replaced by new ones.
3. when membrane in AFC controller was damaged, it should be replaced and O-ring must also be replaced.
4. the overall drive gearshaft must be replaced when they were worn out obviously.
5. oil seal lip on Pump case must avoid injury, otherwise it will cause leakage.
6. it must be replaced for dirve gear with serious bite.
7. Tachometer shaft has common injuries like root fracture and biten gear, it should be replaced wholly when it has problems.
8. To worn-out governor plunger, the plunger model must be consistent when replacing new ones, it is not workable if not.
9. it must be replaced when presure-regulating valve of gear pump is damaged.