- Engine:
- 3126 (S/N: 1WM1-UP; 4ES1-UP; 1BW1-UP; 8HW1-UP; 7LZ1-UP)
- Truck Engines:
- 3126E (S/N: G3E1-UP; LEF1-UP; CKM1-UP; CRP1-UP; 9SZ1-UP)
- 3126B (S/N: BKD1-UP; 1AJ1-UP; 8YL1-UP; 6PZ1-UP; 7JZ1-UP; 8SZ1-UP)
Use care when servicing HEUI pumps in Table 1. When the fuel and oil line fittings are assembled to the pump, an excessive torque can damage the threads of the pump ports. If the pump requires service, refer to Illustrations 1 and 2.
When you service the pump drive gear, inspect the pump drive gear. If the pump drive gear is loose or damaged, the pump should be replaced and the engine oil filter should be changed.
Plug (2) and plug (18) are the only plugs that are serviceable. The other plugs of the pump group are not serviceable. Check the other plugs of the pump group for leaks. Replace the pump if any of the other plugs on the pump group are leaking. Inspect the O-ring seal. If the O-ring seal is worn or if the O-ring seal is damaged, replace the O-ring seal.
| Unit Injector Pump | Base Pump Group | Reman |
| 107-1228 | 109-4327 | 10R-7054 |
| 134-0467 | 135-5459 | 10R-7053 |
134-0467 Unit Injector Hydraulic Pump Gp
 | |
| Illustration 1 | g01254703 |
(1) Tighten the bolt to the following torque. ... 108.8 ± 13.6 N·m (80 ± 10 lb ft)
(2) Tighten the plug to the following torque. ... 6.0 ± 0.7 N·m (53 ± 6 lb in)
(3) Injection actuation pressure control valve (IAPCV)
(4) Tighten the bolt to the following torque. ... 24.5 ± 2.5 N·m (18 ± 2 lb ft)
(5) Tighten the valve to the following torque. ... 50 ± 5 N·m (37 ± 4 lb ft)
Note: Lubricate the seals prior to assembly. The coil and the valve assembly must be assembled as a matched set.
(6) Tighten the inlet of the oil pump to the following torque. ... 26 ± 3 N·m (19 ± 2 lb ft)
(7) Tighten the plug to following torque. ... 10.75 ± 1.25 N·m (95 ± 11 lb in)
(8) Tighten the outlet of the oil pump to the following torque. ... 23 ± 2 N·m (17 ± 1 lb ft)
(9) Tighten the outlet of the fuel pump to the following torque. ... 17.5 ± 2 N·m (13 ± 1.5 lb ft)
(10) Tighten the inlet of the fuel pump to the following torque. ... 17.5 ± 2 N·m (13 ± 1.5 lb ft)
107-1228 Unit Injector Hydraulic Pump Gp
 | |
| Illustration 2 | g01254704 |
(11) Tighten the bolt to the following torque. ... 108.8 ± 13.6 N·m (80 ± 10 lb ft)
(12) Tighten the bolt to the following torque. ... 24.5 ± 2.5 N·m (18 ± 2 lb ft)
(13) Tighten the inlet of the oil pump to the following torque. ... 26 ± 3 N·m (19 ± 2 lb ft)
(14) Tighten the inlet of the fuel pump to the following torque. ... 35 ± 3 N·m (26 ± 2 lb ft)
(15) Tighten the outlet of the fuel pump to the following torque. ... 35 ± 3 N·m (26 ± 2 lb ft)
(16) Tighten the valve to the following torque. ... 50 ± 5 N·m (37 ± 4 lb ft)
(17) Tighten the outlet of the oil pump to the following torque. ... 23 ± 2 N·m (17 ± 1 lb ft)
(18) Tighten the plug to the following torque. ... 6.0 ± 0.7 N·m (53 ± 6 lb in)
Note: Lubricate the seals prior to assembly. The coil and the valve assembly must be assembled as a matched set.