26SI Series Alternator – Fuel Injection Nozzles

Remove & Install Fuel Injection Nozzles

Start By:

a. remove valve covers

Fluid Spillage Containment

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to “Tools And Shop Products Guide”, NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.

1. Thoroughly clean the area around each of the fuel line connections. Disconnect fuel line connector (1). Disconnect fuel injection fitting (2) from the adapter.

2. Remove bolt (4), the clamp and spacer that hold the fuel injection nozzle in place.

3. Slide the adapter from the cylinder head assembly, and remove fuel injection nozzles (3). If the fuel injection nozzle can not be removed by hand, install Tooling (C), and remove the nozzle.


Before the fuel injection nozzles are installed, check for fuel leakage, the pressure at which the injection nozzle opens, and the amount of fuel (spray pattern) that comes out of the nozzle with Tool (A). See the topic “Testing Fuel Injection Nozzles” in the Systems Operation Testing & Adjusting Manual.

4. Remove carbon seal dam (6) and compression seal (5). If necessary, use Tool (E) to clean the nozzle.

5. Install a new compression seal (5). Install a new carbon seal dam (6) with Tool (B).

6. Clean the bore in the cylinder head assembly with Tool (D). Use an open end wrench or a tap drive to turn Tool (D).

7. Install new O-ring seals on adapter (7) and fuel injection nozzle (3).

8. Install the fuel injection nozzle in the cylinder head assembly. Never put lubricant on the nozzle or bore in the cylinder head assembly.

9. Install the adapter in the cylinder head assembly. Connect the nozzle and fuel injection line to the adapter. Tighten the nuts to a torque of 41 ± 7 N·m (30 ± 5 lb ft).

10. Install the spacer and clamp that hold the nozzles in the cylinder head assembly.

End By:

a. install valve covers