New Fuel Priming Instructions are Available for Certain 3126B Engines {1258, 1290} Caterpillar

Combine

LEXION 460 (S/N: 6541-UP)

Engine

3126B (S/N: BKD1-UP; DCD1-UP; 1AJ1-UP; 5GL1-UP; 8YL1-UP; DCS1-UP; 7AS1-UP; BDZ1-UP; 8SZ1-UP)

Excavator

322C (S/N: DAA1-UP; FED1-UP; M2H1-UP; HEK1-UP; BYL1-UP; C3R1-UP; EMR1-UP; LAR1-UP; MAR1-UP)

325C (S/N: CRB1-UP; JLC1-UP; S2C1-UP; BTD1-UP; JLD1-UP; BFE1-UP; DTF1-UP; AMH1-UP; CSJ1-UP; M2K1-UP; G1L1-UP; BMM1-UP; S3M1-UP; Y4P1-UP)

Integrated Toolcarrier

IT38G Series II (S/N: JAN1-UP)

IT62G Series II (S/N: AYA1-UP)

Marine Engine

3126B MARINE (S/N: 9ZF1-UP; 3GS1-UP)

C7 MARINE (S/N: C7B1-UP; M7G1-UP; C7X1-UP)

Mobile Hydraulic Power Unit

325C MHPU (S/N: MSG1-UP)

Motor Grader

120H (S/N: 1241-UP; CAF1-UP)

135H (S/N: CBC1-UP; AMX1-UP)

Petroleum Engine

3126B PETROLEUM (S/N: Z2A1-UP)

Pipelayer

561N (S/N: TAD1-UP; CPH1-UP)

Pumper

SPP101 (S/N: 7151-UP)

Track-Type Loader

953C (S/N: BBX1-UP)

963C (S/N: BBD1-UP)

Track-Type Tractor

D5N (S/N: AKD1-UP; AGG1-UP; CFH1-UP; CKT1-UP)

D6N (S/N: CBF1-UP; CBJ1-UP; CCK1-UP; CBL1-UP; ALR1-UP; ALY1-UP)

Truck Engines

3126E (S/N: G3E1-UP; LEF1-UP; CKM1-UP; CRP1-UP; HEP1-UP; 9SZ1-UP)

Wheel Harvester

570B (S/N: CKG1-UP)

580B (S/N: CLT1-UP)

Wheel Loader

938G Series II (S/N: RTB1-UP; PHN1-UP; B9Y1-UP)

950G Series II (S/N: BAA1-UP; AYB1-UP; AYD1-UP; AYL1-UP; AXR1-UP; AYS1-UP; AXX1-UP)

962G Series II (S/N: BAB1-UP; BAC1-UP; BAD1-UP; AYE1-UP; AYG1-UP; AXS1-UP; AXY1-UP)

Wheeled Excavator

M325C (S/N: XJA1-UP; PAN1-UP)

Introduction

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

The new fuel priming instructions helps to prevent failures of the injector plunger spring and injector tip from air being trapped in the fuel system after component replacement.

Inadequate priming can result in air being present in the low-pressure fuel system and inside the injectors. Attempting to start the engine without adequate priming results in an overload condition on injector plunger spring and tips, causing early hour failures.

Illustration 1	g06264933

Installation Procedure

Illustration 2	g06215607
Damaged plunger spring

Illustration 3	g06215611
Cracked injector tip

The proper procedure for priming the fuel system can be found below:

1. Locate the fuel priming pump.

2. Operate the priming pump plunger to fill the final fuel filter. The fuel filter will be filled once there is resistance felt.

   Note: The priming pump may need to be pumped 25 times or more to fill the fuel filter. The fuel priming process may take up to 75 pumps to fill the fuel supply passage.

3. Push and tighten the plunger in a counterclockwise direction by hand.

4. After the fuel system is pressurized, crank the engine promptly.