3116 and 3126 Truck Engines Fuel Transfer Pump Replacement

To replace cat 3126 fuel pump you need to follow this procedures:

Removal Procedure

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Remove tube assembly (3) and tube assembly (2) from fuel transfer pump (1). Plug and cap all openings. This helps to prevent fluid loss, and this helps to keep contaminants from entering the system.

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Remove bolts (5) and fuel transfer pump (1) from unit injector hydraulic pump (4) .

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Remove O-ring seal (6) from the unit injector hydraulic pump. Inspect O-ring seal (6) for wear or damage. If the O-ring seal is worn or damaged, use a new part for replacement.

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Remove the fittings for the fuel inlet port and the fuel outlet port from fuel transfer pump (1) .

Installation Procedure

Clean all components and the mating surfaces. Inspect all components. If any component is worn or damaged, use a new part for replacement.

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Install the fittings for the fuel inlet port and the fuel outlet port on fuel transfer pump (1) .

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Install O-ring seal (6) on the unit injector hydraulic pump.

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Position fuel transfer pump (1) on unit injector hydraulic pump (4) .

Install bolts (5). Tighten bolts (5) for fuel transfer pump (1) to a torque of 25 ± 3 N·m (18 ± 2 lb ft).

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Install tube assembly (3) and tube assembly (2). Tighten the connectors for the fuel inlet port and the fuel outlet port to a torque of 18 ± 2 N·m (13 ± 2 lb ft).

Here’s a video on How To Replace a HEUI Pump. Cat C7, 3126, and C9. This video describes everything needed to change a Cat HEUI pump and what special tooling and techniques are needed to change it. Inspection of the pump is also discussed for possible debris in the Injectors.