Fuel Feed Pump and Priming Pump

FUEL FEED PUMP AND PRIMING PUMP

DISASSEMBLY

1. Removing the push rod
- Pull out the push rod.







2. Place the fuel feed pump in a vise, remove the plug, gasket and pull out the piston spring and piston.







3. Disassembling the priming pump
It is recommended that the priming pump not be disassembled unless the rubber seat in the piston part of the pump has become defective or the piston has seized or is rusty.
- Apply a wrench to the Hex section at the bottom of the cylinder and remove the priming pump assembly.
- Remove the check valve spring and check valve.

INSPECTION
Wash all disassembled parts in cleaning solvent. Carefully check for scratches, cracks or damage. Replace faulty parts as necessary.

















Gauze filter
Check the gauze filter clogging.

REASSEMBLY
Before assembling the feed pump, replace old gaskets and O-rings with new ones.
1. Insert the piston, piston spring and gasket, and tighten the plug.
2. Install the discharge side check valve, check valve spring and gasket, and tighten adapter and priming pump.
3. Install the push rod in the housing.

NOTE: Coat the threads of the plug with the adhesive agent.







SUPPLY PUMP TEST

Suction test
1. Attach a hose to the supply pump suction port and insert the other end into a fuel oil container.

NOTE: Ensure suction head of approx. 1 m (3 ft).

2. Operate the injection pump at 100 rpm.
3. Fuel oil must be discharged in less than 40 seconds.







Priming pump test
1. Fully loosen the priming pump's screw cap.
2. Operate the priming pump using the screw cap, at 60 to 100 strokes per minute.
3. Fuel oil must be discharged in less than 25 strokes.







Capacity test
1. Place discharge hose in a measuring cylinder (157970-0500).
2. Operate the injection pump and check the supply rate, referring to the following table:












Feed pressure measurement
1. Connect the hose (157984-8400) between the supply pump discharge port and the pressure gauge.
2. Operate the injection pump at 600 rpm.
3. Ensure that the supply pump maintains a feed pressure of 333 - 412 kPa {3.4 - 4.2 kgf/cm4, 48 - 60 psi}.







Air tightness test
1. Plug the supply pump discharge port using the plug (029111-4050).
2. Apply 196 kPa {2 kgf/cm2, 28 psi} air pressure to the suction port.
3. Immerse the supply pump in a container of fuel oil, and check for air leakage. There must be no air leakage.