25 Steps to Install C7 & C9 HEUI Pumps

Technical Service Bulletin, TSB53018-C

To replace your Caterpillar (CAT) C7 or C9 Engine’s HEUI pump (fuel pump), please follow the below steps:

  1. Remove the two, 10 millimeter bolts with 16 millimeter heads that hold the HEUI pump to the engine.
  2. Remove the oil supply line from the pump.
  3. Remove the fuel filter housing.
  4. If the coolant line runs over the air compressor, you have to remove the line as well.
  5. Remove the electrical connector.
  6. Remove the high pressure supply line to the head.
  7. Remove the two fuel supply lines that run off the back of the transfer pump.
    • Note: You will need a special tappet wrench for this for this fitting, part number 192-5092.
  8. Disconnect the oil supply line from the seal plate; keep the fitting loose so that it is easier to pull the pump.
    • Note: Be careful with the oil supply line, because it bolts behind the air compressor and can crack when removing the pump. If the line cracks, you will need to replace it as well.
  9. Inspect the engine oil pressure line to make sure it is not compromised.
  10. Place the old HEUI pump in a vice and remove all of the old fittings so they can be reused.
  11. Drain the oil and remove the head.
  12. Inspect the pump- especially the solenoid- for any contamination, rust, or metal debris. If any contamination is present, both the fuel and oil systems will need to be flushed and the injectors replaced.
    • Warning: Failing to drain the systems and replace the injectors will fail the new pump!
  13. Prep the new HEUI pump with all of the fittings, resealing them.
    • Note: Be sure to keep the quick-connect fitting loose to help make the reinstall easier.
  14. Install the new HEUI pump into the engine and connect the quick-connect line.
    • Note: Getting the pump in can be difficult unless you don’t have an air compressor.
  15. Replace the oil supply line into the fitting.
  16. Mesh the HEUI pump gears with the engine gears.
    • Note: These are not timed gears, so you will not have to worry about timing alignment.
  17. Torque the bolts to 40-foot-pounds.
  18. Reinstall the filter housing and all lines.

For the C7 Engine’s 20R6642 Pump Kit:

  1. Follow the above instructions.
  2. If equipped, remove the air compressor.
  3. Install the kit’s elbow fitting (part 439-1889) on the 10R8899 pump.
  4. Install the filter (part 503-7470) on the elbow assembly (part 129-2327). The filter is directional and the arrow should point towards the pump.
  5. Align the filter (part 503-7470) with the hose (part 503-7469) and tighten the hose’s fitting onto the filter ‘s mating fitting .
  6. Attach the kit’s hose (part 503-7469) to the engine block’s port.
  7. Reinstall the air compressor if equipped.

Parts included in the C7 Engine’s 20R6642 Pump Kit:

  • 10R8899 – HEUI Fuel Pump
  • 238-5081 – O-Ring
  • 503-7469 – Hose
  • 503-7470 – Filter
  • 129-2327 – Fitting

Lisa Bowman

Dealer Sales, M&D Distributors

Lisa Bowman has over 14 years of experience in Diesel Aftermarket parts, inventory management, and customer service. She spent 9+ years in Seattle, WA, employed by Power Distributing in shipping, receiving, customer service, account management, and procurement. Now, Lisa is currently employed by and based out of M&D Distributors’ Headquarters in Houston, Texas. She is in charge of Service Dealer (SD) Sales, Customer Resource Management (CRM) administration, and assisting the marketing department.

In her spare time, Lisa enjoys riding her Harley, hunting, painting, and spending time with friends and family. She’s raised a daughter, Shelby, who currently attends the United States Merchant Marine Academy. When Shelby is in town for visits, it’s all about shopping, movies and good food!

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