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Autopapyrus · DAF XF 12.9 MX-13 355 (2017)
https://autopapyrus.com/guides/daf/xf/fuel-injector-replacement/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

DAF XF 12.9 MX-13 355 (2017): Fuel Injector Replacement

Replacing the injectors on a PACCAR MX-13 engine (12.9 L, inline six) requires removing the valve cover, the engine brake (retarder) and the rocker arms to reach the injector hold-downs. The procedure is difficult because the Common Rail fuel lines must be removed correctly and the hold-down bolts must be tightened precisely during installation. A specialty injector puller makes the job much easier and prevents damage to the injector seats in the cylinder head.

Difficulty: Hard Time: 4-6 hours (for a set of 6 injectors) Steps: 21 Tools: Socket set and ratchet, torque wrench (up to 50 N·m (37 lb-ft)), PACCAR MX-13 specialty injector puller (recommended), pry bar or slide hammer for the puller, fuel drain pan, shop rags, cleaning agent for the injector seats.

Part

  • 🔩 PACCAR fuel injector 1861200 / 1861200PR (for EPA10 2013-2020) or 1972591 / BEBJ1D00003 (alternate MX-13 numbers). Delphi equivalents EX631145, BEBJ1D02001, BEBJ1D04001 (for Euro 6) are also applicable. New injector seals (copper washers) are mandatory when replacing

Step by step

21 steps
  1. Disconnect the battery terminals (negative and positive). Relieve the fuel system pressure: open the pressure relief valve on the fuel rail, or disconnect the fuel pressure regulator connector for a few seconds after the engine has stopped.
  2. Remove the valve cover: unscrew the mounting bolts around the perimeter (typically 10-12 M8 bolts) and carefully pry the cover off with a pry bar without damaging the gasket/sealant. Wipe oil and dirt off the exposed cylinder head.
  3. Remove the engine brake (retarder) assembly: unscrew the mounting bolts (usually 4-6 per cylinder) and disconnect the actuator's electrical connector. Remove the assembly without losing the adjustment shims.
  4. Remove the rocker arms or valve bridges over the injector you are replacing: loosen the rocker arm adjusting screws, unscrew the center bolts holding the rocker shafts, and carefully lift the rocker arms up. Lay the parts out in the order of removal.
  5. Disconnect the high-pressure fuel lines from the injectors. Use two open-end wrenches (one as a backup wrench, one on the flare nut) so the injector fitting does not turn. Plug the open fittings with clean rags or caps so dirt cannot get into the system.
  6. Disconnect the electrical connectors from each injector: press the locking tab and pull the connector upward.
  7. Remove the injector hold-down bolt (usually one M8 bolt per injector, located on top between the rocker arms). Remove the hold-down clamp.
  8. Pull the injector out of its seat in the cylinder head. If it does not come out by hand, use the specialty PACCAR MX-13 puller: set the cylinder's piston to TDC (turn the crankshaft to the mark), screw the puller's grip onto the threaded part of the injector (or hook it under the shoulder), brace the puller's lever on the edge of the cylinder head, and extract the injector evenly upward with light taps of a hammer on the puller's impact section or by turning the extractor screw. Do NOT use brute force, as you risk damaging the bore or breaking the injector.
  9. Inspect the injector seat in the cylinder head. Check the copper sealing ring at the bottom of the bore (injector cup/sleeve). If your engine has removable copper sleeves, remove the old sleeve with a special puller (thread the threaded grip into the sleeve, tighten it, and pull it out with a slide hammer). If the sleeves are non-removable (stainless, factory press-fit after 2014), just clean the surface of carbon deposits with a soft brass brush and degreaser. Do NOT scratch the seat with steel tools.
  10. Install a new copper sealing ring (or a new copper sleeve, if applicable) at the bottom of the injector bore. Make sure the ring sits flat, without tilting. Lubricate the seal with a thin layer of clean engine oil.
  11. Install the new injector in its seat: lower the injector vertically into the bore, turning it slightly so the nozzle enters straight. The injector must seat fully against the sealing ring (the injector body usually protrudes 1-3 mm above the cylinder head surface).
  12. Install the hold-down clamp and tighten the hold-down bolt with a torque wrench to 38-47 N·m (28-35 lb-ft). Do NOT exceed this torque, as you risk deforming the injector body and causing failure.
  13. Connect the electrical connector to the injector until the lock clicks.
  14. Connect the high-pressure fuel line to the injector fitting. Tighten the flare nut to 25-30 N·m (18-22 lb-ft). Confirm the exact value in the service manual, since it depends on the fitting type.
  15. Repeat steps 7-14 for the remaining injectors (if replacing a full set).
  16. Reinstall the rocker arms and valve bridges. Tighten the rocker shaft bolts and adjust the valve lash to specification (cold engine: intake 0.38 mm, exhaust 0.76 mm. These are typical MX-13 values; check the exact figures in the service documentation).
  17. Install the engine brake assembly: tighten the mounting bolts in a crisscross pattern to 15-20 N·m (11-15 lb-ft) and connect the electrical connector.
  18. Install the valve cover with a new gasket, or apply sealant (if the design is gasketless). Tighten the cover bolts evenly from the center outward to 10-12 N·m (89-106 lb-in).
  19. Connect the battery terminals and turn the ignition on (without starting the engine) for 10-15 seconds so the pump primes the system and builds pressure. Repeat 2-3 times.
  20. Start the engine. It may run roughly for the first few seconds until the air clears from the fuel lines. Check the fuel line connections for leaks. After 5-10 minutes of running, inspect the area around the injectors. There should be no fuel or oil seepage.
  21. Run a scan tool diagnostic and make sure there are no injector fault codes (P0201-P0206, P0261-P0266, etc.). If needed, perform the injector adaptation/learning procedure (injector coding). For Delphi injectors with Smart Injector technology, the calibration code is printed on the injector body (7 alphanumeric characters) and must be entered into the ECU with dealer software such as DAVIE or an equivalent.

Common mistakes and warnings

  • Working on a high-pressure Common Rail system (up to 2000 bar) is dangerous. You MUST relieve the pressure before disconnecting the fuel lines, or a jet of fuel could injure you. The slightest dirt in the injector seat will cause combustion gas blow-by, overheating and injector destruction, so use only clean tools and lint-free rags. If you have no experience with diesel Common Rail systems and no specialty MX-13 injector puller, go to a DAF or PACCAR service center. Doing the job yourself without the skills can damage the cylinder head, which is a costly repair. After replacing the injectors, calibration (coding) of the new injectors in the engine ECU is MANDATORY. Without it you may get black smoke, increased fuel consumption and power-related fault codes.