How to replace Aftertreatment Fuel Doser Injector/ 7th injector in Heavy Duty Mack & Volvo trucks - MOTIV8 Engineering
  • Please read this manual carefully before installation.
  • Please also refer to the Mack / Volvo Service Manual in conjunction with this manual.
  • After the installation has been completed, please keep this manual for future reference.
  • If the installation was done in a shop, please make sure to give this manual to the owner.

Kit Contents

Required tools

  • Mack / Volvo workshop service manual
  • Mechanic’s tool kit


  • This product was designed specifically for the application specified. If an attempt is made to use this product on another car other than specified, you will risk damaging this part and components related to it.
  • Please have regular maintenance checks to ensure the item remains securely fitted.
  • Do not use any excessive force when using this product as you risk damaging the product or other parts.
  • This product must be installed with the appropriate tools and equipment to prevent any electrical failures, injuries, or bodily harm.


Preparing for replacement:

  1. Park your vehicle.
  2. Engage the parking brake ensure your vehicle will not move. Shut off the engine and ignition, and remove the key from the ignition switch.


  1. Remove all body elements according to the vehicle manual to get access to the Doser.
  2. Find where the 7th Injector is located.
  3. Gently unscrew the nut (14 mm) fixing the 7th Injector tube.
  4. Disconnect the fuel tube from the 7th Injector.
  5. Gently unscrew the 2 bolts (8 mm) fixing the 7th Injector on the pipe.
  6. Remove the old 7th Injector with the gasket.
  7. Clean the contacting surface.
  8. Install the new 7th Injector and the new gasket in reverse order.
  9. Tighten the 8 mm bolts with torque 10+- 1.5 Hm.
  10. Connect the fuel tube.
  11. Tighten the 14 mm nut with torque 25+- 6 Hm.
  12. Install the removed body elements in reverse order.


If you do not feel confident doing the job yourself, have a certified technician perform the replacement.

You can find new one in our store here: 

Fuel Doser 7th Injector for Mack & Volvo D13 12-17 | 21407621 22009269 – MOTIV8 Engineering (