Tuesday, May 30, 2006

Cat Diesel Engine-Model 3116 installing injectors

Cat Diesel Engine injector installation on a 3116.
Before installing MUI {mechanical unit injector}injectors on a 3116 diesel engine the first thing to check is the brass sleeve in the cylinder head. It has the job of providing a seating surface for the injector, so any visible wear will require you to get the sleeves machined or replaced.









  1. clean out injector sleeve bore.
  2. installing o-rings on the injector tip is no longer required since the seating tool creates a seal between the injector body and seat. With the injector main body o-ring installed apply a light film of engine oil.
  3. seat the injector in the bore of the head and push down firmly on the return spring until a noticeable click is heard.
  4. turn injector until it engages with fuel control rack.
  5. torque hold down bolt to 9 ft lbs + or - 2 ft lbs.

Use injector seating tool to seat injector into it's bore.

  1. the seating tool is supplied by Caterpillar and must be used or compression may leak past injector into the fuel system.
  2. re-torque injector hold down bolt when seating procedure is completed.
  3. picture shows seating tool set up outside of the engine to clearly see how it works. Torque the three seating tool mounting bolts down to 20 ft lbs then seating bolt{top} to 25 ft lbs wait a few seconds then retorque.

The next step is Synchronization which I will post soon. I hope you can use this information when installing an injector on your 3116 Cat Diesel Engine

2 comments :

Anonymous said...

YOUR BLOG IS INTERESTING AND HELPFUL FOR THE WHY YOU SHOW WHAT YOU ARE DOING.
THE SEAL ON THE INJECTOR TIP HAS BEEN REMOVED BECAUSE THEY CHANGED THEY SEAT AREA OF THE INJECTOR. USED TO BE VERY WIDE AND NOW IS QUITE NARROW. THEY ALSO FOUND THAT THE SEAL BROKE DOWN WITH TIME AND MADE THE INJECTOR LOOSEN.
THE INJECTOR SEAT BETTER WITH OUT THE SEAL, HAVE INSTALLED MANY INJECTORS, AND CHANGED THE SLEEVES IN CYL. HEADS FROM WHEN THE SEAL IS USED, BECAUSE OF LEAKAGE BY THE SEAL DAMAGING THE SLEEVE. THEY ALSO SEND LITATURE WITH THE INJECTOR TELLING YOU NOT TO PUT THE SEAL ON THE INJECTOR.
HOPE THIS IS HELPFUL TO YOU.

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