How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Cat Man Your Own Question
Cat Man
Cat Man, Caterpillar Engine Expert
Category: Heavy Equipment
Satisfied Customers: 8863
Experience:  23 Years Caterpillar Engine experience.
Type Your Heavy Equipment Question Here...
Cat Man is online now
A new question is answered every 9 seconds

How do you replace the injector seals for a 3176 cat?

This answer was rated:

How do you replace the injector seals for a 3176 cat?

Hi. Thanks for using JA! I will try and help you out.


When changing the Injector seals on a 3176 engine, you will need a special tool. This tool is used to "Ream" the injectors cups.


The 3176 engine has copper injector cups. Any time an injector is removed, the cups need to be reamed to ensure a good seal when the injector is installed.


What king of problem are you having?

Customer: replied 5 years ago.

I am getting diesel in oil and i believe that one or more seals are leaking.

I see. It is either coming from the top injector O ring, or an injector.


I would cap off the return line and use the hand primer pump t pump up the system. If there is a top O ring leaking, you will see it.


If you do not see an O ring leaking, it is lost likely an injector.


In order to find which injector is putting the fuel in the oil, they will need to be pressure tested.

Customer: replied 5 years ago.

Ok but how would I change an injector. Is there only the one special tool involved, and what is the procedure?

Yes there is just one tool involved. I can get you the tool number and procedure. I'll be back in a moment.

the tool needed for the injectors cups is(NNN) NNN-NNNN The tool itself is expensive. It is the complete tool group to replace the cups. You only need the reamer. You should be able to get just the reamer form the dealer.


Here is the procedure. << click here

Cat Man and other Heavy Equipment Specialists are ready to help you