Im not exactly sure about draining and changing the oil on my fuel* pump. I really dont know the right way to do it . Im not exactly sure which bolts do what. Which is the when its full plug, which is the fill plug. Its a Ford Leahman 120. My first time aye? BB
1) Remove the "level plug" on the side of the injector (item 2 from the manual) Make a note if, and how much oil comes out. Bob Smith says when it starts getting excessive, fuel is bypassing the injector pump pistons). No oil coming out of the level plug hole is a good thing!
2) Remove the flat head fill screw at the top of the injector (item 1 in the manual.).
3) Remove the drain plug (item 3 in the manual) and catch the oil in something. I guess about a cup or two come out.
4) Put the drain plug back in.
5) Put new oil in the fill plug until it starts running out the level hole. (same oil wt as engine. I use Shell Rotella 30 wt, same as in the engine).
6) Put all the plugs back in and yer done!
Here is a good tip:
After you drain the oil do the following.
1. Fill the oil to the proper level according to the oil level plug hole. When it JUST starts to show or come out it is full.
2. Get a CLEAR plastic bottle. I use a dishwasher bottle. Now drain the NEW oil into the bottle.
3. Mark the oil level on this bottle. This now becomes an important reference line for future injector pump oil drains.
4. Pour the new oil back into the injector pump.
5. Next time you need to drain the injector pump oil, drain it into this marked plastic container. Compare the used oil level with the mark on the container. The oil should be close to the mark. If not, or if you see that each oil change is showing an increase in the oil level, then you know the injector pump is letting diesel fuel past the injector pump pistons and its getting time for a rebuild. If you ever notice the used oil levels higher than they should be, then change the oil MORE FREQUENTLY, maybe 40 hrs or so. That is a temporary work around until you get the injector pump rebuilt. A new injector pump is >$3000, so dont neglect it !
Second, I highly recommend that you contact American Diesel Corp about your engine if you have any questions.
Here is my fuel injector pump labeled for you -