CAT 320 fuel system priming procedure

[Gary Layton]

I have been doing a pretty thorough service on my 320...hydraulic, air and fuel system.

I have all the filters replaced, just got the fuel filter swapped late this afternoon. I have never hand primed a diesel system. I followed the O&M procedure for the first part...loosen filter vent, prime until no bubbles flow out the vent...that went OK. The next step is to loosen the injector pump vent bolt and prime it.

I do not know where that vent is. The following pictures are where I think it must be but I need someone to ID the injector pump vent bolt. Also, there is a small knob by the inj. pump in picture 3. Is that also a priming pump? Does the inj. pump have its own priming pump or do I use the one by the fuel pump (that is a LOT easier to access)?

I included pictures of the procedure I am following from the O/M Manual.

 

[Gary Layton]

more...in picture 5, I am touching the priming pump and the fuel filter vent bolt.

 

[Gary Layton]

from O/M Manual

 

[Gary Layton]

And, lastly, from the parts manual. The real-world CAT does not seem to match exactly the parts diagram. I think part 129 (top left of housing in picture 1 of inj. pump) is the vent bolt but I cannot cipher where that is on my machine.

 

[heymccall]

Prime with vent on filter open until no air. Close vent, and prime until pressure on primer. Seat and tighten primer.
Start engine. If it stalls, reprime with bleeder closed. Then restart.
Unless the engine completely ran out of fuel, I've never had to bleed the injection pump.

 

[Delmer]

That is a primer pump on the injector pump in pics 2 and 3. The bleeder is middle of the pic on pic 2, the right side on pic 3 and the bottom on pic 7. If the easy to reach primer doesn't pump fuel out the bleeder, try the hard to reach one. If you're feeling lucky, start it up and bump the RPM up to 1,200 or so as soon as oil pressure comes up.

 

[Gary Layton]

Thanks, McCall...that is what I was hoping might work. All I did was change out fuel filter and fuel/water separator...lost some fuel from the system in the swapping but not major.

I'll prime again tomorrow and try to start it. I did not try to start today.

Thanks, Delmer, for the ID of vent and injector primer pump. The fuel filter primer pump only took about 8 strokes to stop producing bubbles. Maybe I will be lucky.

Appreciate the quick replies.

 

[Gary Layton]

Thanks for the help, guys. I did the priming procedure again today and got the CAT going. It fired up quickly as normal and quickly died. Cranked it about 8 seconds, no go. Cranked another 5 seconds and she fired up and ran great. I took some video of the process. If it's decent I'll post it later.