Hello again...still workin' on that ol' Cat from previous posts and I have yet another question. Is there a special socket that fits the fuel fitting that screws into the combustion chamber to remove it on a 955C, motor #12A 781? It seems to have a knurled edge. I've tried different sockets with no luck. I have the tool (splined bolt) to remove the combustion chamber so I can install new washers and O rings, but I can't get the fitting that the fuel line screws onto out to remove the chamber. I'll learn the ins and outs of this ol' machine yet!

Thanks in advance for your response!
Greg.

Have you tried a 6 point 1" socket? Torque to 100 foot pounds.

I haven't tried a six point socket. The fitting is round with small notches all the way around it. I've tried 12 point 15/16" sockets and they almost work, but just barely slip when torque is applied. I will try the 6 point, 1" tomorrow though, Thanks for your answer.

Greg.

Not sure but this is just a idea,could it be a Torx style head or similar

...not sure if they had torx when these ol' machines were made, but it's an idea. I'm also not sure if they have a torx socket that big. The biggest I've seen is E-20, but again it's worth a try! Thanks for your help!

No worries, Thought it may be a long shot

I can,t remember for sure but it seems Cat had a special socket for it that was splined for it.Been too many years since I worked on one.

Just wondering if someone did a neat job on it with a cold chisel? Doesn't sound like it though. All of them I ever saw were a plain hex nut. This would likely be a D330, D330C or a 3304???

We are talking about the hold-down nut for the injector in the PC chamber, right? If CAT made it, they will sell a tool to remove it. Might not be as much trouble as making something.

If you have the 1" holdown nut out, the fuel fitting as you are calling it comes straight out. It doesn't un-screw. It might be stuck in there, maybe if you try a little penetrating oil and wiggle it a bit it will come out.

Tom

Tom has it right:)
No special tool required......same as D4-7U D-315.
They have been known to be a bit sticky but need to pull straight out.