Thanks. CC. I’m laughing at myself right now because that Was so Obvious The pre chamber is stepped inside , with bothe steps being threaded. The upper step, where the injector threads in, is a little shorter And larger diameter than the lower step, which I assume was intended for the removal tool.

I will measure thread diameter and thread pitch on the injector and go down one size smaller. That should be the size I need.

Thanks

I’m back.
The injector threads look to be 1.745 OD with a thread or 12 TPI. I was hoping to find a bushing, stud or bolt that size, then build a puller.

I found an old ACMOC thread from 11 years ago where a guy went through the same scenario, but no pics and no dimensions are mentioned.

Where would a person go to find a nut/ bolt or bushing with OD of 1.745 and TPI of 12 ?

I done online searches for over an hour....

Thanks

"TOGNOT" wrote:

I’m back.
The injector threads look to be 1.745 OD with a thread or 12 TPI. I was hoping to find a bushing, stud or bolt that size, then build a puller.

I found an old ACMOC thread from 11 years ago where a guy went through the same scenario, but no pics and no dimensions are mentioned.

Where would a person go to find a nut/ bolt or bushing with OD of 1.745 and TPI of 12 ?

I done online searches for over an hour....

Thanks

i think that's 3/4" NFT, Cat seems to use that thread in a few places

McMaster Carr lists 1-3/4 x 12 threaded rod but it’s relatively expensive about $100 for a 3' piece of grade 8

Hi Team,
sorry I have not been able to post the scan below until now--just found it by downloading all my Attachments since computer crash stripped everything out of old laptop.

Hope this makes sense, it is a tool with two threaded sections from what I can gather that screws into the body bore of the P-C and the differing threads lock and enable the chamber to be screwed in or out as needed.
I stand to be corrected.
Cheers,
Eddie B.

"edb" wrote:

Hi Team,
sorry I have not been able to post the scan below until now--just found it by downloading all my Attachments since computer crash stripped everything out of old laptop.

Hope this makes sense, it is a tool with two threaded sections from what I can gather that screws into the body bore of the P-C and the differing threads lock and enable the chamber to be screwed in or out as needed.
I stand to be corrected.
Cheers,
Eddie B.

Good post Eddie.
I have been watching this thread and thinking it cannot be a push in combustion chamber.

Tognot,

Can you do a leak down test to perhaps narrow down where the problem lies before going through all of these complex and frustrating sequences?

Based on my research. This PC. Chamber is pressed in. I think that because it. Has threads inside it, not a hex Shape. As others. Have pointed out, it seems a threaded Puller Must be screwed in to the pc then pulled out with a tower type puller set up

The only other possibility ( and I have not seen reference to this) is the threads deep inside the pc are left handed and it might unscrew. Does not makes sense there would be no way to install it!

I not think of how to pressurize the prechamber with out pressuring the combustion chamber . I would hear air leaking but not know if it was coming from a leaking prechamber or a head gasket. It not like a gas engine and hearing a leak from intake or exhaust side. If I am not understanding this or anyone has an idea you won’t hurt my feelings by pointing out my oversight!

I think if I can get a 1 3/4 bolt to screw into the pc, then I can weld some grade 8 all thread to the bolt. Thread the bolt/ thread device into the pc. Slide a piece of pipe over the device, with 1-2 Inches out the top. Then with washer and or bearing to facilitate turning , tighten a nut on the top of the all thread. “Should “ pull out the pc .

If the c is good/ intact then it’s most likely my head gasket.

Thanks everyone for you ideas and help

If it won’t come out, then maybe it’s threaded like Eddie is thinking. I would think a parts book page for that serial number would show the PC chamber threads or press fit area next to the copper washer.

I don’t have anything that early I don’t think but I could be wrong about the picture in the parts book. The 3j3501-up book just doesn’t show any detail of that area.

As I remember, you’re sure of which cylinder has the leak, so that’s about as far as a leak down test can take you diagnosing a coolant leak.

I have the parts book, and based on the numbers mine is not and “early” 3j. I posted a pick ( on 7/28/20) of the pre chamber, it does not show threads. But as Rome pointed out , there is a set screw to not forget.

Ill get my hands on a 1 3/4 bolt and keep you posted