What is the proper tool to remove precom chambers on these engines? Also what is the thread ?

Thanks, Herb

Uses the 1F0479 chamber removal tool. Chamber part # 7B1844. sorry don't know the thread size.
 

Hi Team,depending on the serial number and/or the type of injector hold down there can be either a push/pull pre-comb where the pre-chamber is held in by the injector hold down clamp and the screw in type OM shows above.I have worked on both types on D17000's in our area.The push in type has a copper diamond shape pre-chamber sealing washer/gasket which requires the pre-chamber to driven against the seat/washer so as to effect a full seating surface band on the diamond edges--the injector hold down system cannot exert enough force to achieve a full seating and distortion of the washer edges.The push in type can be a beast to remove too as carbon and/or rust can cause binding between the head and the pre-comb in the area of the non-threaded section of the pre-comb. if there was ever any leakage due to poor sealing washer seating when first fitted.I have seen the lower sections of the pre-comb that needed to be drilled out of the head after they broke in two when trying to pull them out with the Cat tooling. Pressing on the exposed combustion chamber end of the pre-comb usually just swells the end and makes them harder to remove as the end is domed shaped.I guess this is why the screw in pre-chamber evolved--lol.

Cheers,
Eddie B.

The D17000 Service Manual only references the use of threaded pre-comb chambers and using the tooling I posted.

Hi OM,
I just checked my S/Man. and is as you say--however I have experience of working on early ones which were the older clamped down style as I worked on one fitted this way--was just putting it out there that there can be two types of injector fitment design if Herb or anyone else comes across such on their engine they would be fore armed.
I see in a publication Model Identification Of Caterpillar Engines, Technical Bulletin, dated 1-15-57, Form No P717-15190, that the first D17000 Industrial engine was released in 1935, and the first true Electric Set was released in 1947--10-06-1955 so you may well be correct for an engine of this late a vintage.
Regards,
Eddie B.

parts books for 5e9001 to 9500, book effective 9j5144,and book effective 9j8527 all show drive in chambers. Since d17000 were introduced in 1935, they would have had drive in chamber up to mid 40's. I presume d17000 were changed to threaded chambers at similar time that the D13000 were changed to threaded chambers. Some parts books show field installation replacement heads with threaded chambers.
So it appears service manual is in error when it says threaded chambers for all.

The Service Manual I'm referring to covers D17000 engines for Locomotive,Electric Set, Industrial and Marine published in March of 1952 so is correct for that era.