6CTA M2 420hp fuel lift pump leaks

[1969Roamer46]

Happy New Year!

When manually priming one of my engines, fuel started leaking out of the rubber bellows covering the manual pump piston. I believe the seal is shot but there don’t appear to be rebuild kits for these pumps. The SBMAR store only shows the newer style pumps (M3). Other Cummins part sellers list a variety of lift pumps with different part numbers: 3936318, 3917998, and 3917999, none of which cross-reference the others, so presumably they’re not interchangeable. One seller lists two pumps with no part numbers, but the description for one says it’s for engines with “rotary” injection pumps, and the other is for “non-rotary” pumps. My injector pump is Nippon Denso, and I don’t know if it’s “rotary” or “non-rotary.”

None of the sellers list specs for the various pumps, and the pictures for all of them look like they’re externally the same part. Does anybody know which pump is the right one for a mid- to late-90s 420hp 6CTA M2?

The forum isn’t giving me an option to post a picture, but you can see my pump at https://1969chriscraftroamer46.files.wordpress.com/2022/07/dsc08971.jpg

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[1969Roamer46]

Thanks Tony! It looks like that number’s been superseded and the current one is 4988747.
Cheers,
Q

[Tony Athens]

QSOL brings of this part number for your serial number—–Not that pictures mean much on QSOL, but it “looks” right. –

Part Number 3932230

[1969Roamer46]

I believe it’s 45342555.

[Tony Athens]

Best to post and engine serial number–No guarantees, but we have to start with that. Not less than 10 “varieties” of that style pump.

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