Will a fuel pump off of a D8 2-U interchange with a diesel 75 or RD-8 or a power unit of the same vintage???

I believe it will, the RD-8 became the 1H series which my parts book shows using a 6B3657 fuel pump group with a 1F1793 field changeover replacement and the 2U1-9661 using the 1F1793 unit throughout these serial numbers.

NO, 75 and RD8 had the big pump and 2U had small pump . Lines are differant also

Hi MR22,
I show a major pump change at sr. # 1H3256. Prior to that is a different style pump with relief valve in the pump cover and different line arrangement. Is that what you are referring to as the large pump?? or is there a version before that?
This pump is a 4B3786 and would be replaced by a 1F1793 pump and a 1F1559 plug.

Hi team,
I think MR.22 is refering to the early Flange Mounted Fuel Injection Pump as the BIG Pump. The style fitted to Diesel 35,40,50, etc. and early RD6,RD7, etc. see scan from OMI.
Cheers,
Eddie B.

Hi edb,
Thanks for the info.........the terminology is a little loose:D
Do you have any info on earlier fuel (transfer) pumps???
Earlier than what I listed.

Hi OM,
for the early fuel injection transfer pump I believe the earliest data I have is from Form No 5060B issued June 1941, Servicemen's Reference Book for Caterpillar Diesel Engines.
I'm not aware of anything earlier than this book, the list of available serviceman's ref. books from a 1949 list such as the :- D8-- 1H, 8R, 2U, form 7620C--- D7--7M, 3T, form 7196D, etc. down through D6 & D4--no D2 listed as yet.
The SRB--5060B is listed here also, along with the Fuel Injection Pump Housings book form No--7272C. To the best of my knowledge this is it.
I have an OMI for the D9900 Diesel Engine!!!!!, this is in the General Instruction Book for Early Products, it is a later produced 2 volume loose leaf set of books consisting of reprints of OMI's and a few Servicemen's sections for selected available gas machines--other than the D9900 engine one.
These cost me megga $$$$$ to get in from Cat even with the Dealer employee discount.
Hope this helps,
Cheers,
Eddie B.