AC Combo Fuel & Vacuum pump

Jeff_Lee · Post by **Jeff_Lee** » Thu Aug 13, 2015 10:03 pm

For my '51 M38 I have found an AC 4698 combo vacuum and fuel pump. I am not sure what is correct for this model jeep, and the pump (and many other things!) have been changed out or modified since it's Gov't Issue.

Is this a correct pump for the '51? Is this an acceptable unit to provide fuel, and vacuum for my wipers, if not exactly correct?
Should this model pump be installed with the fuel pump spacer on the L134 engine?

Thanks and regards, Jeff

Post by **wesk** » Thu Aug 13, 2015 10:58 pm

That is not a correct pump. The 4698 is the last four digits of the AC part number. Look in your ORD 9 SNL G-740 (M38) Parts Manual. Pages 72 & 73. There are 4 pump part numbers listed there. 9917, 9585, 2659 or 2147 would be correct pumps. In the M38 ORD 8 two more are listed 2655 & 3209

The Army eventually used the later M38A1 pumps on all M38/M38A1/M170's.

From the M38A1 ORD 9 SNL G-740 pages 82 & 83 those correct pump #'s are 9810, 4069, & 4260.