IAW TM 9-2320-272-24-1 for the M939A2 series trucks page 3-202 paragraph 3-69.
Tools required: General mechanic’s tool kit
Materials required: O-ring
Equipment Condition:
-Hood raised
-Parking Brake set
-Engine coolant drained (paragraph 3-63)
-Fan belt removed (paragraph 3-71)
You have to look up these paragraphs for any special tools and what you have to do in those 'work packages'.
3-63 General mechanic’s tool kit
3-71 Torque wrench (Appendix E, Item 146)
So now you have to look up the item in Appendix E, Item 146 and that comes up as:
Item number 146 is the Torque Wrench, 3/8-In Drive Model TE-12A with the NSN 5120-00-230-6380 and is found in the set with this supply catalog 4910-95-CL-A31 which with further research turns out to be the Shop Equipment, Automotive Maintenance and Repair: Field Maintenance, Basic, Less Power. This Shop Equipment set has the NSN 4910-00-348-7696.
The GMTK listed has the supply catalog: SC5180-90CL-N26. You can look up this supply catalog on line and it will give you a list of what tools are in it. You won't need all the tools but that's the list of what is in the set.
The O-ring required is:
Item 462 with nomenclature O-ring and part number 100478. It is NSN 5330-00-081-9289. Researching the NSN on that top secret website called google, using the search of "o-ring 100478" I get the answer that it is a Cummins 100478 part. I also cross referenced the NSN and the term o-ring just to validate. Several places have it for sale cheap.
Now to dig deeper, go to the parts manual which in this case is TM 9-2320-272-24P-1. The picture is figure 119 shows 5 items and the items are listed in figure/page 119-1.
1 PAOZZ 2930012688751 15434 3802081 PUMP,COOLING SYSTEM .................................. 1
2 PAOZZ 5331012721123 15434 3902089 . O-RING PART OF KIT P/N 3802389 PART.......... 1
OF KIT P/N 3802389
3 XAOZZ 2930012688751 15434 3802081 . PUMP,COOLING SYSTEM ................................. 1
4 PAOZZ 5305012077447 15434 3900677 SCREW,CAP,HEXAGON H................................... 1
5 PAOZZ 5305012453193 15434 3900621 SCREW,CAP,HEXAGON H ................................... 4
Item 1 is the water pump replacement kit with the o-ring (item 2 which is the same o-ring we found before) and water pump (item 3). Item 4 is one bolt and Item 5 is a different bolt that you need 4 of. Using this listing, we go through the columns from left to right:
Column 1 Item number from the figure (picture) on page 119
Column 2 is the 5 digit SMR code (don't worry about this)
Column 3 is the 13 digit NSN which you need for your search
Column 4 is the manufacturer 'CAGE' code. This code gives you the name of the manufacturer by going to the BINCS website:
https://cage.dla.mil/search//begin_search.aspx In this case the 15434 CAGE code comes back as Cummins.
Column 5 is the manufacturer part number.
Item 4 is Cummins (we know it is Cummins by the Cage code) part number 3900677 which comes back as a M8 30 bolt. Use the NSN to validate the part number if you want.
Item 5 you'll have to do a search on. My battery is dying on my computer.
