Fuel Pump Rebuild

madmike · Post by **madmike** » Mon Jun 11, 2012 7:27 pm

This is an informational post for those who might journey into the interior of your M38A1 fuel pump AKA, AC 4535. This is a dual action pump with fuel and vacuum sides. On the vacuum side, there are two different diaphrams possible. One early and one late. You might have guessed by now that I bought the wrong one.

The rebuild kits are identified as either a T or W (for window type) so you will need to disassemble yours first to determine which you have. I purchased my kit based on model year not knowing at the time that my A1 engine had been swapped out by the military for an earlier engine. But any year pump could be on yours.

The good news for me is that the supplier is sending the correct W type gratis without my having to buy a complete rebuild kit to get the one part I need.

Also, I have the underwater fording type venting and the hand lever to manually pump the fuel to the carb. The download does not show this lever so pay attention during disassembly to orient the part correctly on your way back up. Otherwise, the download was very helpful as no instructions came with the kit.

Hope this helps you. I saw no mention of this change in kits anywhere but the suppliers apparently know about it. I understand the remaining W type is just a real pleasure to hook up, being a blind area to fish around in. I may have an update to this post telling you to never attempt this without first locking up your guns and hammers in a remote area.

Mike

Post by **wesk** » Mon Jun 11, 2012 9:55 pm

All the reputable kit dealers know to ask for the pump part number on it's flange before selling you a kit. I try to stay with Then & Now for pump kits.

pacho · Post by **pacho** » Tue Jun 12, 2012 6:39 am

Hi thanks for the information, I have to buy a kit, Could you recomended me a dealer?

Tks

whydahdvr · Post by **whydahdvr** » Tue Jun 12, 2012 7:17 am

Then & Now in MA as Wes mentioned or Peter DeBella or Army Jeep Parts or Midwest Military. Any of them will have a high quality repair kit.

RICKG · Post by **RICKG** » Tue Jun 12, 2012 7:23 am

2X on Then and Now.. I had them do the pump rebuild
and was 2 weeks turnaround including ship time..

pacho · Post by **pacho** » Tue Jun 12, 2012 8:48 am

Thanks guys

Regards

Post by **wesk** » Tue Jun 12, 2012 8:49 am

The thing to keep in mind is the Army manual for fuel pump rebuilding and repair is meant to be used in conjunction with the jeep's parts manual IE ORD9 SNL G-740 or ORD9 SNL G-758 and their related ORD 8's. If you refer to these manuals they list the different diaphragms and which pumps they go in and they list the Army repair kits and which pumps they are used on.

Then & Now is the most informed manufacturer of kits and provides outstanding overhauls in house. They are not the only show in town but they share the most data with you on line.

http://www.maritimedragracing.com/antiq ... cellar.htm

The vacuum pump diaphragm referred to above is explained there as well:

The full size from the Then & Now site can be viewed at:
http://www.maritimedragracing.com/4b4fb6d60.jpg

madmike · Post by **madmike** » Wed Jun 13, 2012 4:01 pm

One additional source is where I got my kit. Surplus City Jeep Parts in Oroville, Ca. (530) 533-2500, or (530) 534-9956.

Mike