Joined: Mar 10, 2013 Posts: 105 Location: Stevensville, Montana
Posted: Thu Aug 27, 2020 9:59 am Post subject: M38A1 Fuel Pumps
Since original pumps are hard to find, has anyone found a viable replacement that will work? Searching the web I came across these two.
https://www.quadratec.com/products/917709_03.htm https://www.quadratec.com/products/917709_04.htm
They are different in appearance but one states it will fit the A-1. However, both state they will fit a CJ3A which is basically the civilian version of the M38. The reason I mention this is because I read where the M38 and the A-1 used the same fuel pumps.
Anyone have some insight? _________________ 1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
Joined: Oct 28, 2008 Posts: 99 Location: Fuquay-Varina, North Carolina
Posted: Thu Aug 27, 2020 12:00 pm Post subject:
The thick spacer dictates the fuel pump pressure.
Make sure you have one.
Had a more modern aftermarket dual action fuel pump on the Civilian 64 CJ5 when I got it and the fuel pressure was way too high. Had to run a fuel pressure regulator to keep from always flooding the carb.
Don't know if these will physically fit, but the fuel pressure might be too high also.
Used a rebuild kit on mine for the M38A1, but I've not gotten it running to test it.
There are many fuel pumps from the jeep line that will fit and work on the M38/M38A1 (L-134 & F-134) engines. Some require some adaptation. The most common civilian dual action pump is the CJ3B F-134 unit that matches the engine but needs the vacuum lines adapted from tubing fittings to hose tubes. To regualte the pump's output pressure Willys went with varied thickness pump to block spacers. So when you substitute a civvy pump and it's pressure is incorrect with the original 9/16" thick spacer then just fabricate different thickness spacers to come up with the desired pressure.
There are about 6 different military dual action pumps used on the M38/M38A1/M170 series jeeps. The military simply kept superseding to the later pumps in their supply system. Yes they all will work on all three jeeps.
If you do not use vacuum wipers then you can certainly substitute a civvy single action pump. Just work in the correct thickness spacer to regulate pressure correctly. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Mar 10, 2013 Posts: 105 Location: Stevensville, Montana
Posted: Thu Aug 27, 2020 1:08 pm Post subject:
Ok I'm going to go with one in the link. Anyone else using it and know the thickness of the required spacer? I searched the forum and I think I found my answer 1/8 spacer. Is this right?
https://www.quadratec.com/products/917709_04.htm _________________ 1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
I searched the forum and I think I found my answer 1/8 spacer. Is this right?
Can't say either way without knowing the AC part number of the fuel pump. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Oct 02, 2014 Posts: 1910 Location: South Carolina, Dorchester County
Posted: Mon Aug 31, 2020 6:29 pm Post subject:
Nope. August not April. How do I know? Because I bought it. Needed a re-buildable core for a spare. A little pricey at $87.50 (delivered, with tax), but patience got the best of me. _________________ Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51
“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari
Have you tried calling the suppliers? There’s no way they have everything listed on line. If you’ve ever seen photos of their inventory you can see that. Army Jeep Parts, Midwest Military, Brent Mullins Jeep Parts, Quarter Ton Military, etc.. Plus you have a chance to talk to some really nice and knowledgeable folks in most cases, and possibly develop a relationship. That’s important in any hobby, including this one. Those guys all know each other, and can help.
Joined: Mar 10, 2013 Posts: 105 Location: Stevensville, Montana
Posted: Tue Sep 01, 2020 10:43 am Post subject:
RonD2 wrote:
Nope. August not April. How do I know? Because I bought it. Needed a re-buildable core for a spare. A little pricey at $87.50 (delivered, with tax), but patience got the best of me.
That's strange because when I click on the link it clearly shows it end April 29, 2020.
Updated: Never mind I went further back and opened the original listing and it shows Aug. I went and tried the link again and it now says Aug. Don't know whats going on but I should have taken a photo of it. _________________ 1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
Last edited by cobra5 on Tue Sep 01, 2020 10:52 am; edited 1 time in total
Have you tried calling the suppliers? There’s no way they have everything listed on line. If you’ve ever seen photos of their inventory you can see that. Army Jeep Parts, Midwest Military, Brent Mullins Jeep Parts, Quarter Ton Military, etc.. Plus you have a chance to talk to some really nice and knowledgeable folks in most cases, and possibly develop a relationship. That’s important in any hobby, including this one. Those guys all know each other, and can help.
There is one on eBay, from Bulgaria? You are on your own there.
They are around but don't seem to come up as frequently as one would think. _________________ 1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
That site does not offer a AC part number for which their odd number pump is a sub for. You are back to experimenting with spacers till you find one the gives the correct operating pressure. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum