Removing Installed Fuel Pump

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
Tinwoodsman
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Removing Installed Fuel Pump

Post by Tinwoodsman » Fri Mar 23, 2018 8:08 am

I need to service my GPW fuel pump and can't get to the bolt on the left side. Any method to get this done. I did not cut a slot in the bolt head when I installed the pump. :oops:


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Re: Removing Installed Fuel Pump

Post by Joe Gopan » Fri Mar 23, 2018 8:15 am

Quarter inch socket set, 1/4" drive ratchet, 6" or 10" extension, 1/2" 6 Point socket. It will come off like magic. :wink: With correct tools one can change the fuel pump in less than 20 minutes.
NOTE: do not install a bolt that will contact the Camshaft. Original bolts were 5/16"-18 X 7/8" with split lockwashers. 3/4" length works OK. :wink:
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Chuck Lutz
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Re: Removing Installed Fuel Pump

Post by Chuck Lutz » Fri Mar 23, 2018 8:35 am

To add to Joel's post....when you bolt it back on, if you can't compress the spring-loaded arm to get a bolt started, just tap the starter (with the ignition OFF) to rotate the pump cam lobe away.
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Re: Removing Installed Fuel Pump

Post by dpcd67 » Fri Mar 23, 2018 8:48 am

When I reinstall them, I cheat and use an Allen head bolt; makes it 1000 times easier to install and remove.
On the M38, it uses a bolt with a two inch tall head on it that is readily accessible. Hard lesson learned and corrected.
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Re: Removing Installed Fuel Pump

Post by Joe Gopan » Fri Mar 23, 2018 8:53 am

Do not install M-38 Bolts, about 5/8" too much thread, the M-38annd M-38A1 use a very thick Spacer (800361). The M-38 bolts will contact the Camshaft.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
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Mark Tombleson
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Re: Removing Installed Fuel Pump

Post by Mark Tombleson » Fri Mar 23, 2018 9:26 am

Image

For your GPW, don't forget to cut a slot in your F marked bolt like my originals... so you have the option of using a screwdriver! :D
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Mark Jesic
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Re: Removing Installed Fuel Pump

Post by Mark Jesic » Fri Mar 23, 2018 10:51 am

I did that on my previous jeep Mark. It worked brilliantly, and saved a lot of spitting and swearing. :D

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dpcd67
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Re: Removing Installed Fuel Pump

Post by dpcd67 » Fri Mar 23, 2018 3:50 pm

Of course do not use an M38 bolt; the point is that they recognized that a standard short hex bolt was a bad idea and corrected it.
Last edited by dpcd67 on Fri Mar 23, 2018 5:09 pm, edited 1 time in total.
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Tinwoodsman
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Re: Removing Installed Fuel Pump

Post by Tinwoodsman » Fri Mar 23, 2018 4:14 pm

Thanks for the replies and I read previous posts that recommended the 1/4" socket and extension. I have a 1/4" drive Craftsman socket set and I have tried every way I can think of but the socket will just not grip the bolt head. Close, but no cigar!!!!

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Re: Removing Installed Fuel Pump

Post by ritterdl1945 » Fri Mar 23, 2018 5:22 pm

I tried the same 1/4 inch Craftsman socket set and had the same problem. The diameter of the socket was to large so I ground the diameter slightly and also shortened the length of the socket (I shortened the 6 point end, the end that goes on the bolt) and that let it clear the obstacles and worked great. I have used it on several engines now without any problems.
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Tinwoodsman
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Re: Removing Installed Fuel Pump

Post by Tinwoodsman » Fri Mar 23, 2018 7:08 pm

I will try that. Thanks!

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Re: Removing Installed Fuel Pump

Post by willik43 » Sat Mar 24, 2018 1:13 am

My trick, for left side screw at least.
BenzinPumpa-Sroub.jpg
BenzinPumpa-Sroub.jpg (48.13 KiB) Viewed 763 times
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Re: Removing Installed Fuel Pump

Post by Joe Gopan » Sat Mar 24, 2018 3:43 am

My 1/4" Drive Set is Snap-On, the socket fits perfect. Try the similar CCKW Fuel Pump if you think the Jeep is tough.-Takes a few hours. :wink:
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

Tinwoodsman
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Re: Removing Installed Fuel Pump

Post by Tinwoodsman » Sat Mar 24, 2018 8:02 pm

I tried the shortened socket and was able to move the fan side bolt but I think my reproduction fuel pump must be slightly larger at the base near the bolts. I will definitely be able to remove it but will use one of the modification options for and replace the fan side bolt upon reinstallation. That to all for the suggestions.

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MrVisB
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Re: Removing Installed Fuel Pump

Post by MrVisB » Sat Mar 24, 2018 9:27 pm

We found that the only difference to the first tool set solution was to use the extension with a wobble head feature. That let us maneuver the bolt into position to start tightening by hand, then get the rear/ right bolt in to pull the pump body into position. Then back and forth till tight.
Oh and also dropped a loose nut into the socket to get the left bolt started while keeping the bolt shaft forward. Otherwise, the bolt keeps sliding deep in the socket and there isn't enough sticking out to get the threads started.
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