Farm Equipment - WD 45 Injector Pump

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WD 45 Injector Pump

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Category: Allis Chalmers
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=186464
Printed Date: 09 Sep 2025 at 10:35am
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Topic: WD 45 Injector Pump

Posted By: yesmar74
Subject: WD 45 Injector Pump
Date Posted: 16 Feb 2022 at 6:09am

I've been reading a lot that the injector pump should be pulled to make sure it's not stuck before I attempt to start or turn the motor over or turn the pump over on a WD45Diesel that's sat for quite a while. I've also read that just by turning the motor by hand with the fan blades I could determine a stuck pump or not. My question is if do pull the pump, how to get everything timed correctly before pulling pump if I can't turn the motor? Or just be certain that it gets reinstalled exactly the way it came off?

Replies:

Posted By: injpumpEd
Date Posted: 16 Feb 2022 at 8:07am

Obviously the best thing to do is take it off and have your local qualified pump shop go through it, cleaning it up as well as the injectors. Timing it upon installation would involve turning the engine with injectors still out, and finding #1 compression stroke by turning normal direction of rotation(clockwise viewed from front) while having a cork or plug of some sort in the #1 inj hole. When it blows out it's on the compression stroke. Then you can align the proper marks. Get a service manual. Parts for these pumps are nearly extinct, so do everything you can to avoid damaging it. Today's fuel doesn't age well. These tractors do not like sitting!

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210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers!

Posted By: TomMN
Date Posted: 16 Feb 2022 at 4:24pm

A service manual is a great help. I have pictures on my site of what marks to look for when mounting the pump. I wouldn't worry about where it is when you remove it, both the engine and the pump will need to be turned before it goes back on anyway.

https://allis01.com/fossto/56WD45D/ac-wd45d-injection.html" rel="nofollow - https://allis01.com/fossto/56WD45D/ac-wd45d-injection.html

Posted By: Michael Crowe
Date Posted: 17 Feb 2022 at 5:09pm

Toms website is amazing. If you study his pics on the pump timing, and follow the IT instructions it is very easy to do.

Be careful though when you get ready to install; ive helped two people who had AC mechanics install the pump previously and the motors ran rough and started hard. Turns out both were incorrectly timed to piston #6, the one closest to the fuel tank instead of #1, the one closest to the radiator. The easy way to tell is remove the valve cover and make sure both valves are closed.

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The 14th Annual Exclusive AC Swap Meet will be held in Boonville, MO, March 7-8, 2025. See the club website for details: http://www.moacclub.com/

Posted By: injpumpEd
Date Posted: 17 Feb 2022 at 5:31pm

that is why I say find #1 comp stroke with injectors out still, just have an assistant stick a finger over the injector hole, and while turning it by hand the direction of rotation, the finger will be pushed off, indicating compression stroke. If valve cover is already off, looking at rockers can also confirm. These engine speed pumps can really stump even a seasoned mechanic.

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210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers!