WD45 Diesel
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=172802
Printed Date: 22 Aug 2025 at 2:45pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: WD45 Diesel
Posted By: Brad-MN
Subject: WD45 Diesel
Date Posted: 14 Jul 2020 at 1:46pm
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My 45 diesel keeps blowing out the secondary fuel filter and causing a leak. I'm positive that the fuel pump is overpressurizing the system and causing this. I took the pump off the side of the injector pump and I see no way to adjust the fuel pressure. Am I missing something or is that just the way it is? It's a Bosch PSB pump.
------------- 1930 U 1938 A 1941 WF |
Replies:
Posted By: Boss Man
Date Posted: 14 Jul 2020 at 1:57pm
| Never worked on a 45 diesel but my understanding is pressure is created on the return side of the diesel system. I would check for restrictions in the return lines and fitting coming out of the pump. The injection pump can pump 4 times more fuel than it uses. At least thats what I was taught back in the early 90's |
Posted By: Larry in NC
Date Posted: 14 Jul 2020 at 2:13pm
| Is it the gasket on the second filter that leaks? Have you replaced the final canister filter to ensure it is not clogged? |
Posted By: Brad-MN
Date Posted: 14 Jul 2020 at 2:19pm
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The secondary canister filter is the one that blows out either the bleeder screw weld or the entire bottom ring, the primary is fine. ------------- 1930 U 1938 A 1941 WF |
Posted By: Larry in NC
Date Posted: 14 Jul 2020 at 3:04pm
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Your set up is different from mine. My tractor has a cartridge secondary and canister final. I am sure some of the diesel experts with have a solution. |
Posted By: injpumpEd
Date Posted: 14 Jul 2020 at 4:03pm
The primary fuel pressure is regulated by the return fitting in the front side of pump head. It should have a spring and plunger to relieve when pressure gets to about 20-30psi or so.
------------- 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! |
Brad-MN wrote:Posted By: Brad-MN
Date Posted: 14 Jul 2020 at 4:20pm
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I did not see a plunger and spring in the casting that I took off the side of the injector pump, but I will take a closer look and check out the extra pump I have laying on the shelf to see if it's the same as what I have....thanks! ------------- 1930 U 1938 A 1941 WF |
Posted By: injpumpEd
Date Posted: 14 Jul 2020 at 6:00pm
It's in the front of the pump head. Some PSB's have a pressure relief spring and plunger in the cover of the transfer pump you're working with. ------------- 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: injpumpEd
Date Posted: 15 Jul 2020 at 7:54am
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By memory, it seems the transfer pump on a WD45D PSB has a spring and plunger on the inlet fitting in the cover. ------------- 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: Brad-MN
Date Posted: 15 Jul 2020 at 8:58am
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Thanks guys...I found the spring and stuck plunger last night once I sat down and actually looked over the pump. I freed it up and oiled it well and hopefully it works from here on out! ------------- 1930 U 1938 A 1941 WF |