Allis B oil pump failure?
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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=163617
Printed Date: 15 Feb 2025 at 7:51am
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Topic: Allis B oil pump failure?
Posted By: Tgtack
Subject: Allis B oil pump failure?
Date Posted: 13 Aug 2019 at 1:32pm
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So was driving the B the other day, and she just quit in middle of road. Never done that before. Fuel in tank and fuel was on, so tried cranking it over (is hand crank). Engine was "tight" first couple turns, then loosened up and fired right off. Checked oil gauge and zero pressure. Immediately shut it off and trailered home. Plenty of oil and clean, pulled oil filter and spun engine over, no oil. Tried reprime, still no oil. At this point, figure was oil pump failure. Anyone have a picture of the camshaft end so I can see what the drive for the pump looks like? From what I can tell, is some type of pin. Also looking for pump source. Am aware of rebuild kits, rather get one already to install. Any other thoughts on possible failure mechanisms of no oil pressure before I split it in half? ------------- 1939 AC Model B, 1952 AC Model G, Case 195, numerous Wheel Horse, Hit Miss Engines, currently looking for a AC B10 garden tractor |
Replies:
Posted By: Gerald J.
Date Posted: 13 Aug 2019 at 5:26pm
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Shop manual might help: http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf" rel="nofollow - http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf Gerald J. |
Posted By: Tgtack
Date Posted: 13 Aug 2019 at 5:46pm
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Thanks much for the manual, will help a lot. Don't see any discussion of the drive pin as far as possible replacement. Hopefully can tell once pan is off. ------------- 1939 AC Model B, 1952 AC Model G, Case 195, numerous Wheel Horse, Hit Miss Engines, currently looking for a AC B10 garden tractor |
Posted By: Dick L
Date Posted: 13 Aug 2019 at 7:18pm
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Here is a picture of the pin inside the camshaft along with a picture of the pump stem the fits over the pin. A new pin can be installed without removing the camshaft. It is not easy but can be done if your hands are not the size of a baseball glove. I took these pictures for a person that did get a new pin in.   
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Posted By: Tgtack
Date Posted: 14 Aug 2019 at 1:49pm
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Dick, is the pin tapered or an interference fit? What holds it in? Any idea where a new pin cab be purchased? ------------- 1939 AC Model B, 1952 AC Model G, Case 195, numerous Wheel Horse, Hit Miss Engines, currently looking for a AC B10 garden tractor |
Posted By: Dick L
Date Posted: 14 Aug 2019 at 3:25pm
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I have always replaced them with a roll pins. It is not tapered. If you try to replace it without removing the camshaft you have to retrieve the broken pin to keep from it getting in the crankshaft and camshaft gears. That will be the biggest challenge. Sometimes when the pin breaks it gets pushed out some to where you can pull it out on the one side. The other side can then get punched out. They seem to have been peened on both outside ends some to hold them in. You will have to check to see how your luck is running! If you can get it out you will have to grind a taper on the end of a roll pin to get it started. The roll pin can stick out some but not a lot. Maybe a eighth of an inch each side. You will need to use a smaller pin to make sure you have the pump lined up to drive the roll pin thru the slot in the pump stem using a hand crank. You will be able to tell if you can replace it in the tractor after you remove the pan and look and feel up under the camshaft end where the pin is located. |
Posted By: Steve in NJ
Date Posted: 14 Aug 2019 at 4:56pm
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Make sure the oil screen isn't all full of gunk or RTV. They plug up easy! Steve@B&B
------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife |