cracked B block
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=163161
Printed Date: 09 Apr 2026 at 11:10pm
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Topic: cracked B block
Posted By: festus51
Subject: cracked B block
Date Posted: 27 Jul 2019 at 9:36pm
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I tore apart my B engine today searching for the reason why I am getting water in the oil. I was hoping for freeze plugs in the head but they were good. Took the head off and found a crack between # 1 and #2 cylinders. So my question has any one successfully repaired a cracked block at this location? ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |
Replies:
Posted By: SteveM C/IL
Date Posted: 27 Jul 2019 at 9:44pm
| Cracks at the top of the block have no ill effect. Oil and water are sealed at head gasket. Cracks in the bottom web between cylinders are a different story. |
Posted By: festus51
Date Posted: 27 Jul 2019 at 9:47pm
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I have not taken pan off to look at bottom , but it has crack at top and it is mixing water and oil ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |
Posted By: CTuckerNWIL
Date Posted: 27 Jul 2019 at 10:22pm
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The best way to find how water gets in the oil, is BEFORE you take the head off. You remove the oil pan and the rocker cover and pressurize the radiator to 7 psi. With the head off, about all you can do is pull the sleeves to see if there is a crack down where the o-ring seals, or a sheared o-ring. Also, the only way to tell if the core plugs are good, is to pressurize the coolant system and look at them, or to remove them and replace them. You cant tell a thing by looking at them. ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: WF owner
Date Posted: 28 Jul 2019 at 5:48am
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Just because the "core plugs" (Dick L would be proud that I didn't call them frost plugs!) look good, they still may be leaking. For the couple dollars each they cost, it's pretty inexpensive to replace them. I'm betting that they will look not look so good when you get them out. As others have said, cracks between the cylinders are very common and are sealed up by the head gasket. The most common coolant in the oil is caused by leaking core plugs n the head, head gasket, crack in the head, holes eaten through the sleeves or O rings on the sleeves leaking.
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Posted By: Dick L
Date Posted: 28 Jul 2019 at 7:48am
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The only thing I have to add about the cracks between the cylinders that the head gasket seals is, consider the crack you see around the outside of the sleeve and wonder why it does not leak. If you find small amounts of waster laying in and around the core plugs on top of the head on a running tractor the core plugs will be the culprit. I put pictures on a few days back of a head I could not see where it was leaking. I knew it was the only way the water could get there so I took a torch to it and found it. We always have had people that wanted to find the source some other place because of the fear of installing new plugs so I took a picture and posted it. This picture was taken in 2007. 
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Posted By: ryanschott
Date Posted: 28 Jul 2019 at 8:24am
| I’ve tore apart a lot of b or c motors like yours and I have not “I think “ found one that is not cracked so a little crack there won’t hurt anything between the tops of the cylinders |
Posted By: festus51
Date Posted: 28 Jul 2019 at 9:13am
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thanks for all your input, I will change core plugs and put it back together Hope for the best. ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |
Posted By: Gerald J.
Date Posted: 28 Jul 2019 at 9:49am
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Welding an iron casting is difficult, trying to weld a crack usually adds more cracks near the weld. There is a company at Nevada Iowa that is successful at welding cast iron engine blocks. They heat the whole block almost to welding temperature and then weld the crack and cool the block gently to prevent more cracks. They also repair cracked heads. Their name is Midwest Cylinder Head, 1700 W F Ave, Nevada 515-382-2791. Gerald J. |
Posted By: SteveM C/IL
Date Posted: 28 Jul 2019 at 1:37pm
| For everyone in the future looking for coolant leaks.....remove the pan and valve cover and pressurize the cooling system. Give it time and look for leaks before you tear anything apart. If you have a leak,it show up under pressure and pinpoint where the problem is.Otherwise you are shooting in the dark hoping you addressed the problem and may well miss it. |
Posted By: DiyDave
Date Posted: 28 Jul 2019 at 6:17pm
Keep checking for leaks, over a period of time, let the tractor sit, a while, and loosen the oil drain plug, coolant will be in the bottom of the pan, and will wick through the threads of the plug, before oil will drip out. For small leaks, try Blue Devil block sealer. follow the directions on the label. It contains water glass(sodium silicate), which forms a shell against the leaky surface...
Watch at about 4:30 of this video, automotive uses, explained... [TUBE]IXQM8nheRv0[/TUBE] ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: festus51
Date Posted: 28 Jul 2019 at 6:49pm
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very informative video Dave ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |
Posted By: festus51
Date Posted: 06 Aug 2019 at 4:33pm
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Drained the oil pan and got at least a gallon of pure water before milk chocolate oil came out. found a block close to home for $50, bought it and will rebuild the engine. Then I know it is good. ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |
Posted By: WF owner
Date Posted: 06 Aug 2019 at 4:39pm
...IF the block you bought is good.
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festus51 wrote:Posted By: littlemarv
Date Posted: 06 Aug 2019 at 9:07pm
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Here is my experience, maybe it will help someone else. https://www.allischalmers.com/forum/water-in-the-basement_topic143252_post1185340.html?KW=water#1185340" rel="nofollow - https://www.allischalmers.com/forum/water-in-the-basement_topic143252_post1185340.html?KW=water#1185340 ------------- The mechanic always wins. B91131, WC23065, WD89101, CA29479, B1, Early B10, HB212, 416H |
Posted By: festus51
Date Posted: 06 Aug 2019 at 10:39pm
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Well WF I asked and was told no cracks. When I get it home and if I see a crack it will go back to original owner. I will believe the young man is trust worthy enough to not lie to me at this point in time. ------------- We the unwilling Led by the unqualified Doing the impossible for the Ungrateful |