Repairing a cracked block

[Don Rudolph]

Yesterday I picked up a 500 with a cracked block. The crack is an L shape about 4 inches by 6 inches. My question is should we use JB Weld or try the new super duper cast rods that are $10 a piece to repair the crack. It currently has some sort of epoxy patch. Thanks, Don

 

[rankrank1]

I would drill each end with an 1/8" drill bit to stop the crack from spreading and then braze it myself as brazing is the closest thing there is to a foolproof, strong, permanent, low cost repair on cast.

Stick welding cast can work but can also cause a big mess and sometimes even does more harm if not done right. Some cast base metals just do not stick repair well regardless of the rod you use. Most of the experts recommend using a torch and a cast filler type rod if you dead set on welding it. Even then lots of special procedures need followed for any hope of success.

Lok-stitching is also an accepted repair method and does not involve welding or heat at all so it is the accepted done right repair on rare and expensive blocks. Basically involves drilling holes in the cracks and tapping and installing special threaded plugs. You keep repeating and overlapping until sealed.

 

[casecollectorsc]

I have a SC that someone made a steel patch and drilled and threaded holes and cap-screwed it to the block. Never see it leak a drop.

 

[oldproudvet]

I totally agree with the above. If brazing, try to preheat with a rosebud, before the brazing tip. Cast really absorbs heat and I've seen cracks and fissures develop
from an intense tip in one localized spot. Will work great in a block like that. Pressurized blocks I'd lean toward the stitch system.

 

[Tubacase47]

My CC has that type of repair too and it does not leak.

 

[Den N Ms]

Don,If it is worth fixing it is worth doing it right.I would use Lock n stitch to repair it.Electric welding is about the worst method for repairing a cracked block(without a huge oven to put it in)you can cause more damage than good.J B weld might hold for a while but not forever and looks bad .A metal patch bolted on with a gasket will work but don't look good.Brazing with acetylene torch will work but it takes a lot of preheating and a very slow cool down to keep from cracking again.

Good info, http://www.locknstitch.com/cast-iron-welding.html
Lock n stitch,

 

[Richard G.]

Don, I had an old 50 Chevy pickup I bought for $45. It had a crack all the way down the carb side. Just for fun, I veed it out and put red high temp silicone in the crack after cleaning it very well.
Darn thing ran for years on the farm without leaking.
The silicone was flexible enough to move with the block when it heated and cooled.
Richard in NW SC

 

[1370rod]

Don the JB weld would not work the greatest for a exterior pack like that, I think it would be a short term fix. Our local machine shop would plug cracks like that and when finished with some touch-up grinding and a little paint it was hard to see the repair. I don't know if it is a practice still done, Rod.

 

[tractorguy2]

I have a Case sc. The block was welded when I bought it in 1988. I had the tractor for two days before I noticed the left side water jacket had been welded. Looks to be stick welded. Has not leaked yet. The crack is in the shape of the letter "E"

 

[01gentdc]

DONT ATTEMPT TO WELD, Don , jb weld wont work but a short time , like others say ,, go to a lok stitch method ,, it worx very well, there is guy in Buffalo Ky that can stitch a blok back even if a baseball hole is there and the piece is gone ,. he simply very meticulously fits a pc of 3/8ths steel rite perfectly into the cast hole and lock stitches it,,.

 

[Felixt]

I have a VAC with a crack behind the carb. It was welded years ago and has now started to "weep" pretty bad. Looks worse than anything probably. Would the engine have to be tore down for them to repair it or would it be able to be done in the tractor? I am near Buffalo Ky, do you have that guys contact information DC?

 

[centash]

My Dad repaired a couple of D Cases like that. Their cooling system was non pressurized so that made a big difference whether it leaked or not.

Ben

 

[standard fan]

(quoted from post at 15:14:30 01/10/16)
Yesterday I picked up a 500 with a cracked block. The crack is an L shape about 4 inches by 6 inches. My question is should we use JB Weld or try the new super duper cast rods that are $10 a piece to repair the crack. It currently has some sort of epoxy patch. Thanks, Don

I don't mean this to be offensive in any way but you might as well ask what is the most inexpensive method for absolutely destroying my hard to get antique tractor block. This question always leads to a terrible amount of misinformation on possible solutions, from people who have never actually attempted to repair a cracked block in their lives.

Unless you are a very experienced welder I would not even consider trying to weld it yourself. I am a welder by trade and was taught by a welder who had over 60 active years as a welder, who repaired heavy equipment back in the day when every thing was made of cast. His preferred method and mine by default was to weld the block in place with a ferrous road from Lincoln or a Ni rod if the Lincoln rod wasn't available. I have multiple tractors in my collection repaired that way that are still going strong. This is a very time consuming job as without pre and post heat you can only weld a very small bit at a time and you have to peen the weld as it is cooling.

While brazing is a very good method for repairing a casting like an axle it should never be attempted on a block. If you can pull the block off and bring the whole thing up to an appropriate temp then oxy cast rod would be a much better option but again the whole block has to be brought up to temp then brought back down slowly. Trying to use a torch on a block will only turn a small crack into a very big one heading in multiple directions. Too many times has someone brought in a crack that some "expert" had attempted to weld with a torch without the proper pre/post heat.

Like many have said the best method for someone who is not an experienced welder is the lock and stitch method, it can be a little costly but in the long run it may save you a lot. I wouldn't even recommend having it welded unless you can see verifiable proof that the welder is both competent and experienced in block repairs there is just far to much to go wrong.

 

[jicaseman89]

dads 400 block cracked behind carb drilled four holes tapped 5/16 threads chunk of intertube from a tire blue silicone put a 1/4 inch flat plate overtop never leaked yet.
i helped a friend weld a 730 diesel block about the same spot worked good doesnt leak
loren

 

[01gentdc]

502 645 7444,,. rons cracked block ,, buffalo ky ,,. you can google him ,,. great fella ,.

 

[Felixt]

Thanks GentDC i will give him a ring.

 

[L.Fure]

(quoted from post at 23:14:30 01/10/16)
Yesterday I picked up a 500 with a cracked block. The crack is an L shape about 4 inches by 6 inches. My question is should we use JB Weld or try the new super duper cast rods that are $10 a piece to repair the crack. It currently has some sort of epoxy patch. Thanks, Don

Don,
I bought a DC some years back that had a crack in the block. It was even heaved out a little, enough to catch my finger nail when I scratched at it. It leaked pretty bad, and I had to drive it eight miles to get it home. I had my dad with me to drive behind me with the pickup, and I asked him what I should do? He jumped in the pickup and went down town. When he came back he had two cans of ground ginger. He dumped that in the radiator, topped it off with water, and told me to get going. When I got far enough out in the country I stopped to let out some coffee. The crack was dry as a bone. It was still cool enough at night to freeze water, so I drained the block when I got home. Used the tractor a few times and had to fill with water and drain each time. The block never leaked. Later on I bought a new water pump for it. That also leaked, and was the reason I never filled it with antifreeze. Anyway, that crack never leaked in all the time I owned the tractor, and I never babied it. I traded the tractor in for another piece of equipment after some time. I found it in someone's collection a few years later. The crack was still there and hadn't been leaking. I asked the new owner about the crack in the block, and he thought it was funny that the crack never leaked. I just grinned and went on my way.

 

[CKain(MI)]

Several years ago I had a good welder fix a crack in my DC's block. He put in a nice effort and it 'may' have worked. Then I took off the valve cover and found a big bulge and cracks in the head !! Gave up, found an whole engine(uncracked) for $200. !