Well fiddle sticks

[tenn terry t]

well I brought another cub in a few weeks ago cleaned it up a little only to find this. That's the third from the front sparkplug is this a common place to crack? little dude runs like a sewing machine

[tst]

that is a freeze crack, water was left in it at one time and it froze, that is the thinnest part of the head and they crack there, it can be welded, also the bolster cracks right under the grille, check and see if the bolster has been welded

[tenn terry t]

I don't see bolster cracks yet. I do have one with a crack as you described right blow the grill someone had bubble gummed aweld on it before I got it

[ntrenn]

So....are you up to trying a sealer? I've used them on my 65 successfully...

https://www.amazon.com/Genuine-GM-36346 ... B000QIH3C4

[tst]

where it is welded that is the bolster

[tenn terry t]

ntrenn I don't know what im doing yet I just got this one a few weeks ago and im not in any hurry thank you sir

[Scrivet]

Drain the coolant down below the head.
Wire brush it down to bare metal to about an inch or more on each side of the crack (a wire wheel in a drill works good for this) get as much as you can out of the crack.
Spray it down good with brake cleaner.
Mix up some JB Weld and slather a thin layer over the crack and extend out into the cleaned area.
Let set up for a couple days.
Get on with life.

I've got a Cub I did this to several years ago, still no leaks. If I ever paint it I'll mask off the grey stripe across the head. I kinda like the stripe now anyway.

Edit: I really shouldn't have to say this, but in case it's not self evident, top of the coolant before you get on with life.

[k hutchins]

That #3 plug hole seems to be a weak point. My '48 had a crack right through the hole when we got it from it the original owner in 1960. It had actually been braized. We ran it that way for 20 yrs before it opened up again and I replaced the head.
New heads are available TM Tractor has them for $175 plus gaskets.
Good luck.

[Willy]

I'm not a professional welder, but years ago I welded up a couple of cracked exhaust manifolds and am confident enough in the process to do it again. The trick an old school welder taught me is don't let the cast iron get hot. First grind out the crack just enough so you have good cast to work with. Then just "tack" it back. Make a tack weld, then let it all cool back down to ambient temperature. Make another tack and let it cool. Just keep on tacking and letting cool until your grinding is filled. Just don't get in a hurry or it'll crack again while you're trying to weld it back. Just small tacks is the trick. I did the manifolds over a couple of days. Tack, go do something else for a bit, come back and add another tack.

[tenn terry t]

so are yall saying to weld the crack up in place or remove from the tractor ? if I go to the trouble to remove it ill get another head

[Bob McCarty]

You can do Scrivet's JB Weld repair with the head on (hood off). If it doesn't work the next step would be removal to braze/weld/replace.

[Rob in NH]

A used head isn't a lot of money, if your taking it off to fix it i would just replace it.

[tenn terry t]

yea Rob a mutual friend of ours has offered me a head so I probably just going to change it out just worried about breaking bolts off. Thanks every one

[Stanton]

...just worried about breaking bolts off...

If removing the head, go easy on the bolts. You might try an impact wrench on the lowest setting to ease any stubborn bolts out.

If it were me, I'd be doing the JB Weld fix and let it go...

[Slim140]

Get new grade 9 bolts from McMasterr Carr for the reinstall of the head.