Cub coolant leak and head bolt locations

[workingfarmcub]

Hello

Have been fighting my grandpas cub for almost a year now. Quit on him while running and was incredibly hard to start. Long story short is it had fairly low compression and I think the magneto coil might have been weak. Didn't really have time myself to work on it and let a neighbor convert to external coil and refresh some of the internals. Runs pretty good now.

Well he ended up reusing the head bolts and I dont think any sealant was used on the gasket or bolts. Think im getting coolant leaking out of the front center head bolt and coming out the air cleaner bolts then running along the top of the exposed bit of head gasket. May also be leaking from between the gasket and head hard to tell. Thinking of checking for warping, getting some new head bolts, gasket and sealants and try to seal it back up. Are the red bolts in the linked picture the longer ones? With green being the shorter? Here are the pictures.

[Barnyard]

The long bolts are used in the highest point of the head and the short bolts are in the lowest point of the head.

[ScottyD'sdad]

Be sure to put non hardening sealer on the bolt threads, since they go into the water jacket, and can leak.

Ed

[tst]

the short head bolts are a special size, be sure to get the correct ones, use a spray copper gasket sealer on the head gasket, if you have a gasket that is blue on one side do not spray the blue, use Teflon sealer on head bolts

[Jim Becker]

Just what does "refresh some of the internals" mean?

My first pass would be to take the lazy man approach:
- drain the coolant.
- go individually to each head bolt, loosen it then bring it back to slightly snug.
- go to each head bolt in head torquing sequence: remove, clean, add thread sealant, reinstall to slightly snug.
- retorque the bolts by the book; in steps, in sequence.
- refill the coolant.
- run the engine to warm it up then retorque by the book.

Use it to see if the problem is fixed. If it still leaks, then pull the head and do the larger job.

[staninlowerAL]

Seems like I remember a post from a while ago that cautioned about the bolts for the mounting bracket for the air cleaner penetrating into the water jacket. Wouldn't cause any problem to put sealer on those bolts also. JMHO

[workingfarmcub]

Just what does "refresh some of the internals" mean?

My first pass would be to take the lazy man approach:
- drain the coolant.
- go individually to each head bolt, loosen it then bring it back to slightly snug.
- go to each head bolt in head torquing sequence: remove, clean, add thread sealant, reinstall to slightly snug.
- retorque the bolts by the book; in steps, in sequence.
- refill the coolant.
- run the engine to warm it up then retorque by the book.

Use it to see if the problem is fixed. If it still leaks, then pull the head and do the larger job.

By refresh I meant basically a cleaning and rering. He said the compression was low which was my guess as to the hard starting as I had adjusted cleaned and checked almost everything else. He had said was in good shape but had a lot of carbon in the head and plenty of sludge in the oil pan. Piston rings were also carboned up and all lined up for some reason. Not sure if that happens over time or if someone didnt know what they were doing.

Will pick up some sealer for next weekend. Whats the best method to clean out the threads in the block? Also, doing this approach I should start loosening with the last bolt in the torque pattern right?

[Barnyard]

Before tearing it down for a ring job, run it with Sea Foma for a couple of months. I picked up HP and torque after running mine with a sickle mower for a couple of months.

[staninlowerAL]

Before tearing it down for a ring job, run it with Sea Foma for a couple of months. I picked up HP and torque after running mine with a sickle mower for a couple of months.

Bill, Reading all the above, I think he has already done this. Problem is water in unwanted places. Any comment on the post I wrote about the air cleaner bracket bolts? Figured you would know. TKS Stan

[Barnyard]

Any comment on the post I wrote about the air cleaner bracket bolts?

Stan, I haven't run into that myself.

[Bill V in Md]

Are the red bolts in the linked picture the longer ones? With green being the shorter?

Yes

[Glen]

Hi,
If you do what Jim said above, I would suggest that if you have antifreeze in the cooling system, I would use a garden hose with a nozzle, and wash down each head bolt hole, after you take the bolt out, to wash the antifreeze off the threads.

Antifreeze leaves a sticky film on metal, the sealer should have bare metal to stick to.
Leave the drain plug out from under the radiator when washing the threads.
After washing them, you could use compressed air down each hole to dry the threads some.
Wear your safety goggles when using the water and air.

Wash and dry the bolts too, if you use the same bolts again.

I would tighten the head bolts gradually, in steps of about 20 ft lbs, then 30, then 40, then 45.
The torque sequence is in the link below.

Stan, the 2 bolts holding the air cleaner on the head shouldn't need sealer.
I've read on here about them leaking before.
The leaking would be caused by the head bolt where the 2 bolts are needing sealer at the bottom of it's threads.
The 2 bolts holes evidently go through the side of the hole in the head for the head bolt.
If the head bolt threads leak coolant up into the upper part of the bolt, then coolant can run out the 2 bolts for the air cleaner.

Below is a page from the Cub service manual, showing the head and the head bolt torque sequence.
The bolt is number 11 in the pic.

http://farmallcub.com/rudi_cub/www.clea ... -01-14.jpg

[staninlowerAL]

Glen, that makes sense. I remember this coming up when I replaced the head on my 154 Loboy several years ago but just couldn't remember any details. Next time I have access to a head that is removed I plan to examine it a little closer. Thanks.

[Jim Becker]

Whats the best method to clean out the threads in the block? Also, doing this approach I should start loosening with the last bolt in the torque pattern right?

Reverse of the torque pattern is the safest and most conservative way to loosen them.

On the cleaning the threads in the block, running a tap into them would be ideal. The catch is the length of a tap vs. the thickness of the head. In other words, you probably don't have a tap long enough to do the job with the head in place. If you can't tap the ones where the longer bolts are, don't do any. So your best option is to do as Glen outlined. If you end up having to pull the head, use a tap at that point.

[workingfarmcub]

Waited till warmer weather to tear into this. Ended up going with new bolts, new gasket, chased and cleaned the threads and flushed out the block and radiator. Definitely has some rusty water flowing out of both. Hopefully get the rest of it back together this weekend and get it warm.