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maxwell18 · 11-06-2016, 02:07 PM

Just wondering if anybody has dealt with small leak in cylinder head on cummins 400hp. I was trying to drill out a stud that broke off that held the turbo shield that covered the turbo. It looks like something Monaco added. One bolt failed in the past and then the bracket broke and the shield fell on the engine and was rattling made me look and find it. In my attemp to fix it I checked the other 2 other blank holes just like the one I was trying to get the bolt out with a eazy out and the drill slipped not being centered, caused me to just drill out the hole and was going to put a heli coil in it. I only drill half the distance down the hole and got anti freeze. I stopped and I am still crying. Any ideas?
Thanks

Big Bear Local · 11-06-2016, 02:23 PM

JB weld.............

powderman · 11-06-2016, 02:27 PM

Could you finish drilling, put in the helicoil, then a stud. Maybe need some sealer.

IC2 · 11-06-2016, 02:37 PM

I would be surprised if that bolt/stud passes into the water jacket and that you really didn't drill through the jacket - and the real reason it broke off was rust. Think small block Chevys and ancient Flathead Fords as a ready reference to that kind of design. Bolts in water cooled automotive engines have often been 'immersed' in water. Drain the engine, Helicoil it with a stainless piece, seal the bolt and enjoy.

pointrow · 11-06-2016, 02:37 PM

Just complete what you set out to do. Lot of plugs into water jackets with no problems.
I would use Permatex on the treads to assemble.

good luck

pointrow

mel s · 11-06-2016, 02:42 PM

Quote:

Originally Posted by powderman

Could you finish drilling, put in the helicoil, then a stud. Maybe need some sealer.

powderman

Sounds like a solution to me.

TarasParents · 11-06-2016, 02:44 PM

Should work, just wondering if the diameter of the drilled hole would allow metal chips from the threading into the cooling system and harm the water pump. Sounds like the drill metal fragments were flushed up with the coolant leak. Other than that, heli coil sounds like a good fix.

Don't let me throw cold water on your idea.

twinboat · 11-06-2016, 03:22 PM

Any chips will settle in the block near the drains.

**JohnRR** · 11-06-2016, 04:02 PM

Either drill and tap oversize or continue on with the Helicoil procedure, don't forget to use a suitable sealer on the threads.

Over the years many manufactures have had threaded holes into water jackets and oil passages.

You may have to drill the bracket out a size if you go the oversize bolt route.

Edit;
While using the refresh button I did not see the previous same replies, sorry about that.

twinboat · 11-06-2016, 04:31 PM

Another tip is to pack the flutes of the drill with grease. Most of the chips stick in the grease.

maxwell18 · 11-07-2016, 08:54 AM

Thanks for all the information and help. After resting and thinking and studying
pictures here what I have. I drilled way off center but still inside the original hole. I good portion of the bolt is still there. The hole I drilled is pretty round but did not get all the bolt out. Should I just try and tap the hole I got leaving part of the original bolt there or try and drill the old bolt completely out tap or helicoil? I measure the hole depths with 2 other holes in line and this hole is less then half the depth and for sure into to the water jacket? I would put the pictures on here but I don't know how. The 74 years is catching up with me.
Thanks again

Papa_Jim · 11-07-2016, 09:26 AM

You have to drill that out. Slowly increase the size of the drill bit until all that is left is some of the bolt on one side of the hole. You may have to be a little creative, make a little chisel to tap that piece of bolt out. Then helicoil with sealant and you should be good to go!

Jim

IC2 · 11-07-2016, 11:10 AM

Drill until you are just into the threads of the engine casting then use a pointed punch to loosen things - tapping it reasonably firmly, not 'whanging' it with your biggest hammer. Use a little spray like PB Blaster or better yet, Areo-Kroil if you can find it locally - W-D 40 is totally worthless now that the EPA has gotten into their good stuff. A little direct heat with a propane torch wont hurt. Once you think you have loosened it, an E-Z Out might just do the job - but don't horse that tool. If you break an E-Z Out, about the only thing that will remove it is an EDM metal disintegration machine along with big bucks for labor.

38Chevy454 · 11-07-2016, 11:20 AM

if I understand correctly, you still need the threaded hole for the mounting of the bracket? If so, some thread sealer should work. If the hole is not needed for mounting, I would tap it NPT (aka pipe thread) and put a plug in, with a bit of thread sear of course.