Broken tap

[Steve Reist]

Helping my neighbor with his "new" tractor purchase and he
says all it needs is an exhaust manifold stud drilled out.
Wrong! It's a broken tap that some Bozo filled with JB weld
because he probably drilled into a water jacket. Nice job!
Any thoughts on this problem. Heat and a tap extractor won't
budge it. Thanks in advance, Steve

[ken medendorp]

Need to be set up in a mill and machined out with carbide cutter or set up in a EDM machine and burned out.
It is also possible to burr it out with a pencil grinder and a small carbide burr . Good luck

[skidoo29]

ken is right, although if you are going to grind it out be careful if you want to ever use the thread again.
when I first read your post I thought you said a screw was broken, they are alot easier.
if it is a big enough tap you can try using a center punch and hammering it out counter clockwise, the tap that is

warren

[Jeff_G]

Get some dry ice. Pack it in the hole and let it cool the tap. Then using a center punch you can break the tap into pieces and remove it. You can still do it without the dry ice but is a little harder.

[Talon2.5]

yep i'm facing the same deal, awhile back i had a lower unit stud in the mid-section break off, drilled it and the easy out broke off in the bolt :mad:

guess i'll tackle that when i go to fix my tuner that dropped in the mid-section hehehehehe might as well paint everything with a new custom paint job while it's all torn down :D

[Wile E. Coyote]

Skidoos tip is accurate, the tap is a brittle metal and will shatter upon impact. That being said, its a tough job, especially if there is alot of tap buried in that hole. It may not be very easy but usually if you take it to a machine shop they will have one or two tricks up their sleeve to remove it without too much trouble....

[skidoo29]

I am not a big fan of just hammering the tap and shattering it, you usually do more damage than good as I said especially if you want to still use the hole, just try hitting it counterclockwise. I have done too many to count trying to fix apprentices ( and my own) mistakes at my shop. If it is at all possible and you have access to a milling machine or even a good drill press, it is much easier to drill it out with a carbide drill, I wouldn't do it by hand because all you will do is break alot of drills and probably wreck the hole.
remember when you are trying to tap it out patience is definatly an asset.

I have never used dry ice but I suppose if the hole is big enough it will work.
everything depends on whether you want to use that tapped hole after or if you can go to a bigger size after thungs get damaged.

warren

[Steve Reist]

Many thanks guys. I will try the easier methods suggested and
then pull the head if not sucessful. Will let ya know how I come
out. Regards, Steve

[Robert]

You can use a hole saw to remove the metal around it, then fish it out with a needle nose, if it does'nt come out in the hole saw. (Without removing the head)

Probably an Inline 6 or 4 cyl. Not all but most of the time it's the front or rear hole bolting the exh on. The manifold grows in length when hot and breaks it.

It would serve your buddy to go up one bolt size so it won't happen again. Make sure there is room between the manifold and the body of the stud you use.

Those taps are impossible to beat out in the worst case senerio.

Good Luck

[Steve Reist]

Success, I think! Carbide die drill and a center punch. Put a
heli-coil in and new stud and sealed the threads cause they
did drill through the water jacket as I feared. Will put it
back together tomorrow. Thanks again for all the great ideas.
Regards, Steve