How do you get a broken bolt out of an aluminum intake?

I got an Edelbrock for a SBC and the bolt for the alternator bracket is broken off flush.

 

The old drill and E-Z out route works, with the judicious use of heat. Also if the manifold is off the car, stand it up and heat the manifold just hot enough to melt candle wax. Let it run down and set up. Makes the EZ out method much easier.
Steve

 

That might be rough, possible gavanic corrosion.

Worst case, a couple of fresh titanium drill bits and WD40 for lube and you can drill it out and tap the threads.

 

If you can Mig Weld a Knot onto the Broken Bolt then vise grip it out,the heat from the weld helps loosen it,has worked for me more than once

 

Carefully!

 

This is truly the best way, STAY AWAY FROM THE EASY OUT! A broken easy out is a bigger pain in the ass than it is worth. Worse case scenario is a left handed drill bit that is a smaller size than the bolt you are extracting. Eventually it'll loosen enough to bac it out. If not incrementally go up in size until you can re-tap it.


Best of luck and Happy Holidays,

Tim

 

E-Z Out works most of the time.

 

Mig weld a washer to the broken off bolt, then weld a nut to the top of the washer. before it cools use a wrench to remove.

 

yep works almost all the time. If it dont, weld another washer on and another nut and remove.

 

I use hex nut since it is flush I center the nut on the bolt turn the heat up on the wire welder and weld in the center of the nut let it cool just a minute and then put a little heat around the area of the bolt, if you try to turn the nut when hot it will just break off may have to does this a few times but I have had good luck this way

 

I use left handed drill bits. Carefully drill the center with a small bit about 1/8" in size. Then increase the bit size until the bolt unscrews itself.

So most folks don't have left handed bits so do the same with regular bits until you get the hole out to the treads. Then try to spin what is left out with a sharpened punch and small hammer. If that fails then just drill out the rest and pop a Heli-coil in there.

If you have a welder I'd give that a try. Sounds like a great idea.

 

Getting a bolt to thread out of aluminum is one of the most difficult. What I do is; file the broken bolt flat, center punch, drill starting quite small and working up till you can see the threads showing, then start alternating between a tap and a pick in an effort to "pik" the threads out without damaging the part. Obviously, the better your hole drilling is centered, the better this works. If by the time you get all the steel out of the hole in the casting you realize the threads are shot, it is then a simple matter to heli-coil it, but I honestly have only had to do that in some of the cases where someone else tried to get the bolt out before bringing it to me.

A word of advice; never use bolts in aluminum, use studs and nuts. Saves headaches later!

 

WELD THE WASHER ON TO THE BOLT, THEN WELD A HEX NUT OFF CENTER, (FOR LEVERAGE) then tap manifold near bolt as you slowly turn hex nut with 6 point socket or box end wrench.. try agin, and agin..

works well

 

That's it. Best method I've found.

Bob

 

mig welding a nut has never failed me yet ,and i am up in salty rust country

 

Wow guys,thanks for all the advice! I'm suprised the bolt could break at all in aluminum without stripping the hole first.

 

Always use Never-seize on bolts in alum. Actually I use never-seize on all bolts/studs on the outside of my engine. Never had one seize/break.

 

I just took a broken bolt out of a weiand intake with my left handed drill bits. They have inexpensive ones at my local menards, and I have used them several times on broken bolts.

 

The biggest problem with EZ outs, aside from them snapping off, is that they force the walls of the broken bolt outward and actually make it tighter in the hole. Left handed drill bits or progressively going bigger until you see the threads and retapping seems much better. But I have used the welded nut routine more than once and it does work.

Don

 

Once you get the broken bolt out, replace it with grade 8 or stainless steel bolts.....

 

1/4 20 broken of below the surface. The broken bolt was built up above the surface with weld from my Mig machine. So that a nut could be welded to the broken part.



A nut gets welded on and backed out. Piece of cake on an aluminum manifold The dissimilar metals make it easier.


It looks worse than it is. Tap cleaned it up just fine but a Nutsert would repair it even better if necessary.

I don't care for easy outs. I've had trouble with them breaking too. Just my personal preference.



After glass beading and powder coating.

 

Tommy , This should be put in the tech archives. Great post!

 

Ditto, the left hand drill bits.......They're easily available, and most of today's air powered drills are reverseable. I'll add, dril it as far as possible, then clean it out, and go with helicoil and anti seize.

4TTRUK

 

What he said ^^^^^^^^^

 

Probably the old bolt bottomed out, causing it to break ... watch out for depth of new bolt ... and retap threads before re-install .

 

Lotsa info here,some good, some not so good, IMHO. I have been a machinist for over 45 years, so I've seen just about all these methods used, all with varying degrees of success.
I still have a shop I still have an occassional job to do for paying customers, sort of helps pay the utilities, taxes, etc. I guess you can say I'm only semi-retired.
And if you bring in the job unmolested, I or any other job shop machnist worth the title machinist, will use those years of experience to determine which method to use. It's hard to say which without to use unless hands on.
But I will say the method most likely to fail, often with disastrous results, is the "Easy Out", or screw extractor. And when you drill that hole with an eyeballed, hand held drill and get it off center and then break an extractor off in the crooked hole, you got BIG TROUBLE.

 

All of the above are great ideas that work ( except the E-Z out)....you just gotta add patience.

 

Some great tips here!!! One thing I use if you have time on yourside kroil is the penitent on the market! Soak it with that it works!

 

Still find it hard to believe some folks think WD-40 is a lubricant or a penetrating oil. WD means Water Displacement thats the function of WD-40. For penetrating oil I use PB Blaster.

 

It is design intent to have the fastener break. It is more practical, drilling and using an EZ out on a broken fastener than it is to create a larger threaded hole. In some situations the option to re thread larger is not available. It is good design to makes sure that failure occurs on the bolt. This can be accomplished through thread engagement length. Design selects a thread engage length so that the total amount of engaged thread is stronger than that of the bolt's minor diameter.

In a case where you have a steel bolt threading into an aluminum piece, Design specifies a much larger thread engagement than they would if the threaded hole was in a steel. Controlling thread engagement length helps ensure fail occurs where intended.