[Guest]

Hope to get ideas on this one. I was taking out the waterpump on my 65 fastback to put in a new hiflow type. Well the top most bolt broke. I got the rest of the bolts of fine and the pump off. So far no problem. I drilled out the broken bolt OK. Then I got clever and decided to tap the hole to re-thread it. So when I put the pump back on it would be just like original Well the dumb tap broke off about 1/4 inches into the hole of what I think is the timing cover.

My only thought is to take the whole thing off and either knock the tap out or take it to a machine shope to EDM out. How hard is it to take that part off? Any ideas for Dumbo would be nice.

 

[tonyswe]

check your tool supplier for a tap extractor, it is a little tool that has 3 or 4 small prongs that goes into the flutes on the broken tap,,sometimes it works if the tap is not totally jammed, if a little piece of the tap is sticking out vise grips usually works. A small amount od heat on the surrounding area helps most of the time. Good luck

 

[midpack]

i wouldn`t hold out much hope for a tap extractor, EDM may be your cleanest bet in the long run
of course I run an EDM dept. so I`m kind of biased

 

[Guest]

Thanks. I will try that. It looks like it is really jammed in there and I don't think I can get any of the prongs from a tap extractor into it. There is no part sticking out to get with the vice grips! Is it a big job to take that part off the motor? Its the part that the water pump mounts to ( timming cover? ).??

 

[rlsteel]

In this circumstance heat is your best friend.A propane torch will work. Robert

 

[midpack]

if you decide to use heat to try to loosen the broken tap, don`t forget the proximity of your fuel system, or you will be applying for a doofus major

 

[Huskinhano]

I've done a lot of tapping in my time. I honestly believe taps get fatiqued after a while and will fail under normal use.

Well, what has worked for me, I take an old centerpunch and shatter the tap. Start at the flutes to reduce the OD size of the tap. Next, try working the tap out tapping on the centerpunch in a couter closewise rotation, like you're trying to unthread it. Taps are very hard and will catastophically fail. I've found this way has gotten me out of some situations. It may not be the right thing, but it works. You may have to run a fresh tap through when do to restore the threads.

This may be a backyard proceedure, but when you're in the backyard, what else are you going to do? *LOL*

 

[Guest]

Thanks! That sounds like something to try that wont cause any more problems. Perhaps if I can shatter it and heat aound it also a bit it may come out. When you shatter it do you just hit the center punch with a hammer real hard? Or is there some trick?

 

[Guest]

I am with Huskinhano. I've been able to get many, but not all, out this way.

Just make sure you are wearing glasses if ya bash it. Taps are very brittle, and the little parts will fly like the dickens.

Good luck

 

[fordnut]

have you tried a small punch and try to gently tap it in a counter clockwise motion. I have always hated to hit a tap real hard...They do shatter....

 

[Huskinhano]

That's it! hit it hard, start at the flutes first to try to reduce the OD of the tap.

I just had to do the same thing a few weeks ago in a cast iron electrical floorbox in the parking garage at work. Had a bear of a time getting the screws out from corrosion, a couple broke flush. Then I had to drill the old srew out and chase a tap through to restore the threads. Yes the tap broke! Couldn't exactly bring the box into the shop. That's how i did it. BTW, use antisieze when you put it back together, the next time you service it, you'll have no problems. I always use antisieze, great stuff, even of gaskets!

 

[Axnjxn]

Be careful. The timing cover is aluminum, and is therefore very soft. If you whack the tap too hard and it doesn't shatter, you are likely to just tear it out of the aluminum, or worse break off the ear the threads are in. If it tears you can go a bit oversized and install a helicoil or keensert.

In this particular case, I would try the heat first. Aluminum has a much higher thermal expansion coefficient than the tool steel of the tap. This means the torch method will be exceptionally well suited for this problem. But be careful, not too much heat, the aluminum will melt or warp pretty easy. I would combine the heat with either a tap extractor, or a reverse drill bit. They are available at mcmastercarr.com.

 

[Guest]

It worked! Thank you all for the good advice. I hit the tap with a punch ( a bunch of times real hard ) And finally shattered it out. Whew! I realized the reason the tap probably broke in the first place was I had the hole drilled too small. I got the rigth size bit drilled it out and tapped ( with a higher quality tap this time ) and it works. Now that this is done I will finish my air condition job and post photos on my web site of the install.