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View Full Version : Freeing a stripped drain plug


elshauno
04-06-2007, 09:14 PM
I have a stripped drain plug that is stuck on. Ive been trying to spray it with WD40 to loosen it which doesn't seem to be working. I tried a stripped bolt kit which just totally rounded the bolt. So now all I can think of is taking a torch lightly to the drain plug heating it up and going at with heavy duty vice grips. Or maybe angle grinding down the sides of the bolt to reestablish the edges then doing the aforementioned torch with a wrench. If that doesn't work I guess I'll have to drill but I don't really want to risk putting shavings in the engine. Any ideas throw them my way. Thanks

Gmgbo
04-06-2007, 09:21 PM
what kind of engine?

khouse
04-06-2007, 09:27 PM
Visegrips. Not the knock off ones but the real ones. I have grinded flats on bolts and nuts on more than one occasion.

xcopterdoc
04-06-2007, 10:32 PM
pipe wrench

DiyDave
04-07-2007, 06:45 PM
First try Kroil penetrating oil. Seems kinda weird that an oil plug gets stuck, doesn't it. If the Kroil doesn't work, punch the plug with a center punch, then drill through with 1/8" bit, then keep drilling through with larger bits, till you can get the smallest pipe type easy-out in the hole. Then put the easy out in with a couple of taps of a hammer. Then use an air impact to remove the plug. By the way, when that 1/8" bit breaks through the plug, you are going to get some oil on your hand, sleeve, drill etc, so be prepared with a pan, rags, etc. After plug is out, clean around the pan with a magnet wrapped in a paper towel, to remove stray chips.:) :)

SLR
04-07-2007, 10:10 PM
How about a little heat 1st & then the pipe wrench.

hdtvluvr
04-07-2007, 10:54 PM
Why does everyone try heating bolts, etc. that are stuck? It seems to me that heating a stuck plug would do 2 things since heated metal always expands.

1. The plug would expand causing it to be bigger and thus tighter in the hole.
2. The metal around the hole would expand causing the hole to shrink in size - also making the plug tighter.

Why not try a little dry ice? This will cause the plug to shrink, as well as shrink the metal around the hole. If the metal around the hole shrinks, the hole will be a little larger. plug smaller, hole larger would seem to make it easier to remove.

What am I missing?

BTW, I was told about this trick when I was trying to replace a hub on a JD garden tractor. Cooling both allowed the hub to simply slide on instead of me trying to hammer it on and possibly damaging the axle / transmission.

SLR
04-07-2007, 11:05 PM
But i think using the heat method actually causes tiny movements to the froze part,thus starting the removal proccess a tinnsy fraction.

Last year i did my balljoints,but found the new balljoints a hair to big so into the freezer the new ball joint went for 3hours,then heated the control arm abitwhere it goes into. End result: balljoints required very little tappage to seat.

mini14
04-08-2007, 10:39 AM
if u got an impact, get yourself a set of stripped bolt head extracters from sears or whoever else. thats what is used to remove wheel locks when the key is lost. when u finally get that off do yerself a favor and put a brass finger drain plug on it and u will never ever have a prob. again...i have em on ALL my engines.

Grassmechanic
04-08-2007, 12:52 PM
Why does everyone try heating bolts, etc. that are stuck? It seems to me that heating a stuck plug would do 2 things since heated metal always expands.

1. The plug would expand causing it to be bigger and thus tighter in the hole.
2. The metal around the hole would expand causing the hole to shrink in size - also making the plug tighter.

Why not try a little dry ice? This will cause the plug to shrink, as well as shrink the metal around the hole. If the metal around the hole shrinks, the hole will be a little larger. plug smaller, hole larger would seem to make it easier to remove.

What am I missing?

BTW, I was told about this trick when I was trying to replace a hub on a JD garden tractor. Cooling both allowed the hub to simply slide on instead of me trying to hammer it on and possibly damaging the axle / transmission.


Dry ice??

I have NEVER encountered a broken/stripped bolt or stud that cannot be removed with heat. Heat em' up cherry red. Even old farm machinery that is rusted up tight. Even exhaust manifold studs. An oxy/acetylene torch is one of the most important tools one can have.

Heat to remove. Cool to install.

SLR
04-08-2007, 04:33 PM
Heat to remove. Cool to install.

==
I like that lil'speech!

terrapro
04-08-2007, 04:46 PM
heating also lessens the chance of breaking the bolt or messing up the threads. cold metal breaks which is why you do not use dry ice to chill the bolt

freddyc
04-08-2007, 05:42 PM
The drain plug is essentially a bolt. The pan (or engine) is essentially a nut.

Heat the pan (or engine) slightly right around where the drain plug is. Use either the real vise grips or a small (14") pipe wrench.

As you try to loosen the plug, tap on the end with a small hammer.

The combination of heating the nut to expand it, a firm grip from the pipe wrench and the added value of the impact action of tapping it while you try to loosen it will be your best chance. If its rusty or been in there a while, some really good penetrating oil (not WD 40) should be applied first and let sit a few hours to sink in.


With regard to your comment on dry ice, you're correct. But in this regard....

If you have a bolt stuck in a nut or better yet, some taper fit (which is actually called an interference fit) then you are correct on your assumption of heat and cold. By applying heat just to a bolt (a solid cylinder) it will expand.

This of course would make the condition worse. By applying heat to the nut and cold to the bolt, the nut would expand and the bolt would contract. This is the best scenario if it were doable in real world situations. The better trick for small objects (which you don't have) is to throw both of them in the freezer. Then after their cold enough, take a torch and just heat the nut...it will expand and if you turn it quick enough, the thing will loosen up.

The answer about just heating is mostly true, but it also comes back to the coefficient of thermal expansion on both parts. In short, you're never just heating the plug.... the area around it is also getting heated up by conduction. If something is really rusty, then the heat might break it up enough to loosen it. Personally, I don't like heating anything up till its cherry red as I don't really know what the material is made from and I am not in favor of stressing a material beyond its normal working limits. If its a bolt your just gonna throw away, then fine,,, but if its your crankcase on your engine...not me.

In any case, I had a drain plug stuck in a Kawasaki 12.5 hp engine last year. Stripped the thing round. A small pipe wrench, no heat, and tapping on the end while trying to twist it free did the job. Don't bang too hard!!!! Go slow!

Worst case scenario is that none of this works and you have to drill it out and use an easy-out to remove the rest. If you do have to drill it out, try to invert the engine if possible to get the chips out of there. Std drain plugs are pretty deep so only drilling half way in might allow the easy out to work without fear of getting chips in the engine.
If you do drill thru, flush the living crap out of it before restarting it.

Or, bring it to a small engine mechanic---they probably do this all the time. It will be worth the $50 in the end.

DiyDave
04-08-2007, 07:55 PM
There are reasons why I didn't recommend heat in my earlier post. Heating an oil pan with oil in in is not a good idea IMO, because you will scorch the oil in the bottom of pan. Scorched oil is about the texture of sand, and everybody needs a handful of sand in their oil pan. If you can't get the plug out, thread the hole you drilled in the oil plug, and put in a smaller plug or a bolt. Life is full of options, if it gives you lemons, find someone that life has given Vodka, and have a party! (Thanks Ron White)

Rowski
04-08-2007, 08:03 PM
Clean up the plug really well (brake clean) marking sure a fumes are gone! Place a nut over the drain plug hex. Weld the nut to the hex. Let it cool slightly and spin off with a wrench.

Derek

elshauno
04-16-2007, 10:38 PM
Thanks for all the replies I tried applying penetrating oil then heating it up and stopped due to concerns with the oil. That didn't work I'm going to go with welding a bolt it then impact wrenching it off