Best way to remove tricky broken bolt?

[Fredrik1]

Hello!

Started dismantling the front suspension today. Most bolts cooperated, but three. And they must have been close to death anyway as I hardly applied any force at all, compared to other similar sized bolts seemingly stuck as bad. These are bad - first an important part: the upper wishbones, secondly, they broke below the surface. My go-to method for something like this has been to weld a nut on top of the remaining bolt, but this has mostly been bolts stuck in aluminium and not steel with the same melting temperature. Drill them out? I have hardly ever been lucky with that and would hate to damage the threads... Drill them out completely, make new threads and helicoil them back to the original thread and a bushing in the outer part? Do helical or similar make thread inserts for UNF? Other ideas? Some experienced views would be great here!

BR,

//Fredrik

[Robbiee]

I drilled mine out starting with a small drill and going up in size

[Gfhug]

Fredrik, with parts like that I’ve used heat then lots of plusgas, acf50 or similar. Not WD40. The heat tends to allow the lubricant to get deeper into the thread. Then when ready to try removing them use heat again, often the first thing is even to try tightening them before undoing them, going gently back and forth. All ways of gradually easing the threads to make the bolt or nut come undone.

If you break the bolt, can you drill out close enough to then clean out the thread before running a tap down it? I’ve had to do that a couple of times with care and patience. Similar to what Robbie suggests. Good luck.
Yes, helicoils are available in UNF, try looking at UK or US suppliers.

https://www.tracytools.com/helicoil-thr ... epair-kits
And they sell good quality drills and taps much better than you get in the average DIY store

Geoff

[Series1 Stu]

Penetrating oil followed by heat, followed by penetrating oil followed by heat. Repeat as necessary.

Drill through and use 'easy outs' starting as small as possible.

Persist and it will come out eventually.

Regards

[tim wood]

If I recall correctly the thread on this is open both ends. If so you could soak in something like atf.
If your really careful drill though, keeping dead central using small increments in drill sizes. Then maybe use an easy out ( although I’ve never had any success with these) or if you’re really lucky you will be left with just slivers of the remains that you can pick out.

[Fredrik1]

https://www.tracytools.com/helicoil-thr ... epair-kits
And they sell good quality drills and taps much better than you get in the average DIY store

Great! Have not heard about them previously! Thanks!

//F

[Fredrik1]

If I recall correctly the thread on this is open both ends. If so you could soak in something like atf.
If your really careful drill though, keeping dead central using small increments in drill sizes. Then maybe use an easy out ( although I’ve never had any success with these) or if you’re really lucky you will be left with just slivers of the remains that you can pick out.

Sorry, mine are closed-end... Made me forget other Christmas challenges at least!

[Fredrik1]

Penetrating oil followed by heat, followed by penetrating oil followed by heat. Repeat as necessary.

Drill through and use 'easy outs' starting as small as possible.

Persist and it will come out eventually.

These had been soaking in 5-56/WD-40 for a long time, but it did not make much of a difference. I'll mill the top of the brake flat and then start drilling...

[Gfhug]

Fredrik, don’t use WD40 it’s nowhere near as good as plusgas https://www.plusgas.co.uk/en-gb or ACF50 http://www.acf-50.co.uk/, proper penetrating fluids.
And you do need really good quality bits to drill out old bolts.

Geoff

[Series1 Stu]

These had been soaking in 5-56/WD-40 for a long time, but it did not make much of a difference. I'll mill the top of the brake flat and then start drilling...

It's the heat that's the important part. Add a few heat cycles to get the expansion/contraction going and to get penetrating oil in.

As has already been said, WD40 is not the best penetrating oil. I favour Plusgas.

Regards

[ysmalkie]

WD40 is useless. They should have made a significantly more tries than 40..

Get PB Blaster. Money well spent, even if you have to import it.
I have bought a gallon from the US and managed to dismantle couple of cars with it :-)

Tadek

[MdR]

Hi Fredrik, I've used this tool to remove a broken bolt.
This link is an exsample, there are more sizes and brands and shops, who sell them.

www.blackcomro.com/viewProduct?rlProdNum=BC350683


Succes, Marcel

[bitsobrits]

WD40 is useless. They should have made a significantly more tries than 40..

Tadek

WD40 was not designed to be a penetrating oil. "WD" stands for 'water displacement'. It's original intent was to be used as a surface treatment/cleaner. It's great for dissolving road tar on body panels, for example, and preventing water spots on polished metal. But it is a rather poor lubricant and penetrating oil because that is a misapplication of the product.

[angelw]

Fredrik Wrote:

Drill them out? I have hardly ever been lucky with that and would hate to damage the threads.

The trick is to start the drill in the centre of a surface that is irregular. If you have access to a Drill Press, set the Wishbone assembly up so that threaded hole is close to being concentric with the axis of the Drill Spindle and the axis of the bolt hole fairly vertical. You can get both aspects close enough by eye.

With the wishbone made immoveable under the spindle of the Drill, use a small diameter, solid carbide, ball nose end mill, circa 3 - 4mm diameter to create a start dimple in the centre of the broken bolt. Small Diameter, Solid Carbide end mills are relatively cheap and do a much better job than HSS.

Start with circa 4mm diameter, Left Hand Twist Drills to drill a hole in the bolt, the correct size for the appropriate Easy Out. The heat generated by the Drill will help and its Left Handedness will tend to unscrew the bolt. In some cases, the broken bolt will actually unscrew with the action of the Left Hand drill. If it doesn't, you will have a good true hole, very close to the centre of the broken bolt to apply an Easy Out, or other type of broken bolt extractor.

Regards

Bill

[Fredrik1]

As has already been said, WD40 is not the best penetrating oil. I favour Plusgas.

Ok, I need to get something like that! Thanks!

[Fredrik1]

Hi Fredrik, I've used this tool to remove a broken bolt.
This link is an exsample, there are more sizes and brands and shops, who sell them.
www.blackcomro.com/viewProduct?rlProdNum=BC350683

That's a new-to-me tool. Appreciated!

[Fredrik1]

Fredrik Wrote:

Drill them out? I have hardly ever been lucky with that and would hate to damage the threads.

The trick is to start the drill in the centre of a surface that is irregular. If you have access to a Drill Press, set the ...

Start with circa 4mm diameter, Left Hand Twist Drills to drill a hole in the bolt, the correct size for the...

I will start w a small end mill to get the surface flat. As you say a left twist drill is ideal - will get me a set!

Thanks!

//F

[autoalain]

Folks, thought I would post a little tip that has saved me many times, things like bleeders on calipers
and bolts that are stuck in something I use the impact gun rite BESIDE the offending thing, vibrate works,
honestly in the last 50 years EVERY bleeder I have tried does come out with snapping, vibrate and keep on putting pressure while the gun is going and after about 30 seconds it come loose. Mike

[Fredrik1]

Folks, thought I would post a little tip that has saved me many times, things like bleeders on calipers
and bolts that are stuck in something I use the impact gun rite BESIDE the offending thing, vibrate works,
honestly in the last 50 years EVERY bleeder I have tried does come out with snapping, vibrate and keep on putting pressure while the gun is going and after about 30 seconds it come loose. Mike

I've never heard about this. Sounds like something I want to try - do you have a picture? Do you keep it rotating? Or do you mean an air hammer?

BR,

//F

[autoalain]

I use an automotive air hammer, and trust me, it has saved me on lots of stuff. works like magic. Mike.