Removing a hex bolt that is in tight

[GSCJR]

These are the times when good quality tools pay for themselves.

 

[CleanSump]

Not to be argumentative. My '92 300D had red stuff on the threads, not blue. I remember cleaning peices out of the hole threads with a pick.
I live by blue with motorcycles. Red I only use when called for in a manual because it's, like, not supposed to be easy to remove.

 

[SubLGT]

....My concern is rounding the stupid hex bolt out. Then I’m really screwed.

Try a RBRT hex driver from Mac or Proto.

1/2" Drive R.B.R.T. Hex Driver 12mm

Innovative and exclusive anti-slip dual directional driver .Bi-Directional - works for both loosening and tightening fasteners .Prevents rounding of new fasteners .Effective at removing compromised fasteners .S2 tool steel bits are precision machined

www.mactools.com

 

[ms21043]

Looking closer at the pictures, the bolt is a shoulder bolt. Shoulder bolts have a short effective length. Bolts rely on stretch and spring tension to keep them in place. Regular bolts effective area starts from under the bolt head, shoulder bolts start from the shoulder, so not much stretch. When removing a regular bolt you are overcoming head bearing surface area friction + thread friction. On a shoulder bolt it's more the surface bearing area friction you are trying to overcome. The lack of effective area on this bolt is why there's thread locker on it.

Also, thought it was an external hex, but it's an internal. Yeah, try a longer 1/2" drive breaker bar. Make sure the hex is fully engaged and squared up, if possible, support the drive end of the breaker bar. If your socket is 3/8" drive, you'll need a 1/2" drive one to connect directly to the breaker bar, don't try adapting a 3/8 drive to a 1/2 drive breaker bar. Give the bar a quick hard shove to loosen, if you're lucky it should pop loose with a bang. Once this happens, it should be loose enough to easily remove without much effort.

 

[spasm3]

Last idea i have besides heat, is to insert the hex socket by itself, then give it some taps straight on with a ball peen hammer, or whatever you have.

 

[GON]

I have a right angle air impact but no 3/8 impact hex. Might need to just buy a cheapie to ruin.

I broke a brand-new HF 3/8 impact hex a few years ago working on a Mercedes. Might want to look at a COA of buying a Snap-On or equivalent 3/8 impact hex.

 

[JHZR2]

These are the times when good quality tools pay for themselves.

That’s all I have. All US made quality tools.

I broke a brand-new HF 3/8 impact hex a few years ago working on a Mercedes. Might want to look at a COA of buying a Snap-On or equivalent 3/8 impact hex.

If I can find one tomorrow. Really want to get this done tomorrow when I have time.

Last idea i have besides heat, is to insert the hex socket by itself, then give it some taps straight on with a ball peen hammer, or whatever you have.

Not enough space between the radiator and bolt. Heat is easier - driving a bit then heating the bolt.

Looking closer at the pictures, the bolt is a shoulder bolt. Shoulder bolts have a short effective length. Bolts rely on stretch and spring tension to keep them in place. Regular bolts effective area starts from under the bolt head, shoulder bolts start from the shoulder, so not much stretch. When removing a regular bolt you are overcoming head bearing surface area friction + thread friction. On a shoulder bolt it's more the surface bearing area friction you are trying to overcome. The lack of effective area on this bolt is why there's thread locker on it.

Also, thought it was an external hex, but it's an internal. Yeah, try a longer 1/2" drive breaker bar. Make sure the hex is fully engaged and squared up, if possible, support the drive end of the breaker bar. If your socket is 3/8" drive, you'll need a 1/2" drive one to connect directly to the breaker bar, don't try adapting a 3/8 drive to a 1/2 drive breaker bar. Give the bar a quick hard shove to loosen, if you're lucky it should pop loose with a bang. Once this happens, it should be loose enough to easily remove without much effort.

Ideally this is all it will take. A good blow on a longer 1/2” drive breaker bar.

 

[JHZR2]

Try a RBRT hex driver from Mac or Proto.

1/2" Drive R.B.R.T. Hex Driver 12mm

Innovative and exclusive anti-slip dual directional driver .Bi-Directional - works for both loosening and tightening fasteners .Prevents rounding of new fasteners .Effective at removing compromised fasteners .S2 tool steel bits are precision machined

www.mactools.com

I have a set of the proto ones.

Sigh…

Fortunately I haven’t rounded it yet!!

 

[Number_35]

Not enough space between the radiator and bolt. Heat is easier - driving a bit then heating the bolt.

Would it be worth it to remove the rad?

 

[JHZR2]

Would it be worth it to remove the rad?

If I need to, to get frontal access, sure, the radiator and condenser could come out.

I sure hope it doesn’t get to that. I was mildly surprised that the bolt didn’t budge with basic tools. I just want to avoid issues that would cause me to have to take that sort of significant action if I can be smart about it!

 

[97K15004WD]

Why are you opposed to heating the bolt to loosen/break the bond on the Locktite/threadlocker?

 

[zray1]

After you’ve verified it’s not a LH thread, this would be my next step:

CRC Freeze-Off

It works in seconds : minutes not hours or days. I’ve used it on many applications, from bolts & nuts to stuck on disc brake rotors, which had resisted all types of impacts from a mini-sledge.


You have to use a liberal amount of it, up to a 1/2 can if needed. . Ventilate the work area as the fumes are toxic as well as extremely flammable. spray directly on the bolt head and flange as well as the surrounding area. Use your removal wrench immediately before the bolt has a chance to warm up. The Freeze-Off will be effective against all types of thread sealer, including loctite red.


The key is to use A LOT of it, otherwise it won’t help.

Z

 

[JHZR2]

Why are you opposed to heating the bolt to loosen/break the bond on the Locktite/threadlocker?

I’m not. I’m interested in doing it the right way. This bolt goes into the block. A giant thermal mass. It’s a dissimilar metal combo so different expansion rates.

And I’m working in a tiny space between the radiator and the front of the engine block.

And I’m not sure why I even need heat since the product used is not one that needs to be melted, nor is corrosion of fasteners on any other bolt on the front of the engine an issue.

I get it that heat helps. In theory this should have come apart. Since it’s a female hex and rounding it out can be a recipe for disaster, I’m just trying to get it all right before doing anything.

 

[Quantico]

Is there an issue with using an impact to remove a loctited bolt? For example with residues in the female threads?


I’m not sure how that would work. The tensioner looks like this:

View attachment 120581

If I hit the bolt with heat, it would expand faster than the block that it’s threaded into. Wouldn’t that make it ultimately harder to remove and more chance to damage the threads? I would think at minimum if I use heat, I need to get the engine up to temperature so there isn’t a huge disparity.

The heat loosens the locktite bond.. and heat and cold cycles break loose corrosion on the threads.


I would use my oxi torch for heat. And an impact 3/8 inch 6 point socket and 3/8 inch impact. If all goes to hell you can use a carbide burr to remove the hex head. Kroil in the threads is a plus. The more the better.

 

[Quantico]

Just realized its not an external hex. But the good impact socket n impact is still the answer.

 

[Quantico]

I would highly recommend buying a snap on quality hardened socket.. it will be stronger and transmit torque better and will fit tighter.

 

[IndyIan]

After you’ve verified it’s not a LH thread, this would be my next step:

CRC Freeze-Off

It works in seconds : minutes not hours or days. I’ve used it on many applications, from bolts & nuts to stuck on disc brake rotors, which had resisted all types of impacts from a mini-sledge.


You have to use a liberal amount of it, up to a 1/2 can if needed. . Ventilate the work area as the fumes are toxic as well as extremely flammable. spray directly on the bolt head and flange as well as the surrounding area. Use your removal wrench immediately before the bolt has a chance to warm up. The Freeze-Off will be effective against all types of thread sealer, including loctite red.


The key is to use A LOT of it, otherwise it won’t help.

View attachment 120623

Z

I'll have to get a can of that stuff, as I don't have anything hotter than a propane torch, which I have found is mostly useless... Maybe for loctite I guess but seems to do nothing for rust.

 

[JHZR2]

I appreciate all the comments.

Sometimes you just need a longer ratchet.

I wanted to do it right, and it didn’t HAVE to be done today, but I wanted to try…. HF had a 1/2” impact hex kit and I decided to try it. Could always return it to get better tools if the bolt wouldn’t budge.

I had to know. It budged. All good.

Now this afternoon/tonight I can finish this phase of the job.

 

[chrlsful]

I have a new Mercedes tensioner, it’s the same as the one on there. They are installed with some sort of thread locking sealant.
Thanks!

yeah, right -
called Ionic Interaction or sompin - steel's interface & corrode w/alu. Happens in the other industries too.
1st is penetrating fluid'n wait then more, wait'n try; wrk ur way upto the fire wrench as above (if needed). Then onto mig-a-bolt head on (steel to steel) the end. Once U get even a slight turn go back, then forth a lill past last point, and back, then past furthest point, till at least 1 full rev. More p. fluid in there.
We learn this w/exh head bolts, etc. There's many 'of problem' & just something to put up with when doin alota wrenchin. There's a tendency to avoid use of 'easy out' as those just bugger the hole, one needs to pull alota other components out to get access. But that (and often a resultant helicoil can also transpire). Frustration is dealt w/by getting on another job B4 returning. As an ol timer, hand cramps are worked out too, B4 a return. HTH, Good Luck

 

[GON]

I appreciate all the comments.

Sometimes you just need a longer ratchet.

View attachment 120625

I wanted to do it right, and it didn’t HAVE to be done today, but I wanted to try…. HF had a 1/2” impact hex kit and I decided to try it. Could always return it to get better tools if the bolt wouldn’t budge.

I had to know. It budged. All good.

Now this afternoon/tonight I can finish this phase of the job.

JHZR2,

Congrats on mission accomplishment! Did the removed bolt have Loctite on the threads?