Thinking about breaking bolts, why they break etc.

[Danglerb]

I have a coolant bridge that runs between the heads on my car, with two hex head bolts on each side holding it down that are notorious for breaking. I sprayed them all good with Rost Off from Wurth on Thursday, and plan to start messing with them first thing Monday morning. This has me thinking about why bolts break.

Obviously the bolt has seized in some way.

Bolt is weakened, in this case contact with the coolant maybe.

Ratchets put side force on the bolt, not just a twist. What I am wondering is if some kind of T like a tap wrench with just twisting force might work best?

*** Note I am going to try all the tricks I know, whack it, work carefully and patiently, mostly I am curious about the side force issue with a plain ratchet.

 

[nissan_crawler]

I'll say the same thing I tell people that freak about using a ratchet with a tap. If you hold it right, there ISN'T side load.

 

[Junkman]

They break because the static grabbing forces are greater than the twisting forces of the tool that has been chosen to remove said bolt. If you choose a lesser quality tool, then the tool will break first, saving you the problem of the bolt breaking first. This was first explained to me by Professor Curly, and further clarified by Professor Mo.............

 

[Merkava_4]

Exposed to coolant, I'm thinking it might be worth the extra dollar to get stainless steel bolts to put back in.

 

[jay50]

Cast or AL heads. If you can get a little heat on them with a mini torch you might have a better chance of getting them out without breaking the bolt the resulting bad language (^%$^**) that follows when a bolt breaks in the head...LOL

 

[Thumper]

This sounds like a job for anti-seize !! ...That is AFTER you remove the old bolts.

 

[Charles (in GA)]

A not too powerful impact, such as a 3/8 drive turned down, will work better. The impact will tend to loosen the bolts/rust, something that just plain twisting with a wrench won't do.

Charles

 

[nissan_crawler]

A not too powerful impact, such as a 3/8 drive turned down, will work better. The impact will tend to loosen the bolts/rust, something that just plain twisting with a wrench won't do.

Charles

I love my mini 1/4" snap-on impact for that purpose. If I'm busy, I'll just spray the bolt down and ziptie the trigger on the impact and go do something else.

When I hear the whir, I go pull the ziptie off.

 

[russlaferrera]

IF the last person used some type of anti-seize you are OK. If not...give it your best shot. Because of the location the threads can be corroded, which you have no way of knowing. IMO it's a gamble so whatever happens...happens. Then deal with it.

I am not trying to piss ya off , but IMO this is all luck.

 

[eschoendorff]

I love my mini 1/4" snap-on impact for that purpose. If I'm busy, I'll just spray the bolt down and ziptie the trigger on the impact and go do something else.

When I hear the whir, I go pull the ziptie off.

That's great! I'll have to try that one of these days...

 

[rsanter]

differential metal corrosion
different materials in contact can cause corrosion to one of the materials depending on where the materials fall on the 'chart'

for example
if you build a bridge out of stainless steel and hold it together with iron bolts. the mass of stainless will rust out the iron bolts very quickly

if on the other hand you use iron or steel for the bridge and stainless for the bolts then the stainless bolts will try to rust out the rest of the bridge, but the difference in volume/mass will be such that the stainless will be at such a disadvantage that it will never effectivly happen

bob

 

[Stuey]

differential metal corrosion
different materials in contact can cause corrosion to one of the materials depending on where the materials fall on the 'chart'

for example
if you build a bridge out of stainless steel and hold it together with iron bolts. the mass of stainless will rust out the iron bolts very quickly

if on the other hand you use iron or steel for the bridge and stainless for the bolts then the stainless bolts will try to rust out the rest of the bridge, but the difference in volume/mass will be such that the stainless will be at such a disadvantage that it will never effectivly happen

bob

Yup! Now, where to find a detailed chart online...

 

[Merkava_4]

Danglerb

I was just thinking that if you're concerned about putting on a side load, that'd be a good excuse to get you one of those sliding T-handles.

 

[jimvannoy]

Put some anti seize on them

 

[MAD]

differential metal corrosion
different materials in contact can cause corrosion to one of the materials depending on where the materials fall on the 'chart'

for example
if you build a bridge out of stainless steel and hold it together with iron bolts. the mass of stainless will rust out the iron bolts very quickly

if on the other hand you use iron or steel for the bridge and stainless for the bolts then the stainless bolts will try to rust out the rest of the bridge, but the difference in volume/mass will be such that the stainless will be at such a disadvantage that it will never effectivly happen

bob

I experienced a good example of that type of galvanic corrosion a couple of weeks ago. I had damaged the air conditioning condenser on my wife's car while changing the drier/receiver and got another one from a junk yard. It seemed to be in good shape and did not appear to leak when I blew some air into it with my blow gun, so I installed it. I was able to pull a vacuum but when I charged the system I developed a major leak. There was a steel clip securing the aluminum tubing near one of the fittings and where the two dissimilar metals were touching the aluminum tubing had turned to dust.

 

[a390st]

It is best to be very careful getting steel bolts out of aluminium heads. If the fool who put them in went crazy tightening them, they can pull the threads coming out. Trust me, one of my techs pulled the threads out of a set of heads despite trying to be careful. The idiots who put them in had a reputation of not even owning a torque wrench in the whole shop and thinking a bolt was properly torqued when the big gorilla died from straining to tighten it.

 

[Fedwrench]

Think about the hundreds of thousands if not more, of cold to hot and hot to cold heat cycles the fasteners on your engine go through in their lifetime. When you add in other factors of dissimiliar metals, climate, lack of maintenance, lowest bidder suppliers, and put together by robots, it's amazing everything doesn't break.

 

[Vinko]

Speaking of bolts breaking, I was just reading in an industrial trade publication that the Chinese were caught maybe 5 years ago by the US Gov't -- maybe it was the Standards Office, for importing supposed "Grade 8" bolts that were really "Grade 5".

I was buying by the crate Grade 8 in America. Some guy here decided to save money, so went Chinese grade 8's (not Taiwanese, which in my opinion is sometimes okay), and we recently switched back to American-made Grade 8.

Even though more expensive, we found we had less problems and product liability and returns. So maybe the outlay upfront is worth it.

 

[jimvannoy]

Speaking of bolts breaking, I was just reading in an industrial trade publication that the Chinese were caught maybe 5 years ago by the US Gov't -- maybe it was the Standards Office, for importing supposed "Grade 8" bolts that were really "Grade 5".

I was buying by the crate Grade 8 in America. Some guy here decided to save money, so went Chinese grade 8's (not Taiwanese, which in my opinion is sometimes okay), and we recently switched back to American-made Grade 8.

Even though more expensive, we found we had less problems and product liability and returns. So maybe the outlay upfront is worth it.

If you are going to fasten critical parts together I would not even consider using an import bolt or nut.

 

[nissan_crawler]

If you are going to fasten any parts together I would not even consider using an import bolt or nut.

Fixed.

 

[Danglerb]

Its a Porsche bolt, put in last at the factory 25 years ago. Block and heads are Alusil, a high silicon content Aluminum. All the bolts related to the coolant system, this bridge, water pump housing etc. are notorious for breaking off due to coolant seeping under the seals over time and getting into the threads.

Antisieze goes on everything on these silly aluminum cars. I am actually going over 100% of the electrical connections cleaning and coating with Ox Gard (silicone grease with sacrificial zinc particles).

I agree, ratchet if you perfectly balance the force on the handle with an opposite force at the socket you get no bending, but it might be much easier to balance with a T.

Small impact on low setting sounds like a good idea.

OTOH fart around long enough and you should be able to break the bolt, drill it out, and put in a timesert in the same time.

*** note to self, take my thread chaser set with me.

 

[nissan_crawler]

OTOH fart around long enough and you should be able to break the bolt, drill it out, and put in a timesert in the same time.

Thank you for not saying heli-coil.

 

[foul_ball]

haven't worked with that Rost Off stuff before, but Kano Kroil with a little help from a propane torch has always worked well for loosening seized bolts, in my experience.

 

[Danglerb]

Kroil is good stuff, no idea exactly what Rost off is, but this shop has Wurth can everyplace and the Wurth guy stops in every couple weeks and tops up the stock including those drawers of bolts and orings etc.

What I have heard is best is 50/50 mix of acetone and ATF (power steering fluid specifically, but thats ATF right?).

Fuel lines are too close for me to use a torch.

 

[acmike]

Its a Porsche bolt, put in last at the factory 25 years ago. Block and heads are Alusil, a high silicon content Aluminum. All the bolts related to the coolant system, this bridge, water pump housing etc. are notorious for breaking off due to coolant seeping under the seals over time and getting into the threads.

Well, I found your problem. Porsches aren't supposed to have coolant, or water pumps.

 

[acmike]

Yup! Now, where to find a detailed chart online...

Simple enough..

http://www.engineersedge.com/galvanic_capatability.htm

You can read a bit about Galvanic Corrosion here:

http://en.wikipedia.org/wiki/Galvanic_corrosion

 

[MAD]

Well, I found your problem. Porsches aren't supposed to have coolant, or water pumps.

 

[Danglerb]

Well, I found your problem. Porsches aren't supposed to have coolant, or water pumps.

Gotta have a water pump, otherwise the windshield washer wouldn't work.



**** Yeah yeah, I know, I had a 914 once, and they use pressure from the spare tire to squirt washer fluid.

 

[foul_ball]

Kroil is good stuff, no idea exactly what Rost off is, but this shop has Wurth can everyplace and the Wurth guy stops in every couple weeks and tops up the stock including those drawers of bolts and orings etc.

What I have heard is best is 50/50 mix of acetone and ATF (power steering fluid specifically, but thats ATF right?).

Fuel lines are too close for me to use a torch.

Free is good!

 

[Merkava_4]

Speaking of bolts breaking, I was just reading in an industrial trade publication that the Chinese were caught maybe 5 years ago by the US Gov't -- maybe it was the Standards Office, for importing supposed "Grade 8" bolts that were really "Grade 5".

That's because the Chinese are the most fake *** sum ******* on the face of the Earth.

 

[Merkava_4]

Well, I found your problem. Porsches aren't supposed to have coolant, or water pumps.

That's funny!!!

 

[DiStOrTiOn]

I've never once willingly used a Chinese manufactured bolt. One of the guys I work with swears that if the box says Grade 8, they're Grade 8. Whenever I buy bolts, even if it's extra money and work, I get the made in USA stuff. Cheap hardware is like cheap paint, expensive in the end.

 

[ImportTuner]

I've never once willingly used a Chinese manufactured bolt. One of the guys I work with swears that if the box says Grade 8, they're Grade 8. Whenever I buy bolts, even if it's extra money and work, I get the made in USA stuff. Cheap hardware is like cheap paint, expensive in the end.

I agree with you, but it's getting harder and harder to find made in USA hardware. All the stuff at Home Depot, Lowes, OSH, and even ACE are either made in Mexico or overseas ...

 

[Mandres]

**** Yeah yeah, I know, I had a 914 once, and they use pressure from the spare tire to squirt washer fluid.

you're joking right? If not, awesome!

 

[MAD]

you're joking right? If not, awesome!

He is not joking. Old VWs used the same system too.

 

[Bob Paulin]

I've never once willingly used a Chinese manufactured bolt. One of the guys I work with swears that if the box says Grade 8, they're Grade 8. Whenever I buy bolts, even if it's extra money and work, I get the made in USA stuff. Cheap hardware is like cheap paint, expensive in the end.

There is no International agreement or obligation for the Chinese to guarantee that the markings on the bolt mean it meets or exceeds the standards associated with those markings in other parts of the world.


IOW - If the Chinese bolt makers choose to emboss the heads of lead bolts with six radial marks, they are free to do so.


Caveat Emptor!

 

[eschoendorff]

There is no International agreement or obligation for the Chinese to guarantee that the markings on the bolt mean it meets or exceeds the standards associated with those markings in other parts of the world.


IOW - If the Chinese bolt makers choose to emboss the heads of lead bolts with six radial marks, they are free to do so.


Caveat Emptor!

That just *****! Then again, only buy fasteners from trusted sources and you shouldn't have a problem....

 

[Vinko]

There is no International agreement or obligation for the Chinese to guarantee that the markings on the bolt mean it meets or exceeds the standards associated with those markings in other parts of the world.


IOW - If the Chinese bolt makers choose to emboss the heads of lead bolts with six radial marks, they are free to do so.


Caveat Emptor!

You may very well be right. I thought there was some obligation by the Chinese if they were importing into the US -- surely mislabeling a bolt, or "confusing" the consumer violates FTC laws, among others? At least that was my understanding from the article I read (referenced previously), but I can't now find it. Let me see if I can, just to get my own facts straight.

 

[Danglerb]

Someone selling the bogus bolts may get fried for doing it though depending on local laws.

 

[Bob Paulin]

That just *****! Then again, only buy fasteners from trusted sources and you shouldn't have a problem....

You can also ask your vendor for copies of the certification paperwork on the product he is selling you. You can keep the papers on file in the event that there is a lawsuit.

If he hesitates, then start getting suspicious.