Evil seized caliper bracket bolt from hell

What's up guys representing from north of norway where subies are in their right element defeating winter every day with snow most of the year here.

 

Anyway guys as much as I love my 2011 subaru legacy premium estate I'm kinda gettin my balls kicked a lot by this one stupid son of a **tch caliper bracket bolt that seems to just be _beyond_ seized.

 

To begin with I just clanked the wrench with a hammer yak-yak-yak like you'd normally do to loosen these fellas up a little before going all the way. After doing that for some time and realizing that hey this just isn't going anywhere I started the next step with another wrench to get leverage and so on. Before I knew it the bolt was stripped.

 

After that I've done countless rounds of WD40, hit it with the torch for what seems like hours, I've used a special spray to cool it down to -40 celsius, I've hit it with the angle grinder to square it up a lil' bit but guys nothing is happening!

 

The bolt head is now abused and deformed beyond recognition. Cant get a grip with anything now.

 

So guys what do you think?

 

What should be my next move? I don't wanna go crying to the mechanic like a little wuzz. So guys please help me out here I'd be so greatful.

 

Peace out from Norway

well - you could grind flats on it to try with a wrench again. or just grind the head off, then when you have the caliper off you will have access to the threaded section - use a penetrant, then try backing it out...

 

If the head were still intact, I would recommend an impact as they are much better at getting a stuck bolt out than lots of torque (which tends to round off the head, as you found out, unfortunately)

Since you have a rounded head try a pipe wrench, a big one, with really sharp teeth. Or an extractor or some sort.

 

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WD40 is not nearly as good as a true penetrating oil. If you can find a product called Kano Kroil, it works really well on rusted fasteners in the exhaust system and suspension. Rust seems to just dissolve. A 50/50 mixture of auto trans fluid and acetone works better than many commercial penetrating oils.

 

The trick is to apply the penetrating oil several hours before you do the job, even overnight. Tap the fastener with a light hammer or mallet to encourage the oil to penetrate. A repeat treatment sometimes helps.

 

You can try a bolt extractor tool. If that won't work, you have to resort to grinding the bolt head down and chiseling it off.

Bolts like that I'd soak in penatrant and leave sit for a day while hitting every so often with more penatrant. Then try again. Sometimes try tightening a little to break it loose then back it back out. If that fails, center punch the bolt, drill it and try an easy out. If that fails, use a drill bit just smaller than the threads and drill the whole bolt out and run the correct tap through to clean/re tap the threads.

Invest in one of these kits. Saved my ass removing the down pipe bolts from the turbo. Just smack it on with a hammer and use a breaker bar/impact. After some grunting and cussing...they broke loose.

Those work very well, Irwin makes several sets too. https://www.amazon.com/IRWIN-HANSON-BOLT-GRIP-Extractor-394001/dp/B0000CCXVZ

^^ I have the Irwin set and it works great.

Thanks for the link. I'll have to pick up a set.

 

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bringing it back from the dead.

 

what if that extractor set doesn't get a good enough bite on the head to apply the torque? my set isn't the Irwin set, but rather an older Snap-On set and I think the teeth are just not digging deep enough. should I just go to lowes and buy a replacement Irwin set and test my luck, or is there another method you would recommend?

 

FTR, i'm talking about a stuck headbolt and the head is almost completely rounded. I tried my extractor to no avail, I can get it to catch, but as soon as I apply any torque, it comes off. I've coupled that with an air hammer and that was pointless. I highly doubt a countersink will work just because of the shear amount of torque it's under. drilling it out will be my last resort as I don't want metal shavings in the head.

@JazzAvi8r your final bastion when the bolt is completely rounded is the following no turning back method. If this doesn't work you are cutting the bolt head off, drilling out the bolt and using a big cert kit (it's been tested to be the strongest).

 

Things you will need:

-An impact driver, air powered is better

-A 6 sided impact socket 1 size smaller 17mm bolt -> 16mm ratchet

-A hammer

-An oxyacetylene torch

 

Get all of your tools handy an near by because you don't want to waste time trying to grab one. Also do one last prep of the penetrating oil before hand.

1. Use the torch with a blue flame to heat until the bolt is glowing red almost orange. be careful not to point the flame past your bolt head to anything important.

2. Grab that one-dress-size-too-small socket and quickly hammer it on to German specifications (gutentight)

3. Use the air ratchet, make sure it's on reverse, and pray it takes the bolt out without damaging any threads. If it does damage threads say hello to a big cert kit.

 

You can of course try your extractors one more time after allowing a proper soak of the penetrating oil or the other tricks mentioned above. If you don't have all of the above tools you will want to find a local DIY garage or a friend with a well stocked garage. If you can't get a hold of a torch ask around your friend group to find a welder. He (or she) will be able to get a hold of a torch and help you use it.

 

These are the two bigsert kits you can use to fix the threads on Subaru brake calipers:

M10x1.5 Bigcert Kit

M12x1.5 Bigcert Kit

Also here is the youtube video where the guy tests the pull out strength of all the common thread repair methods:

kinda long but a fun interesting watch if you're into geeky engineering stuff

I have all of that. I just didn't want to apply significant amount of heat to a solid steel bolt when the surrounding head is all aluminum. i'm not so much concerned about the block, but I need to save the head. if there was enough space, I would just take an angle grinder to the head of the bolt and remove it that way. once I slide the head off the bolt, then I can deal with the problem of removing the stud later. I just need to get the head off so I can take it to a machine shop (2011 STi for what it's worth).

 

instead of using the Oxyacetalene torch, I could use a propane torch (much cooler) and just kinda warm it up before I jam an extractor on it. does that sound feasible?

You can try a propane torch but like you said it's much cooler. What we are going for with the extreme heat is to weaken the rust/contact weld that has occurred between the bold and the hole.

 

Sending heat into the the bolt and therefore the aluminum will allow each to expand. Aluminum alloys have a coefficient of linear expansion between 21 and 24. Most steel alloys are in the 9-11 range. This means for each degree you heat the aluminum it will expand twice as much as the steel bolt. If there is any friction fit or interference fit from the oxidation the expansion can be enough to reduce the force needed to take the bolt out.

 

The other thing we are accomplishing with heat is weakening the steel to the point that hammer on the socket shapes the steel to have new flat faces to pry against. Let me get a picture uploaded here real quick.

 

Picture of what the nut looked like after the war was over.

 

 

You are right to be worried about heating the aluminum to much. Depending on the alloy Aluminum can melt between 865-1240 F. Most steel alloys do not begin glowing until they reach 500-900 degrees. We can safely assume the steel alloy used for brake calipers is selected to have a higher tolerance for heat. My previous experience pulling this trick has only been steel on steel but if we stick to the lower levels of glowing red we should be fine.

 

 

Steel glowing chart

::C ----- ::F ---- Color

 

400 -- 752 -- Red heat, visible in the dark

474 -- 885 -- Red heat, visible in the twilight

525 -- 975 -- Red heat, visible in the daylight

581 -- 1077 - Red heat, visible in the sunlight

700 -- 1292 - Dark red

800 -- 1472 - Dull cherry-red

900 -- 1652 - Cherry-red

1000 - 1832 - Bright cherry-red

1100 - 2012 - Orange-red

Apparently there is also this fun trick. Note he uses a propane torch and candle wax.

 

 

No sure if you want to go that far. Also the guy sounds like John C. Reilly from Kong Skull Island.

You could drill the head off of the bolt so you can separate the head from the block, and at that point, you should be able to get a good grasp on it with vise grips or weld a nut on it or something like that. Drilling might be tricky now that it's rounded, but if you kiss the top with the side of a grinder (or a grinding stone in a Dremel), that may be enough to get you started. That and maybe a slot in the head with a Dremel cut-off wheel should be enough to at least get the bolt head off in chunks, and you can clean the edges up with a file or something prior to removing the head.

 

Also, you have to get steel pretty hot to soften it up, and the aluminum head will suck heat out pretty quickly. Not sure I'd apply heat to do anything more than expansion things slightly or loosen up corrosion.

Once the head is removed there should be very little tension on the bolt at all. I would go this route, the bolt is done now anyway.

I got it off. Turns out, my snap on set is 20 years old and just worn out. Bought the irwin set from Lowe's and the botch just pooped right off

Congrats! Bet that felt good

 

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Congrats! Bet that felt good

 

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A release after a long time spent with tension always feels good.

that's what she said?!?

 

yeah, it felt good. I was really dreading having to drill it out. I don't often let cars punk me; but this one almost got me.

 

if anyone wants to follow my build, it's here:

http://legacygt.com/forums/showthread.php/sti-rebuild-268211.html?p=5760508#post5760508

This is what I use to remove brake parts bolts. It works every time...

 

http://i.ebayimg.com/images/i/151768371435-0-1/s-l1000.jpg