Seized Caliper Bracket Bolt !!!

[fritzintn]

Death to whomever torqued the front bolts on my M3.

Well in the process of changing pads/rotors I managed to get stuck. After removing the caliper, I went to remove the caliper mounting bracket from the hub. The lower bolt took quite a bit of coersing with the impact gun, some PB blaster, and the wratchet+jack trick. However after about 30 minutes with the impact gun and a gallon of PB blaster it wont budge!

Damnit.

Any suggestions on what to try next? I'm going to try a better impact gun in the morning and see how that goes. I'm just using the standard 90psi one that came with my 50gal air tool kit.

:mad :mad :mad :mad :mad

[Balthazarr]

You could try some heat on the bracket at that point, but I would just soak it with PB and let it sit overnight or for a few hrs at least.
Then tap cal bracket with hammer a few times and try ig again or breaker bar.

[3rd One]

yeah a stronger impact gun.....or what I did, get the socket on there and whack the ratchet with a heavy sledge hammer....broke it free for me.


no such thing as too much PB Blaster :devillook

[jgerry2002]

Use a hot torch, a propane torch might work, a butane torch would be even better. Get it nice and hot. I bet it would come off without too much of a fit.

The first time to remove those bolts is always a PITA. The other choice is to get it up on a lift and use lots of extensions for leverage from the bottom side.

Use some never seize/anti seize on them before you put it all back together.

-Justin

[JamesM3M5]

Use a hot torch, a propane torch might work, a butane torch would be even better. Get it nice and hot. I bet it would come off without too much of a fit.

The first time to remove those bolts is always a PITA. The other choice is to get it up on a lift and use lots of extensions for leverage from the bottom side.

Use some never seize/anti seize on them before you put it all back together.

-Justin
Yikes! Never use anti-seize on caliper bolts. They DO back out.

Heat is OK, but not too much heat. You can ruin the temper in the bolts.

Get a better impact gun. I had the same problem on my 95 M3. I bought an Ingersol Rand 2131A, blasted them out like they weren't even tight. The el-cheapo impact gun I had worked on wheel bolts (most of the time) and other fasteners, but once you get a stuck bolt, the cheapies don't do squat.

Use Loctite 262 on caliper bracket bolts. Loctite is a corrosion inhibtor and a thread locker. It will prevent seizing AND prevent loosening. Use 242 on the pin bolts (7mm allen).

[jgerry2002]

Yikes! Never use anti-seize on caliper bolts. They DO back out.

I change my brake pads before every track event, and I leave my stock pads in over the winter. I remove and retorque the hardware many times a season. I use antiseize on all the parts. Just a little, don't need to go crazy with it.

If they are properly torqued (I've seen too guys simply tighten things using a ratchet ignoring torque specs... loctite or not things will back out)., I doubt any of the bolts will back themselves out with anti-seize and the proper torque spec. I've never had any signs of that on any of the cars I've changed brakes on, even those cars I rarely change brakes on (my 2002 for instance).

If you do a brake job once every five years, then perhaps locktite would be a better choice. You might be able to make a case for the 16mm caliper carrier bolts. The guide pins? Torque spec is something like 25lbs/ft, anti-seize is no problem on these either.


Heat is OK, but not too much heat. You can ruin the temper in the bolts.

True, but the bolts are super cheap at your local dealer. If they are that tight to begin with check the condition of the threads.

As long as there is something on the threads, then either will work for the next time you have to disassemble.

As always your YMMV.

-Justin

[E36M3wantedinNY]

Yikes! Never use anti-seize on caliper bolts. They DO back out.

Heat is OK, but not too much heat. You can ruin the temper in the bolts.

Get a better impact gun. I had the same problem on my 95 M3. I bought an Ingersol Rand 2131A, blasted them out like they weren't even tight. The el-cheapo impact gun I had worked on wheel bolts (most of the time) and other fasteners, but once you get a stuck bolt, the cheapies don't do squat.

Use Loctite 262 on caliper bracket bolts. Loctite is a corrosion inhibtor and a thread locker. It will prevent seizing AND prevent loosening. Use 242 on the pin bolts (7mm allen).

funny, bavarian auto told me the exact opposite. they told me to use anti seize - even sold me a specific kind of anti seize they say is specifically made for those bolts. go figure.

[B.Watts]

funny, bavarian auto told me the exact opposite.

Consider the source. ;) They are a catalogue company.

Loctite seems far more appropriate than anti-seize for a bolt that is so important.

[KozanBMW]

Breaker bar will undo em. Worked for me very easily.

On a side note, I just got a impact gun with 300ft/lb. What is a good rated impact guns torque?

[Deadphan]

I had the same problem when I changed my rotors. I turned the wheels and then put a breaker bar will a really long piece of pipe on it. That worked like a charm.

[fritzintn]

I feel retarded.

I'm still stuck. I let the bolts swim in PB Blaster all night, then awoke this morning , went to Lowes and bought their biggest impact gun (550ft/lbs in reverse), and it did jack shit.

I eventually rounded off the bolt using a adjustable wrench and a breaker bar, so I ended up taking the bolt head off with a die grinder without messing anything up.

So now I have one bolt off, can't hear all that well in one ear, adn I'm just as stuck on the other side. What the shit.

[Sinned]

just sell your car...:D

[fritzintn]

just sell your car...:D

I seriously think its cursed. Might as well.

The car and the dire grinder have become too good of friends since I bought it (wheel lock woes last time :().

[B.Watts]

I eventually rounded off the bolt using a adjustable wrench and a breaker bar

Mistake #1. Never use an adjustable wrench when dealing with stuck bolts or high torque situations. Get a high quality socket, a good breaker bar, and a rubber hammer or a long piece of tubing for extra force.


so I ended up taking the bolt head off with a die grinder without messing anything up.

Is the threaded portion of the bolt still stuck?

[fritzintn]

Mistake #1. Never use an adjustable wrench when dealing with stuck bolts or high torque situations. Get a high quality socket, a good breaker bar, and a rubber hammer or a long piece of tubing for extra force.



Yeah i know. This was more of an act of desperation.

The socket + breaker bar wouldn't clear the fender. Even when I placed the car on jackstands high enough to get under the car with a breaker bar, the socket would twist and fall off.



Is the threaded portion of the bolt still stuck?

Nope.

I unthreaded it easily by hand. The same thing happened with my wheel locks... odd.

EDIT - Somewhere along this ordeal I gave it the wrath of my propane torch (I like to call him Trogdor), which didnt seem to do much but singe the paint on the konis.

[Balthazarr]

What's odd about it? You cut the head off and it was no longer tight bc bolts stretch for fastening.
That is what they are supposed to do.

[JamesM3M5]

funny, bavarian auto told me the exact opposite. they told me to use anti seize - even sold me a specific kind of anti seize they say is specifically made for those bolts. go figure.
Yeah, my brother did this as well. One of the bolts backed out and the caliper swung into the wheel. Luckily it didn't blow a hole in the wheel, it just scraped along the inside.

BMW uses a threadlocker on them. Some new brake caliper bolts even come with dry threadlocker already applied to the threads. No matter what anyone else thinks, I still think that anti-seize is bad idea for caliper bolts.


I'm still stuck. I let the bolts swim in PB Blaster all night, then awoke this morning , went to Lowes and bought their biggest impact gun (550ft/lbs in reverse), and it did jack shit.

The good impact guns from Home Depot and Lowes still stink. Use an Ingersol Rand or Snap On. Expensive, but isn't it worth it to save you all this trouble just this one time? Do not use the thin yellow self coiling hoses, they choke off too much flow. Use hi-flow 3/8" connectors instead of the standard choker 1/4" quick connects.

[E36M3wantedinNY]

Yeah, my brother did this as well. One of the bolts backed out and the caliper swung into the wheel. Luckily it didn't blow a hole in the wheel, it just scraped along the inside.

BMW uses a threadlocker on them. Some new brake caliper bolts even come with dry threadlocker already applied to the threads. No matter what anyone else thinks, I still think that anti-seize is bad idea for caliper bolts.



The good impact guns from Home Depot and Lowes still stink. Use an Ingersol Rand or Snap On. Expensive, but isn't it worth it to save you all this trouble just this one time? Do not use the thin yellow self coiling hoses, they choke off too much flow. Use hi-flow 3/8" connectors instead of the standard choker 1/4" quick connects.


is it possible there were some other "bolt" that they may have been telling me to use the anti seize on? I bought the "caliper bushing kit"
here's the description:


"Simple upgrade gives BMW brakes a better feel and more even pad wear. The stock caliper on most BMWs uses a rubber guide pin bushing that allows the caliper to “twist” when you brake. This upgrade – a combination of precision guide pin and machined brass bushing – eliminates “twist” and allows the caliper to squeeze more evenly. You get a better feel and longer pad wear. Set of four; one set required per axle.

We recommend also purchasing Stalube - Synthetic Brake Caliper Grease Part # 3301, and Anti Seize Compound Part # 2012 "

is this the bolt in question that i should use locktite on? I was under the impression these are the bolts the caliper itself slides on when the piston is compressed, and that you guys are talking about using locktite on the bolts that hold the caliper to the mounting point, or the carrier?

[fritzintn]

Well I ended up just taking a cut-off wheel to the bolt heads and a die grinder to what was left behind. I managed to get all the bolts off and keep any scoring to the bracket at a minimum.

Threw some high heat paint on the small scratches I made to the bracket to keep rust away and went about removing the rotors.

It turns out the previous owner put the front rotors on backwards so they 'scooped' the air. This apparently warped them after a few track days and autocrosses, yet I had tons of 'meat' left on the pads still.

Oh well, all is well now.

[mgambini]

I've always used a good quality 6 point socket, a 24" breaker bar, penetrating oil, and couple of taps with a hammer to get these off. I do have a Snap-on impact wrench but I have always found it easier to get in there with the breaker bar.
MikeG

[B.Watts]

is this the bolt in question that i should use locktite on? I was under the impression these are the bolts the caliper itself slides on when the piston is compressed, and that you guys are talking about using locktite on the bolts that hold the caliper to the mounting point, or the carrier?

Totally different bolt. Use locktite on the bolts that hold the caliper to the bracket. The guide bolts you are referring to should be greased, but not the threads...just the shank portion that the caliper slides on.

[JamesM3M5]

I use Anti-seize on the pad backing at every point it touches the caliper. This helps prevent squeal. The slider bolt should be greased with silicone based grease on the smooth portion. Other greases will harm the rubber. You can use medium strength loctite (242) on those bolts, but it is not necessary.

[funkmasta]

for future reference, if you turn the wheel all the way (full right for DS, and full left for PS) you can get a breaker bar on there pretty easily...

[B.Watts]

The slider bolt should be greased with silicone based grease on the smooth portion. Other greases will harm the rubber.

No worries about the rubber...he's got the brass bushings. ;)

[GasGasRider]

A good impact gun will do at least 450 ft lbs. right [on] and 600 left [off] however I would not recomend using one on such small bolts, too high a chance of just breaking it.
A high quality penetrating oil, heat [get the bolt not much less than red hot and let it cool al the way down] and small hammer induced vibration will be your best friends.
I work on large cranes for a living and we have found Kroil ' the oil that creeps' to be by far the best out there...if you can't find it they probably have a web site. We antisieze bolts at least as important as your brakes daily, this I guess is just personal preference.
Cannot emphasize enough that if you have ANY doubt on the integrity of any brake or suspension related fastener just replace it with the proper quality / grade part...it's worth every $.

[aespen]

how much air pressure does your compressor generate? You need more than 90 psi, in my experience, to loosen really stuck fasteners.

[gilesmortimer]

I feel retarded.

I'm still stuck. I let the bolts swim in PB Blaster all night, then awoke this morning , went to Lowes and bought their biggest impact gun (550ft/lbs in reverse), and it did jack shit.

I eventually rounded off the bolt using a adjustable wrench and a breaker bar, so I ended up taking the bolt head off with a die grinder without messing anything up.

So now I have one bolt off, can't hear all that well in one ear, adn I'm just as stuck on the other side. What the shit.

If you use an adjustable wrench what do you expect? adjustable wrenches are for cowboys!

[mgraney]

Yeah i know. This was more of an act of desperation.

The socket + breaker bar wouldn't clear the fender. Even when I placed the car on jackstands high enough to get under the car with a breaker bar, the socket would twist and fall off.



I just did this yesterday on my car. If you turn the steering wheel you can get a better angle. Also, use a breaker bar that has a swiveling tip. I was able to angle the breaker bar so that it cleared my fender, while the socket was still perfectly on the bolt.

Also, it sounds liek your socket may have been the wrong size. Maybe a standard instead of metric?

[fritzintn]

I just did this yesterday on my car. If you turn the steering wheel you can get a better angle. Also, use a breaker bar that has a swiveling tip. I was able to angle the breaker bar so that it cleared my fender, while the socket was still perfectly on the bolt.

Also, it sounds liek your socket may have been the wrong size. Maybe a standard instead of metric?

Nope, I went through about 3 properly sized sockets of various size/style with no luck. I even managed to get a breaker bar in there as well... still no luck. I finally just spent a few (er lots) minutes with a die grinder and took the head of the bolts off, then replaced them with new ones from the dealer.

Apparently the previous owner put the rotors on backwards so they were retaining heat. After a whole lot of track miles I guess I nearly welded the bolts on. I'm guessing this was the reason I had problems with my wheel locks earlier as well.

Oh well, as is well now. It just further concreted my belief that I should do all the work I possibly can myself.

[golfiiicl]

So it tried everything listed here, and all I accomplished was rounding off the nut (Snap on gun and sockets), then I took a grinder to the heads (turn the wheels away to reach easily) and I got everything off in 10 minutes now all I have to do is replace the bracket which is fine since I am replacing the calipers too.

I feel stupid for spending hours trying everything else.