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Discussion Starter #1
Curious, does anyone know the size of the bolts that hold on the front caliper brackets? I'm asking because I plan to remove the rotors and replace, but when I went to tackle it last time I didn't have a socket big enough and don't feel like running out to get the size....
 

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M14, p/n 5093355AB
Thats the bolt for the caliper to hold it to the bracket.

I think the OP is talking about the actual bracket that wraps around the rotor, the pads mount in it and the caliper bolts to it.

If I remember correctly it was a 19mm bolt head, but its been a while, I have sockets this size so it didn't stand out to me, it might be even larger than that.

19mm is the same size for the lug nuts, so you could always pull out the lug wrench that is in the back with the tire jack and use it to remove the bolts, at least check to see if it fits.
 

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Ahhhh, OK, the link comes up to a diagram that seems to show the bolts for the caliper to the adapter.

So, this may or may NOT work, but the lug wrench that is in the back with the scissors jack should fit a 19mm bolt head. Of course its a compact wrench, might NOT be enough leverage, but worth a shot if you're trying to do this on the cheap, at least you definitely confirm what size socket you'll need to get.
 

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I checked it, head size is 21mm. not 19. M14 bolt corresponds to 21mm head normally. Torque is 129 Nm (95 ft lb)
 

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21mm socket with 95 ft-lbs (actually greater, maybe a lot more, for a bolt that has been torqued down that long)?

nserafini you might want to consider picking up a 2' breaker bar with the socket. If I remember correctly, I had to break those bolts free with my 2' breaker bar, the 8" socket wrench wasn't enough leverage for those big bolts.
 

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Discussion Starter #8
21mm socket with 95 ft-lbs (actually greater, maybe a lot more, for a bolt that has been torqued down that long)?

nserafini you might want to consider picking up a 2' breaker bar with the socket. If I remember correctly, I had to break those bolts free with my 2' breaker bar, the 8" socket wrench wasn't enough leverage for those big bolts.
Thanks kids. I've been putting it off because the last two times I went to remove a wheel, I've rounded the acorn nut ( I have a 4-way wrench and even though the size should be exact for the nut, it seems that my gorilla hands can round it ).... Perhaps if the weather is nice this weekend I'll go pickup new nuts, a 21mm, breaker bar and plan to curse the gods trying to get them off.. Or I'll take it to a shop and see what they will charge to do the work :)
 

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After you get the caliper off there is a rubber o ring that holds that rotor on.
It is on the hub or unit bearing.
That is if it is still the stock rotor.
Most people leave it off after they put new rotors on.
I think it is there more for assy. at the factory.
Make sure you torque the caliper bracket back on to factory specs! It may see excessive but I have seen them come loose before.
 

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Thanks kids. I've been putting it off because the last two times I went to remove a wheel, I've rounded the acorn nut ( I have a 4-way wrench and even though the size should be exact for the nut, it seems that my gorilla hands can round it ).... Perhaps if the weather is nice this weekend I'll go pickup new nuts, a 21mm, breaker bar and plan to curse the gods trying to get them off.. Or I'll take it to a shop and see what they will charge to do the work :)
? You rounded it yourself while tightening it? OR, you've rounded the nut trying to loosen them? Often shops overtorque the lug nuts because they use air impact wrenches to tighten the lug nuts, but idea, and it ruins the lug nuts and studs, if NOT causes them to break and pop off while driving.

If you're rounding the lug nuts, something is wrong, either they were overtorqued by a previous owner/shop, OR your wrench/socket does NOT fit properly, OR you're overtorquing the lug nuts yourself.

The socket size for the OEM lug nuts is 19mm or 3/4", both are the same size, and will fit properly and NOT round off the lug nuts.

With aluminum wheels it is critical to have the correct clamping surface (tapered, rounded, flat) make sure the replacement lugs have the correct surface, take an old one with you to the auto store to compare with the new set you're looking at buying.
After you get the caliper off there is a rubber o ring that holds that rotor on.
It is on the hub or unit bearing.
That is if it is still the stock rotor.
Most people leave it off after they put new rotors on.
I think it is there more for assy. at the factory.
That is exactly what it is there for, to hold the rotor flush against the hub while it is moving down the assembly line to the next station where the caliper gets installed.
No need to keep it, but some people do because if you remove the caliper to change pads, the rotor will tilt and NOT hold flush on the hub. You can accomplish the same effect by just threading one of the lug nuts down to the rotor to hold it in place.
Make sure you torque the caliper bracket back on to factory specs! It may see excessive but I have seen them come loose before.
Use a little blue loctite on it, not only to prevent it from coming loose, but to seal out road salt and moisture that might cause corrosion and seize those bolts for the next time you need to pull them.
 

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Discussion Starter #11
? You rounded it yourself while tightening it? OR, you've rounded the nut trying to loosen them? Often shops overtorque the lug nuts because they use air impact wrenches to tighten the lug nuts, but idea, and it ruins the lug nuts and studs, if NOT causes them to break and pop off while driving.

If you're rounding the lug nuts, something is wrong, either they were overtorqued by a previous owner/shop, OR your wrench/socket does NOT fit properly, OR you're overtorquing the lug nuts yourself.

The socket size for the OEM lug nuts is 19mm or 3/4", both are the same size, and will fit properly and NOT round off the lug nuts.

With aluminum wheels it is critical to have the correct clamping surface (tapered, rounded, flat) make sure the replacement lugs have the correct surface, take an old one with you to the auto store to compare with the new set you're looking at buying.
So I finally got around to doing it this Sunday. It wasn't an adventure, but it was tough. First, I found that my 4 way wrench is the culprit for my rounded lugs. It fit on the lug, but there is just a little play.. Just enough to round really tight lugs. First I went and picked up a set of Gorilla locks and lugs, fought off the old one that were rounded. No problems with the actual spare tire iron.

Then I did the rotors. The 21mm bolts were tight. I ended up using the breaker bar and a few love taps from a hammer, but they came off. The real problem was the rotors being rusted on. My trusty adjustment device ( 10lb sledge hammer ) was required on both sides. Of course mindful of not hitting a stud, the axle or the body.

Took about an hour on the first side, just sort of getting the feel. The passenger side took 30 minutes from jack up to jack down. Thanks all!
 

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Yea, my grandfather gave me a 4-way lug wrench, it still sits on the shelf and I never use it.

I use a breaker bar with a deep well socket the proper size for the lug nuts, then torque wrench set to 100 ft-lbs to tighten them in a star pattern with the same deep well socket. I've never rounded a lug nut, but I did ruin a set of studs on a mini-van years ago, using excessive oil/anti-seize everytime I rotated the tires on the mini-van. The torques are dry torques, NOT wet torques, and even a 100 ft-lbs on "some" studs while very wet, multiple times, can ruin them.

NOT saying to never lube your wheel studs, but do it sparingly and NOT every time, just when needed, remember the torques are dry torques. Since then, only when rust shows up on the studs do I lube them and then just a tiny smear of anti-seize or a drop of oil, I haven't ruined the threads on studs yet using that rule.

I suspect Commanders come with higher quality studs than '91 Mini-Vans, so even a person using excessive lube all the time might NOT recreate what happened on my mini-van, but the principle still applies.

As far as Rotors seizing to hubs, and aluminum wheels seizing to rotors. A little anti-seize every once in a while (NOT every time) goes a long way in preventing that.

NOTE, the FSM for many modern vehicles state NOT to use anti-seize or greas between the rotor and hub. That is because the run-out spec for many modern brakes is less than the width of a human hair, so the fear is using excessive anti-seize or grease will trap a human hair or other debri that will throw the rotor out of run out specs. What I do, I apply the anti-seize and then wipe it off, in fact buff it into the rotor surface on each side just a bit, just to leave behind a slight residue burnished into the surface of anti-seize, nothing sticky. Sure enough that is all that is needed, after that treatment, there is nothing getting trapped in the anti-seize to throw off the run-out, and years later I can pull aluminum wheels off the rotor or the rotor off the hub without a hammer.
 

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I checked it, head size is 21mm. not 19. M14 bolt corresponds to 21mm head normally. Torque is 129 Nm (95 ft lb)
Bumping this as I lost the right front lower bolt on my way home from work after pulling out of gas station.

Had a rattle and put it off thinking it was the top strut nut.

Top bolt was loose too so I removed it and put on the bottom and tightened best I could. Lasted 5mi till I had to tighten it again. Another 5mi and made it home.

Nice adventure on new years eve.
Home depot had the bolt size mentioned above in stock.
 

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Thanks kids. I've been putting it off because the last two times I went to remove a wheel, I've rounded the acorn nut ( I have a 4-way wrench and even though the size should be exact for the nut, it seems that my gorilla hands can round it ).... Perhaps if the weather is nice this weekend I'll go pickup new nuts, a 21mm, breaker bar and plan to curse the gods trying to get them off.. Or I'll take it to a shop and see what they will charge to do the work :)
Add a little pb blaster lubricant on the bolts like 5 mins or less before you got to take them off, itll make your life a whole lot easier.
 

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Add a little pb blaster lubricant on the bolts like 5 mins or less before you got to take them off, itll make your life a whole lot easier.
@Jonnyboy; Welcome to the forum; Please read the New Member Required Reading below; Thank you.

 
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