Caliper attachment bolt frozen
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
Caliper attachment bolt frozen
Any ideas on how to get the caliper attachment bolts out?
I purchased a set of powdercoated calipers and just started on the right rear stock caliper removal. Top attachment bolt came right out with an impact, but the bottom attachment bolt won't budge?
Any ideas short of dynamite?
It appears that all the attachment bolts are 21mm. I have been hitting this bolt with my impact for 45 minutes! Also tried my 2-foot long Snap-On Breakover bar - looks like it might break first! I think these are only torqued to 23 ft-lbs according to specs - is that right? Also doused it in PB Blaster.
Will it do any good to keep hitting this with my impact or am I just wasting my time with that?
I purchased a set of powdercoated calipers and just started on the right rear stock caliper removal. Top attachment bolt came right out with an impact, but the bottom attachment bolt won't budge?
Any ideas short of dynamite?
It appears that all the attachment bolts are 21mm. I have been hitting this bolt with my impact for 45 minutes! Also tried my 2-foot long Snap-On Breakover bar - looks like it might break first! I think these are only torqued to 23 ft-lbs according to specs - is that right? Also doused it in PB Blaster.
Will it do any good to keep hitting this with my impact or am I just wasting my time with that?
Last edited by Choreo; Dec 14, 2008 at 07:17 PM.
Racer
Joined: Dec 2002
Posts: 331
Likes: 17
From: Kerrville Texas
The caliper mounting bracket bolts are 125 lb ft of torque, plus have threadlocker.
It will take some muscle, but it will come off. Try heating it with a heat gun. Or possibly putting a bottle jack under the breaker bar and letting the jack apply the force...someone posted this trick a while back and said it worked quite well.
Good luck.
It will take some muscle, but it will come off. Try heating it with a heat gun. Or possibly putting a bottle jack under the breaker bar and letting the jack apply the force...someone posted this trick a while back and said it worked quite well.
Good luck.
Burning Brakes
Joined: Dec 2005
Posts: 831
Likes: 2
From: Silver Spring, MD
I think you are referring to the wrong bolt. The guide pin bolts are only 23 ft lbs (which holds the caliper only). If you are changing out the caliper brakets (which I suspect) they are 125 ft lbs and yes, are a sob to remove. I sprayed with wd-40 and liquid wrench banged on it with a mallet and let it set for 15 mins. finally broke loose with an impact. It will eventually breake loose. If you have room and leverage, the breaker bar should do the same. Others have set up the breaker bar and lowered the car to break the bolt free (should be post on the subject).
Racer
Joined: Aug 2007
Posts: 339
Likes: 0
From: CORONA SO CAL
They are a PITA to break loose. You need to find a way to apply more force. Unless you have a hell of a compressor and impact gun they usually aint worth the metal they are made from. Use the ARMSTRONG method.
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
Thanks for the replies!
I finally got it by heating the bracket with a propane torch and hitting it with the impact again. Not looking forward to 3 more calipers like this!
Hope I have room to get my torque wrench in there to put 125 ft-lbs on those to reinstall! Don't see how I can do this without a lift? Going back on may be harder than getting them off!
Also, I removed the entire caliper as a single unit with the caliper bracket still attached and then removed the caliper guide pin bolts in a bench vice. Is there any reason I cannot just reverse that procedure by assembling the new powdercoated ones in a vice and then just worry about the 2 bracket bolts on the car?
I finally got it by heating the bracket with a propane torch and hitting it with the impact again. Not looking forward to 3 more calipers like this!
Hope I have room to get my torque wrench in there to put 125 ft-lbs on those to reinstall! Don't see how I can do this without a lift? Going back on may be harder than getting them off!
Also, I removed the entire caliper as a single unit with the caliper bracket still attached and then removed the caliper guide pin bolts in a bench vice. Is there any reason I cannot just reverse that procedure by assembling the new powdercoated ones in a vice and then just worry about the 2 bracket bolts on the car?
Last edited by Choreo; Dec 14, 2008 at 09:06 PM.
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
Re-torquing was not as bad as I imagined. Got one on - three to go! If the torque wrench had slipped or a socket had broken would have been at least four busted fingers! So far so good.
Racer
Joined: May 2008
Posts: 316
Likes: 0
From: San Deigo California
On Torque. Remember for the long head bolts, the purpose of torque is to stretch the bolt (or stud) so it is sort of like a mini-spring to hold the head tight in various temperatures.
For other bolts, the exact torque is total BS. It's just a way of making sure a bolt is tight, but not over tight. (Yes it is a feel good to torque everything, but not needed for most bolts). As for the caliper bolts, 125 ft-lbs, means "get it tight".
For other bolts, the exact torque is total BS. It's just a way of making sure a bolt is tight, but not over tight. (Yes it is a feel good to torque everything, but not needed for most bolts). As for the caliper bolts, 125 ft-lbs, means "get it tight".
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Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
Two calipers down - two to go.
Going back together is not so bad... getting the bracket bolts loose is a biache! May have to find a heavier duty impact if I ever tackle something like this again! So far torch and biting down on leather has been working together with much cussing.
Going back together is not so bad... getting the bracket bolts loose is a biache! May have to find a heavier duty impact if I ever tackle something like this again! So far torch and biting down on leather has been working together with much cussing.
Le Mans Master
Joined: Dec 2000
Posts: 9,915
Likes: 1,870
From: Hot Springs AR
Also, bolts typically will take more torque to free up than the spec number.
HTH, and have a good one,
Mike
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
That's my first suggestion. A cheapo impact wrench (<$50), even though it may advertise huge torque numbers, can sometimes not even generate 100 lb-ft. My Ingersoll-Rand 1/2" impact wrench will spin these bolts off every time, although it can be a tight fit on the rear wheel caliper bracket bolts.
Also, bolts typically will take more torque to free up than the spec number.
HTH, and have a good one,
Mike
Also, bolts typically will take more torque to free up than the spec number.
HTH, and have a good one,
Mike
Features dual speeds of 1250 bpm and 9500 rpm, 1/2 in. Chuck Capacity , 4 position torque with 50-400 ft./lbs. working torque and a maximum torque of 450 ft./lbs. forward and 600 ft./lbs. reverse. Also features engine reversibility, an average air consumption of 4.8 cfm,1/4 in. air inlet and 3/8 in. minimum hose size.
Guess that's not enough?
Pro
Joined: Apr 2007
Posts: 650
Likes: 4
From: Pittsburg Ca.
That's my first suggestion. A cheapo impact wrench (<$50), even though it may advertise huge torque numbers, can sometimes not even generate 100 lb-ft. My Ingersoll-Rand 1/2" impact wrench will spin these bolts off every time, although it can be a tight fit on the rear wheel caliper bracket bolts.
Also, bolts typically will take more torque to free up than the spec number.
HTH, and have a good one,
Mike
Also, bolts typically will take more torque to free up than the spec number.
HTH, and have a good one,
Mike
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
All I have is a new Craftsman Professional 1/2" Drive Impact with the following specs...
Features dual speeds of 1250 bpm and 9500 rpm, 1/2 in. Chuck Capacity , 4 position torque with 50-400 ft./lbs. working torque and a maximum torque of 450 ft./lbs. forward and 600 ft./lbs. reverse. Also features engine reversibility, an average air consumption of 4.8 cfm,1/4 in. air inlet and 3/8 in. minimum hose size.
Guess that's not enough?
Features dual speeds of 1250 bpm and 9500 rpm, 1/2 in. Chuck Capacity , 4 position torque with 50-400 ft./lbs. working torque and a maximum torque of 450 ft./lbs. forward and 600 ft./lbs. reverse. Also features engine reversibility, an average air consumption of 4.8 cfm,1/4 in. air inlet and 3/8 in. minimum hose size.
Guess that's not enough?
Bill
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 6,774
Likes: 363
From: Midland TX
Once I started using a Propane Torch on the connections they finally all came loose.
Here are the before and after of the calipers...
Le Mans Master
Joined: Dec 2000
Posts: 9,915
Likes: 1,870
From: Hot Springs AR
Glad the "thermal breaker bar" worked for you.
Have a good one,
Mike
