Caliper Bracket Bolts
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Burning Brakes
Joined: May 2001
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From: Austin TX
Caliper Bracket Bolts
In the manual, it says to torque these to 166+/_ 15ft lbs. The way it is written in the service manual, I am not sure if it means 166 plus or minus 15, meaning 151-181 ft lbs, or just 15lbs. Anyone know which it is?
Trey
Trey
Melting Slicks
Joined: Sep 2003
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From: N. Babylon NY
Originally Posted by Trizney
In the manual, it says to torque these to 166+/_ 15ft lbs. The way it is written in the service manual, I am not sure if it means 166 plus or minus 15, meaning 151-181 ft lbs, or just 15lbs. Anyone know which it is?
Trey
Trey
Steven
Drifting
Joined: Sep 2003
Posts: 1,363
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Warning - Helm Torque Is Wrong - S/b 137-140!
Originally Posted by Trizney
In the manual, it says to torque these to 166+/_ 15ft lbs. The way it is written in the service manual, I am not sure if it means 166 plus or minus 15, meaning 151-181 ft lbs, or just 15lbs. Anyone know which it is?
Trey
Trey
Please do a search in the forum archives --
You will find a lengthy disscussion about the manual being incorrect
on the torque and how at that torque it either breaks the bolts or stretches the threads.When I did ours in November 1993, I found discussion threads which discussed someone actually doing tests with the factory bolts.
Elite Torch Red Member
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
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Originally Posted by Strick
Anybody know why the manual says to replace those bolts every time you remove them? Is it the compound they put on the threads or just fatique of the bolts?
Paid about $28 for all 8.
Drifting
Joined: Sep 2003
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
possibly due to earlier models recall
Originally Posted by Strick
Anybody know why the manual says to replace those bolts every time you remove them? Is it the compound they put on the threads or just fatique of the bolts?
I would also guess it was driven by the early models (pre 92?) recall.
Since GM had to increase the torque of the bolts (albeit the manual is in error on the torque) and add the 'locktite', which together with the front brakes taking a greater load/shock, replacement every time may have been the easy way out of the recall problem.
Try doing a search of the old discussion threads, it might have said specifically why in one of them...
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The GM bolts come with a threadlocker already applied. Rather than have a tech apply new threadlocker each time the bolts are removed and reinstalled, it was easier (and GM made more money) to just use new bolts.
I reuse the OEM bolts 3 times before tossing them. 155 ft-lbs is correct for the front bracket bolts (the rear bolts are 70 ft-lbs) and I use Locktite Blue threadlocker on them and tighten in two steps quickly.
Don't use red Locktite on the bolts as heat is required to remove the bolts!!
theadmiral94-- Do you have a link or info (other than the CF post) regarding a TSB or some other document from GM concerning caliper bolt bracket bolt torque?
I reuse the OEM bolts 3 times before tossing them. 155 ft-lbs is correct for the front bracket bolts (the rear bolts are 70 ft-lbs) and I use Locktite Blue threadlocker on them and tighten in two steps quickly.
Don't use red Locktite on the bolts as heat is required to remove the bolts!!
theadmiral94-- Do you have a link or info (other than the CF post) regarding a TSB or some other document from GM concerning caliper bolt bracket bolt torque?
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Drifting
Joined: Sep 2003
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Originally Posted by c4cruiser
theadmiral94-- Do you have a link or info (other than the CF post) regarding a TSB or some other document from GM concerning caliper bolt bracket bolt torque?
However your point is well taken, one would think there might have been something if it was truely an error in the manual.
However the CF posts I read 2 years ago were quite compelling (one guy actually did almost a certified test of the bolts at different torques and then very precise measurements of the bolts thereafter).
Also, the Chilton manual was probably just quoting the Helm manual when it noted when it noted: 137 ft lbs for 1988-1989 (and 151-181 ft lbs for 1990-1996) --
I felt the CF posts were the better guidance to follow, hence why I only torqued ours to the 137-139 range -- thankfully after about 3k miles, no problems...
BTW, you mentioned 155, but my manual and apparently Trizney's note it as 165/166 (+/- 15) respectively -- why would the low end of the recommended torque be more correct?
Melting Slicks
Joined: Sep 2003
Posts: 2,270
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From: N. Babylon NY
So is 155ft.lbs. okay for the front?
So is 155ft.lbs. okay for the front? I torque mine to 155ft.lbs. everytime I change my rotors (after about 4 races). Also just upgraded to GS calipers.
I wire wheel the bolts and apply locktite and never had a problem.
But now I wonder if this is wrong.
Thanks for the info,
Steven
I wire wheel the bolts and apply locktite and never had a problem.
But now I wonder if this is wrong.
Thanks for the info,
Steven
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Oops! The torque for the front caliper brackets on my 92 as shown in the service manual is 165 +/- 15 ft-lbs. My bad-typo error.
The manual for my 87 says 133 ft-lbs for the front caliper brackets. There had to have been some reason why GM changed the torque values over the years. Larger diameter rotors? larger pad size in the later cars? Bolt size? Hard to say what the engineers were thinking but if they made such a big change in torque values (at least 15% more) over the years, there must have been some good reason for it.
I also take a wire wheel to my bolts (both the bracket bolts and the guide pin bolts on the 87) and clean them up before I apply new threadlocker. I also chase the threads on the brackets themselves to make sure there is no residue from earlier applications.
The manual for my 87 says 133 ft-lbs for the front caliper brackets. There had to have been some reason why GM changed the torque values over the years. Larger diameter rotors? larger pad size in the later cars? Bolt size? Hard to say what the engineers were thinking but if they made such a big change in torque values (at least 15% more) over the years, there must have been some good reason for it.
I also take a wire wheel to my bolts (both the bracket bolts and the guide pin bolts on the 87) and clean them up before I apply new threadlocker. I also chase the threads on the brackets themselves to make sure there is no residue from earlier applications.