Front caliper securing bolts torque

As I said, When torquing, I use bolt diameter as a guide...A bolt of similar diameter should not be torqued to a higher setting without risk of it snapping under use. There are exceptions, being wet thread torque, which is generally slightly lower due to the lack of friction between the threads on the bolt and mating threads, and when torquing an aluminium part down, such as a cylinder head, where hot final growth of the head will snap bolts if not compensated for. In a caliper arrangement, the bolts are not loaded in the direction of removal but are side-loaded. The locking compound you see on the threads is put there more to prevent moisture from getting in there and causing the threads to rust. It's more of a thread sealer than a thread locker. Actual torque is more accurately applied by measuring bolt stretch not actual bolt tightness. In a caliper install, it is far less important than in the example of the cylinder head. Providing that the caliper bolts are tight enough to secure the part, and not under so much tension that they are over-stressed to the point that when the part gets hot it will grow enough to snap them, the only other concern is that they will loosen and back out. at 35-40 foot pounds, they will do neither. Tighter than that is inviting the bolts to either snap or tear the threads out of the cast-iron steering knuckle to which they are fastened. At the factory, bolts are installed with air guns...they are set to approximate specifications but are a long way from exact. yet bolts stay in place nicely till they are removed for a first brake service. If you checked the installed torque on the next fifty vehicles coming off the assembly line I'm positive that you would find a three to seven lb difference in each vehicle.
By design, calipers have a "fail safe"...Even with no bolts installed, it is very difficult for them to fall off. I have seen many vehicles that a technician forgot to install the bolts altogether...(not from my shop) in every case, the caliper was noisy, but did not fall off. Not saying that you should not use bolts, but it shows that there is a safety margin there far larger than you could imagine.
I personally have installed calipers on vehicles that need to make super hard stops from speeds of over 300mph...and never torqued a caliper bolt. On road course & round track cars, I would use the same method, but for added safety, would use stainless aircraft wire locks on all fasteners. Even so, I never had a caliper or other bolt loosen or fail and even need the wire to "save" the situation.
This isn't an "I'm right...You're wrong" situation, but I do admire your attention to detail...there certainly is nothing wrong with that. What I'm saying is that even without the specific factory #s, you won't have a problem with your install.
More important to brake service is fluid maintenence ...change fluid out at least once a year...it is hygroscopic...as such, it draws in moisture from the air which can cause fluid to rot system from the inside and can cause it to boil on hard braking under higher concentrations. I flush out my system each year and even with over 300k on it, I've never had an internal component failure caused by rust etc. Synthetic fluids are a good option...they far exceed all manufacturers specs and don't draw moisture as standard dot3&4 fluids do. Aside from proper rotor cooling and use of quality pad material, it's one of the best "up-grades" you can make from a safety and performance standpoint.
Good luck with your car!!!!


As I said, When torquing, I use bolt diameter as a guide...A bolt of similar diameter should not be torqued to a higher setting without risk of it snapping under use. There are exceptions, being wet thread torque, which is generally slightly lower due to the lack of friction between the threads on the bolt and mating threads, and when torquing an aluminium part down, such as a cylinder head, where hot final growth of the head will snap bolts if not compensated for. In a caliper arrangement, the bolts are not loaded in the direction of removal but are side-loaded. The locking compound you see on the threads is put there more to prevent moisture from getting in there and causing the threads to rust. It's more of a thread sealer than a thread locker. Actual torque is more accurately applied by measuring bolt stretch not actual bolt tightness. In a caliper install, it is far less important than in the example of the cylinder head. Providing that the caliper bolts are tight enough to secure the part, and not under so much tension that they are over-stressed to the point that when the part gets hot it will grow enough to snap them, the only other concern is that they will loosen and back out. at 35-40 foot pounds, they will do neither. Tighter than that is inviting the bolts to either snap or tear the threads out of the cast-iron steering knuckle to which they are fastened. At the factory, bolts are installed with air guns...they are set to approximate specifications but are a long way from exact. yet bolts stay in place nicely till they are removed for a first brake service. If you checked the installed torque on the next fifty vehicles coming off the assembly line I'm positive that you would find a three to seven lb difference in each vehicle.
By design, calipers have a "fail safe"...Even with no bolts installed, it is very difficult for them to fall off. I have seen many vehicles that a technician forgot to install the bolts altogether...(not from my shop) in every case, the caliper was noisy, but did not fall off. Not saying that you should not use bolts, but it shows that there is a safety margin there far larger than you could imagine.
I personally have installed calipers on vehicles that need to make super hard stops from speeds of over 300mph...and never torqued a caliper bolt. On road course & round track cars, I would use the same method, but for added safety, would use stainless aircraft wire locks on all fasteners. Even so, I never had a caliper or other bolt loosen or fail and even need the wire to "save" the situation.
This isn't an "I'm right...You're wrong" situation, but I do admire your attention to detail...there certainly is nothing wrong with that. What I'm saying is that even without the specific factory #s, you won't have a problem with your install.
More important to brake service is fluid maintenence ...change fluid out at least once a year...it is hygroscopic...as such, it draws in moisture from the air which can cause fluid to rot system from the inside and can cause it to boil on hard braking under higher concentrations. I flush out my system each year and even with over 300k on it, I've never had an internal component failure caused by rust etc. Synthetic fluids are a good option...they far exceed all manufacturers specs and don't draw moisture as standard dot3&4 fluids do. Aside from proper rotor cooling and use of quality pad material, it's one of the best "up-grades" you can make from a safety and performance standpoint.
Good luck with your car!!!!

Would you care to rate my answer...i do this to keep my mind working and to give people help they would not ordinarily find elsewhere (especially free)..I would do it without ratings, but as long as they are there, it's fun to get good ones!

Would you care to rate my answer...i do this to keep my mind working and to give people help they would not ordinarily find elsewhere (especially free)..I would do it without ratings, but as long as they are there, it's fun to get good ones!