Dae Posted February 8, 2012 Share Posted February 8, 2012 About to replace my front tire for the 5th time, it states in the manual to replace with new brake caliper mounting bolt each time they are removed. I’m still using the original bolt, should I replace them with new ones or just keep using the same old bolt? How often do members here replace the bolt? Link to comment Share on other sites More sharing options...
Member Contributer IntAceptor Posted February 8, 2012 Member Contributer Share Posted February 8, 2012 Ahhhh lawyers. Never did replace a bolt and did the same job you are doing 20 or more times. Just make sure they are properly torqued and a bit of Lock-Tite blue wouldn't hurt. Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 8, 2012 Share Posted February 8, 2012 How often? Never since 1984 on various motorcycles. Clean the threads male/female, apply Blue locktite, torque wrench, ride. I would only replace one if it were buggered somehow, but by then, you probably would know you already did something wrong to cause that. (moved to "maintenance questions" forum) Link to comment Share on other sites More sharing options...
Dae Posted February 8, 2012 Author Share Posted February 8, 2012 Thank You for your responses, I guess I can keep using the same bolts and not having to worry about breaking apart. Link to comment Share on other sites More sharing options...
Member Contributer MBrane Posted February 8, 2012 Member Contributer Share Posted February 8, 2012 Hold them up to a rule. If there is a visible gap between any of the threads & the straightedge or visible differences in thread pitch (distance between threads themselves) replace 'em. This indicates that they are beginning to lose their "stretch" from too many torque cycles, and have become brittle i.e. they could snap off the next time you torque 'em down or worse the next time you get on the brakes hard. Like was mentioned above Honda's lawyers are the ones that suggest replacing them every time. Link to comment Share on other sites More sharing options...
ericlw Posted February 8, 2012 Share Posted February 8, 2012 locktite? ive never used locktite on my brake bolts and they are never loose when i remove them to do mainatence,if you torque the right its not needed imo.never replaced any of the bolts either. Link to comment Share on other sites More sharing options...
Monk Posted February 8, 2012 Share Posted February 8, 2012 The people that write the manuals should replace the lawyers with mechanics. Link to comment Share on other sites More sharing options...
Member Contributer Bent Posted February 8, 2012 Member Contributer Share Posted February 8, 2012 These bolts don't have a lot of torque spec.ed 20# if I remember right. Yes, on brakes I used Loctite. Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 9, 2012 Share Posted February 9, 2012 locktite? ive never used locktite on my brake bolts and they are never loose when i remove them to do mainatence,if you torque the right its not needed imo.never replaced any of the bolts either. Maybe not, but a drop of the blue (medium strength) stuff certainly wouldn't hurt, expecially with important stuff that like, holds your wheels 'n brakes on 'n stuff. Helps ME sleep better anyhow. The OEM bolts, when new, come with a dry threadlocking agent already applied to the threads. Link to comment Share on other sites More sharing options...
AB-Oz Posted February 9, 2012 Share Posted February 9, 2012 I used loctite (243?) on my caliper bolts, then when I frankenviffered I got some new bolts...and I've had them out and in a couple of times since then. Link to comment Share on other sites More sharing options...
Beck Posted February 9, 2012 Share Posted February 9, 2012 Are these wht they call "Stretch Bolts"? Same as with engine block studs?.Once they are torqued to specs they stretch to design spec limits and should not be reused.......per the engineers........ I myself never repalced mune when I de-mounted my calipers. Still alive and riding....... Beck 95 VFR Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 9, 2012 Share Posted February 9, 2012 Stretch bolts, like cylinder head bolts, are usually spec'd for tightening like so: "Torque to (XX) ft/lbs, then turn bolt an additional 90 (or whatever) degrees of rotation". I am using grade 12.9 socket head cap screws for my calipers so I'm not worried about them. They're just about the strongest bolts you can buy without getting into exotic materials and $$$. Link to comment Share on other sites More sharing options...
Aeromagic Posted February 9, 2012 Share Posted February 9, 2012 I've been replacing them because they are inexpensive from Honda. I've never seen the old ones stretched or deformed in any way - I don't think I'd hesitate to use them again if the new ones were more expensive. I wonder if a dealership would replace them on a tire change - it's stated pretty clearly in the manual, but like stated above I think lt's got to do with lawyers writing the manuals. Link to comment Share on other sites More sharing options...
Member Contributer Cogswell Posted February 9, 2012 Member Contributer Share Posted February 9, 2012 When re-using the caliper bolts, it's important to get any of the old Loctite off the threads, both male and female. I have some dental picks and a selection of brass brushes I use for that purpose. The dental pick gets the bulk of it off and the brush(s) do a final cleanup. I don't often find much on the female threads on the fork tubes, but when I do, I can usually get it out with the dental pick. If not, I'll chase the threads with a tap for that purpose but only had to once. Clean threads are the only way to get accurate torque readings and maybe why Honda recommends replacement of the old ones. Link to comment Share on other sites More sharing options...
Guest Posted February 9, 2012 Share Posted February 9, 2012 Another possibility is to safety- wire them Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted February 9, 2012 Member Contributer Share Posted February 9, 2012 Oh yeah, blame the lawyers...when it's clearly the engineers' fault! The Honda bolts for which the "replace each time" instruction is provided are also identified by Honda as "ALOC" fasteners. These are fasteners that are designed to exert maximum clamping force by being tightened to a higher torque value than ordinary steel fasteners. In essence, they are (like certain other critical-application bolts mentioned above) designed to stretch slightly upon installation in order to exert the maximum clamping force. How many times can you stretch a bolt? Do you ask a lawyer, or an engineer? Given the rarity of both caliper bolt replacements and caliper bolt failures I think we can fairly safely say that the requirement of replacement each time is probably a bit too conservative. I used to rhetorically ask why so few Honda dealers had caliper bolts in stock if they were actually following Honda's own servicing instructions (they should have had them in bulk dispensers...) However, a stretched bolt will very likely fail if stretched enough, often enough. And as I have noted above, these particular bolts are supposed to stretch even when torqued to the correct torque (not to mention what happens if you overtorque them or use thread lock/anti-seize on them!) So if you don't know who's been wrenching on your caliper bolts since they were new, you might want to think about springing for a set of fresh ones--or maybe switch to titanium. Precisely why Honda decided to use ALOC fasteners on its brake calipers I do not know. But I think it exceedingly unlikely that this was a decision made by lawyers... Ciao, Link to comment Share on other sites More sharing options...
Beck Posted February 9, 2012 Share Posted February 9, 2012 Oh yeah, blame the lawyers...when it's clearly the engineers' fault! The Honda bolts for which the "replace each time" instruction is provided are also identified by Honda as "ALOC" fasteners. These are fasteners that are designed to exert maximum clamping force by being tightened to a higher torque value than ordinary steel fasteners. In essence, they are (like certain other critical-application bolts mentioned above) designed to stretch slightly upon installation in order to exert the maximum clamping force. How many times can you stretch a bolt? Do you ask a lawyer, or an engineer? Given the rarity of both caliper bolt replacements and caliper bolt failures I think we can fairly safely say that the requirement of replacement each time is probably a bit too conservative. I used to rhetorically ask why so few Honda dealers had caliper bolts in stock if they were actually following Honda's own servicing instructions (they should have had them in bulk dispensers...) However, a stretched bolt will very likely fail if stretched enough, often enough. And as I have noted above, these particular bolts are supposed to stretch even when torqued to the correct torque (not to mention what happens if you overtorque them or use thread lock/anti-seize on them!) So if you don't know who's been wrenching on your caliper bolts since they were new, you might want to think about springing for a set of fresh ones--or maybe switch to titanium. Precisely why Honda decided to use ALOC fasteners on its brake calipers I do not know. But I think it exceedingly unlikely that this was a decision made by lawyers... Ciao, Heck, I've heard of safety factors of "5" being used by engineers on their design for many things, so, the bolts might be way over spec'd to start with..... Brakes + the litigious state of our society these days?...I wouldn't doubt if that's the case.... Beck 95 VFR Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 9, 2012 Share Posted February 9, 2012 If it was a helicopter, I could see a safety factor of about 1.3 or so, due to weight restrictions and such, and the stringent service intervals assigned to aircraft. Land-based vehicles for public transport are gonna have a hell of a lot larger safety factor built in. And as JZH said, if the Honda dealers followed the service manual recommendation TO THE LETTER, they would have a 45 foot van parked out back of the dealership, chock full of caliper bolts at the ready. So why do they need to order them in when you go to the parts counter???? Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 9, 2012 Share Posted February 9, 2012 If a guy were super worried about the bolts, replace with grade 12.9 socket head cap screws and be done with the issue forever. Titanium bolts are rated to around 120,000 PSI tensile strength, depending on the specific alloy. Grade 12.9 are rated slightly over 175,000 PSI IIRC, shear strength is around 0.5 to 0.6 of the ultimate tensile strength, and caliper bolts are loaded in the shear plane during braking, so an increase in tensile strength of the bolts will have a positive effect on the shear strength. I am not an engineer, just information I have gleaned off the internet from bolt manufacturer's websites. Black bolts in the photo are Grade 12.9, as are all the bolts for my triple clamps and handlebars. Link to comment Share on other sites More sharing options...
Veefer800Canuck Posted February 9, 2012 Share Posted February 9, 2012 Also, the bolts are anchored into ALUMINUM, instead of cast iron like an engine block with TTY bolts. I think the female threads in the caliper would probably strip out before the bolt reached it's plastic deformation point. I doubt that given the tensile strength of the aluminum caliper material (not sure about the caliper, but typical aluminum bolts = 55,000 PSI) that the steel caliper bolt would stretch into plastic deformation given the tensile strength of the bolts at 120-175,000 PSI, depending on the material quality. Note the procedure for TTY bolts, none of which is in the FSM for the caliper bolts. I still believe that the "new bolt" advice is a CYA move by Honda, and to ensure that locking agent is present on the threads, as it is already applied to the new bolts. Link to comment Share on other sites More sharing options...
Member Contributer MBrane Posted February 10, 2012 Member Contributer Share Posted February 10, 2012 Any fastener that is subjected to multiple torque cycles will eventually stretch, and fail. How many cycles it takes depends on many factors that are difficult to predict. That's why you inspect 'em or simply replace 'em to be "safe". Link to comment Share on other sites More sharing options...
Member Contributer dirtbag Posted February 10, 2012 Member Contributer Share Posted February 10, 2012 This. The mating surface between the caliper and carrier is not a critical fit. Nor is there any flatness or pinch requirements. Personally, I have never used any thread adhesive. Considering that the oem bolts come with a dry threadlock, it stands to reason that bad things will happen if the bolt comes loose. Cheap, easy insurance. After reading this thread, I have a feeling I will be using a drop or two of loctite on my bolts next time my calipers are off. I already have some in my toolbox, so it would be foolhardy not to, no? Also, the bolts are anchored into ALUMINUM, instead of cast iron like an engine block with TTY bolts. I think the female threads in the caliper would probably strip out before the bolt reached it's plastic deformation point. I doubt that given the tensile strength of the aluminum caliper material (not sure about the caliper, but typical aluminum bolts = 55,000 PSI) that the steel caliper bolt would stretch into plastic deformation given the tensile strength of the bolts at 120-175,000 PSI, depending on the material quality. Note the procedure for TTY bolts, none of which is in the FSM for the caliper bolts. I still believe that the "new bolt" advice is a CYA move by Honda, and to ensure that locking agent is present on the threads, as it is already applied to the new bolts. Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted February 11, 2012 Member Contributer Share Posted February 11, 2012 Also, the bolts are anchored into ALUMINUM, instead of cast iron like an engine block with TTY bolts. I think the female threads in the caliper would probably strip out before the bolt reached it's plastic deformation point. I doubt that given the tensile strength of the aluminum caliper material (not sure about the caliper, but typical aluminum bolts = 55,000 PSI) that the steel caliper bolt would stretch into plastic deformation given the tensile strength of the bolts at 120-175,000 PSI, depending on the material quality. I still believe that the "new bolt" advice is a CYA move by Honda, and to ensure that locking agent is present on the threads, as it is already applied to the new bolts. I don't know where my back-up material is, so I'm not going to wing it and say anything more about clamping force, but when I noticed that Honda's torque value for its ALOC fasteners was higher than its "normal" torque value for M8 fasteners I decided that there was probably something more to this than just thread lock. After all, Honda could have just specified "use Honda Bond A" (or whatever is the OEM equivalent of Loctite blue) if they were mainly concerned with the fasteners coming loose. As we know, a lot more fasteners would get loctited than would ever get replaced with new... Ciao, Link to comment Share on other sites More sharing options...
Member Contributer MBrane Posted February 13, 2012 Member Contributer Share Posted February 13, 2012 Also, the bolts are anchored into ALUMINUM, instead of cast iron like an engine block with TTY bolts. I think the female threads in the caliper would probably strip out before the bolt reached it's plastic deformation point. I doubt that given the tensile strength of the aluminum caliper material (not sure about the caliper, but typical aluminum bolts = 55,000 PSI) that the steel caliper bolt would stretch into plastic deformation given the tensile strength of the bolts at 120-175,000 PSI, depending on the material quality. I still believe that the "new bolt" advice is a CYA move by Honda, and to ensure that locking agent is present on the threads, as it is already applied to the new bolts. I don't know where my back-up material is, so I'm not going to wing it and say anything more about clamping force, but when I noticed that Honda's torque value for its ALOC fasteners was higher than its "normal" torque value for M8 fasteners I decided that there was probably something more to this than just thread lock. After all, Honda could have just specified "use Honda Bond A" (or whatever is the OEM equivalent of Loctite blue) if they were mainly concerned with the fasteners coming loose. As we know, a lot more fasteners would get loctited than would ever get replaced with new... Ciao, Anything added to the threads of a fastener is going to have an effect on your torque reading whether locker, anti-seize compound, or plain old oil. If you're re-using the stock bolts with the factory thread lock removed (which is not easy to do!) a bit of blue Loctite certainly won't hurt, and it's lubricating properties would mean you'd need to up the torque slightly over standard to compensate for the lubricated threads. Of course Loctite won't do you any good if the bolt snaps off, and makes it harder to extract the remains. Never had a caliper bolt loosen up on me. I just make sure they're clean, and torque 'em just to spec. Had the calipers off many times now, and the bolts still check out fine. I should probably have some replacements handy though as it's only a matter of time until I find them stretched upon removal. Link to comment Share on other sites More sharing options...
Member Contributer motormike Posted October 12, 2012 Member Contributer Share Posted October 12, 2012 I had new tires mounted and installed the wheels last night with help from a friend. The manual says to "install the right brake caliper and tighten the NEW mounting bolts to the specified torque." Do you use NEW bolts? Enlighten me O' VFR Jedi Master. Link to comment Share on other sites More sharing options...
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