Don’t over-torque things!
May 4, 2010 at 6:29 am #3923eternal05Participant
It should go without saying, but if you work on your own bike, make sure you figure out how hard things need to be torqued. I just wasted two days of my life recovering from a sheared brake bleeder valve broken off level in one of my front brake calipers. I wasn’t really paying attention and, seeing exposed threads, thought it needed to go in more. It didn’t. Right in the middle of my friend saying “Hey, you know that the threads don’t have to be in all the wa—” SNAP. I looked up the torque rating later: 5 lb-ft. Five. I was probably applying 80. No wonder.
Anyway, six different-diameter screw extractors, a left-handed drill bit, a broken drill chuck, and ten hours of cussing later, I’m back in business. Luckily I got it out in time, but that could have cost me a brake caliper ($$$) and a track day ($$$). Make sure to learn from my mistakes!May 4, 2010 at 1:51 pm #26159briderdtParticipant
When you remove a bolt, grease it before putting it back in.
The forces to move a dry bolt are a lot higher than a greased one, and even though it may seem like the proper torque, what you’re feeling is the dry static friction. That grease won’t make the bolt loosen under use — that’s why there are torque values to begin with.May 4, 2010 at 6:50 pm #26167madjak30Participant
Don’t forget that if you lube your threads, there is usually a slightly different torque that you should use. The torque setting in your book is for dry threads, but it may list a torque for thread lube. I would recommend using something to act as an anti-seize, since most of your torque spec’d bolts on the bike will be into aluminum…dissimilar metals will seize from the chemical reaction, given enough time.May 4, 2010 at 8:21 pm #26169
A very large disposable syringe fitted with a short length of gas line tubbing is a great way to bleed air from the brake hydraulics, you push the gas line tubbing onto that bleeder screw the one you oops broke off ) loosen the bleeder slightly and push clean brake fluid backwards through the system. …difficult to describe better in words but this technique overcomes the problem of bleeding air from an inherently low point in the brake system.
Loctite offers some excellent product to accommodate all of the aforementioned screw thread problems and a small bottle goes a very long way.
Wheel spokes are something that you should never try to adjust dry, as they have a propensity to corrosion and seizure, spray liberally with WD40 a full 10 minutes before making any adjustments and save yourself a ton of grief. Invest in a real spoke wrench.May 4, 2010 at 10:40 pm #26171Jeff in KentuckyParticipant
I use this for a lot of threads- it is made for aluminum heads with a lot of heat and vibration, for spark plugs that sometimes got very stuck or very stripped in the old days. The blue and red types of Loctite (or other brand) are also good for nuts and bolts that might loosen from vibration- make sure you know which is which- the one requires heat before loosening, but resists vibration better.May 4, 2010 at 10:57 pm #26173gitchy42Participant
Just about every torque spec I’ve seen assumes that you are working with DRY threads, unless marked otherwise. Although, if you see two or three different torque specs for the same bolt usually it is the ft/lbs and NM specs or dry, wet, metric specs.
Unfortunately I believe that any anti-seize is considered a lubricant, so you would have to use the ‘wet’ torque specs. But like madjak said, dissimilar metals tend to bind up and gall, especially stainless going into aluminum.May 4, 2010 at 11:07 pm #26175gitchy42Participant
Remember when using loctite that the RED Loctite is designed to not come loose, ever. Usually you can break it free, but not always before you break somethings else. I always suggest using the BLUE Loctite.May 5, 2010 at 5:29 am #26186megaspazParticipant
+1 on the blue loctite.May 5, 2010 at 6:46 am #26189RabParticipant
Didn’t you know?
Fasteners on modern motorcycles are made of cheese.May 5, 2010 at 10:12 pm #26207
Do not try this brake bleed process on ABS equipped bikes. You can mess up the system.May 5, 2010 at 11:25 pm #26212
Not to argue your point, I have no first hand experience wrenching ABS bikes. But how so ?May 6, 2010 at 1:47 am #26214
The valves in the pump body are designed to allow pressure to go one way at a certain time… depending on the design of the ABS sending a back flow can mess the seals up on the valves or even the pressure sensors. Not to mention un intentionally trap air inside the body itself which is a huge pain to get out.
In the auto world especially in some cases you get the shade tree mechanic that makes this mistakes you have to get it bled out Via a computer that handles ABS.May 6, 2010 at 1:50 pm #26224
I read that some ABS systems require special equipment to effectively bleed the system irregardless of the process applied.
As to unintentionally trapping air inside the system, I kinda assumed we were bleeding the thing because there was already air throughout the system, as would be the case if you had just drilled out the caliper to extract a broken bleeder screw.
still puzzled though …if back flow could not happen when the brakes are released, wouldn’t that make your brakes one time use?May 6, 2010 at 6:42 pm #26230
Wasn’t really commenting on OP just wanted to keep some from a potential mistake. Brakes don’t really have back pressure so to speak. Just pressure then normal pressure (compression,decompression). When the brakes are applied the mechanism pushes on the fluid which has an effect like pushing on a plugged syringe…only the piston has give and that pressure forces the piston out to relieve excessive pressure and blowing a line or master body. Let off the pedal or lever and that pressure relaxes. Little to no back movement. Add ABS and you add a pump body that keeps a preset pressure in the system and monitors it. When it detects an excessive amount in a short time it springs into action by modulating the pressure. The only time more fluid is used is to fill the extra room left when the pads wear thinner
Another thing to add is there is no suction or back pressure to get the pads off the rotor. That job is left to the piston cup seal. It flexes with application then draws itself back to its original state from the beginning.May 7, 2010 at 7:10 am #26253eternal05Participant
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