Asura

RE your brakes, 15 psi is plenty for the Motive bleeder.

Do you have speed bleeders?
What brake fluid and pads are you using?
Why did you bleed with cap on?
Did you recently switch the brake lines for any reason?
Did you check all hard fittings and banjos?

freq

twohoos

It's easy to break a stud removing a lug; in fact isn't that usually how they break?? Basically some grit gets into the threads during a wheel change, and the next time you try to get it off, the lug "catches" the grit in the wrong way and seizes. It's just bad luck (and maybe a little carelessness not keeping things clean when changing wheels); it doesn't really imply anything about the strength of the rest of the studs.

I've never heard of properly-torqued bolts failing during use?? Now that would be a real cause for concern, and an indication of something else in the suspension or drivetrain being seriously wrong. But if you suspect that something like that is the cause, then obviously the car's just unsafe, no matter how many lugs you've got. You could install high-strength studs and lugs, but at best you're just shifting the failure point to something else in the driveline.

rlaifatt

If you had bled too low and got air in the master cylinder at any time, then regular bleeding wont remove it. That happened with me couple years ago, and the solution given by Davepk that worked is to activate ABS several times then bleed. Need to find a safe place to brake/activate ABS of course. Don't recall if I had to do this more than once.

Orthonormal

Clarification: these were sets of bolts holding suspension elements on. One had the first bolt back out, then the remaining bolts ripped out. The other had one bolt break resulting in increased fatigue in the other two, which both failed at once.

To tell the truth, I've never seen a stud break, even when cross-threaded -- until intentionally broken using a breaker bar (aptly named) and a heck of a lot more force than one would use to install or remove a lugnut. So I don't really know how they "usually" fail -- in my experience there is no "usually", so when one does fail it makes me think it could have been weakened somehow. It seems strange to me that a piece of grit would generate enough resistance to snap a stud -- and that the person removing the wheel would oppose that resistance with enough force to snap the stud without knowing that something was up.

Usually, when this happens to you, do you realize that the nut is stuck, apply more force, and that's when it snaps? Or are you just going about your routine, zipping off the nuts as usual, and the stud just breaks?

BroxS2K, how much force were you applying when the stud broke?

cthree

Thanks for the clarification on that because the idea of snapping studs due to normal loading is nuts

Breaking off a stud is VERY EASY. I've done it removing them and when it happens you know it's happening and there is nothing you can do about it. You are screwed. You can break the stud just like you can break any bolt or screw. Don't tell me you've never tightened a bolt and felt the limp sinking feeling of the head twisting off. Same thing. The studs are made of normal steel and so are the lugs. Add some water, air, brake dust, aluminum wheels and time and the nuts will seize onto the studs such that when you try to remove them...you know the rest. By the way, it is always the 5th and last nut that seizes.

CoralDoc

Breaking studs occurs pretty regularly. Although this is against the conventional wisdom of torquing clean, dry fasteners, I'm a big proponent of using a small amount of anti-sieze on wheel studs and lug nuts. In my opinion, you are better able to correctly torque non-galled and non-siezed fasteners. Plus you get the added benefit of reducing the likelihood of breaking a stud.

Regarding the brake system, it should be easy to get a firm pedal, and I don't see how having the cap on the reservoir would lead to sponginess. The cap is vented and even when installed should not prevent proper bleeding. There is something else wrong that needs to be dealt with before I'd even drive the car on the street, let alone the track.

cthree

I've actually read in a race car engineering book that using anti-seize is recommended and I've done it but stopped. The problem I had was that the nuts were backing off even when torqued to the correct setting. I had this problem last year where when making tight circles I would get a clicking and popping sound from the rear-end. I thought it was a CV joint or axle nut but it turns out it was loose nuts.

It seems that using anti-seize or grease on the studs to prevent oxidation is a great idea if the lugs get re-torqued regularly. I wonder if using removable Loctite would have the same anti-oxident benefit but also not be so slippery. My front studs are caked with white oxidation and I very concerned about this binding up the nuts.

CoralDoc

I'm avoiding an easy tasteless joke ...

But seriously, it is unsettling that you experienced fastener loosening even after correct torque was applied to the lug nuts. I have been using very thin applications of anti-sieze on the studs on my S2000 and Miata and have yet to have them loosen up on me.

Ludedude

Yep, no loose nuts here after anti-seize either.