I’ve just returned from a long drive (1500km), where I experienced major brake fade on two separate steep winding descents. Today I decided to rotate the tyres and broke 2 from 4 wheel studs trying to get the first front wheel off. Would this mean that the shop may have over torqued the wheel nuts when they did the brakes?

No - unfortuneately it just means the under paid guy you dont give a rats just held the rattle gun there until he finished picking his nose.

Curse of the enthusiast those rattle guns.

As for brakes do you have drums all round??

If so not much you can do except for changing to discs.

Maybe a good quality fluid replacement.

The car has 4-stud disks, I guess they used the cheapest asbestos free pads, but that isn’t the issue.

What I’m asking is: would wheel studs stretch if over torqued when the brakes are overheated.

I don't know about stretchy studs, but I do know that brake fade on really long descents (like the one going down the Clyde Mountain towards Bateman's Bay) is normal and even happens in modern cars with all round disc brakes. Normal, but not good: you should minimise it as much as possible.

Try to alter your driving technique on really long descents to minimise use of the brake pedal so the brakes don't get so hot. Use engine braking: put it in 3rd or even 2nd gear, the engine will rev high and you won't need to use the brake pedal except for the really steep bits. Go slower: the engine braking trick works better in 2nd than in 3rd. Who cares if you build up a long line of traffic behind you, they should be thanking you for saving their brakes as well as yours!

What I’m asking is: would wheel studs stretch if over torqued when the brakes are overheated.
I don't think you could yield the studs (maximum stress that can be applied before permanent deformation), I think the thread would pull from the hub before that would happen.

On the way down from the North Brother there are only steep bits, and steeper bits. I was in second all the way hence here telling the story.

Speedster,
The nuts budged and went a few turns before tightening up again, there I gave up and tried going back, and the bolt snapped. I was only using a standard wheel brace.

Is there any engineering / metallurgical explanation for this?

If they turned a bit and then got stuck again, is it possible that the thread on the outside end was rusty/damaged?

Nah, there’s zero corrosion on these studs / nuts.

It seems the problem was most likely caused by contaminants on the thread, and since the receipt said that they cleaned and inspected the brakes also, the shop agreed to repair it free of charge.

Cool - good that they're fixing it for free.

Lemme guess - when you get it home, you'll be loosening the nuts and torqing them correctly!

Should use some molly grease(the shiny blackish stuff) on teh threads and chamfers as well. Stops them binding

Hi

If your using stock steel wheels they will cause the brakes to fade, alloy wheels absorb & disapate heat better. Try some Bendix metal kings, I use them and they dont were out discs as some people say.

1302Steve

I really like the look of stock steelies or mangels, so that’s not going to help. I heard that metal kings do wear your disks, mainly from owners of late model non vw cars though. Also heard that car manufacturers in particular Holden use softer materials for rotors of late for better friction so that may be the reason. So I’ll give the metal kings a go on my vw next time.

BTW: North Brother Mountain/lookout is just off the Pacific HWY on the way to Nambucca (from Sydney) if anyone is brave. Nice views, but be careful.