Stuck brake disc screw
Discussion
Been trying to change my brake disks for a couple of weeks
done the back ok
but the fronts the torx screws holding the disks on were very soft and corroded
they are a t50 head, the first one just got completely chewed up, i have tried to use a screw extractor set on it, but that snapped off as soon as it started to bite, so now i have a bit of carbon steel in the way i can seem to get out, i've tried redrilling but just get nowhere
what else can i try?
if i take it to a garage what are they likely to be able to do
done the back ok
but the fronts the torx screws holding the disks on were very soft and corroded
they are a t50 head, the first one just got completely chewed up, i have tried to use a screw extractor set on it, but that snapped off as soon as it started to bite, so now i have a bit of carbon steel in the way i can seem to get out, i've tried redrilling but just get nowhere
what else can i try?
if i take it to a garage what are they likely to be able to do
Assuming...
1.) it's a countersunk screw
2.) you are scrapping the brake disk
3.) you have an angle grinder
Grind through the disk in the area around the screw. Go carefully, and grind until the head of the screw is removed. You can then remove the disk, and you will be left with a small stud that you might get hold of with some mole grips.
Or failing that, grind the stud flush with your hub, then go in with a small drill..... If that doesn't work then you are into drilling and tapping a new hole for the screw- use the new disk as a guide!
1.) it's a countersunk screw
2.) you are scrapping the brake disk
3.) you have an angle grinder
Grind through the disk in the area around the screw. Go carefully, and grind until the head of the screw is removed. You can then remove the disk, and you will be left with a small stud that you might get hold of with some mole grips.
Or failing that, grind the stud flush with your hub, then go in with a small drill..... If that doesn't work then you are into drilling and tapping a new hole for the screw- use the new disk as a guide!
X8Matt said:
Assuming...
1.) it's a countersunk screw
2.) you are scrapping the brake disk
3.) you have an angle grinder
Grind through the disk in the area around the screw. Go carefully, and grind until the head of the screw is removed. You can then remove the disk, and you will be left with a small stud that you might get hold of with some mole grips.
Or failing that, grind the stud flush with your hub, then go in with a small drill..... If that doesn't work then you are into drilling and tapping a new hole for the screw- use the new disk as a guide!
I have considered this,but it seems a bit too extreme, not sure how much chance i have of doing it without ruining the hub1.) it's a countersunk screw
2.) you are scrapping the brake disk
3.) you have an angle grinder
Grind through the disk in the area around the screw. Go carefully, and grind until the head of the screw is removed. You can then remove the disk, and you will be left with a small stud that you might get hold of with some mole grips.
Or failing that, grind the stud flush with your hub, then go in with a small drill..... If that doesn't work then you are into drilling and tapping a new hole for the screw- use the new disk as a guide!
1) Heat.
2) Penetrating fluid (Plus Gas).
3) Rost Off (freeze spray penetrating fluid on the screw).
4) Hammer a torq bit in the hole.
5) Hammer and Centre punch around the outer edge of the screw flange at a shallow angle in the unscrewing direction (tap the screw around with a hammer and punch).
6) Dremel a slot for large screwdriver blade.
7) Last resort is to drill all the way around the screw flange with a smaller drill bit and lever the disc off (the flange of the screw only needs to come off, you don't need to touch the centre)
I've never had to cut into a disc yet to remove a stubborn retaining screw. I avoid screw extractors because of whats happened to you (happened to me before).
2) Penetrating fluid (Plus Gas).
3) Rost Off (freeze spray penetrating fluid on the screw).
4) Hammer a torq bit in the hole.
5) Hammer and Centre punch around the outer edge of the screw flange at a shallow angle in the unscrewing direction (tap the screw around with a hammer and punch).
6) Dremel a slot for large screwdriver blade.
7) Last resort is to drill all the way around the screw flange with a smaller drill bit and lever the disc off (the flange of the screw only needs to come off, you don't need to touch the centre)
I've never had to cut into a disc yet to remove a stubborn retaining screw. I avoid screw extractors because of whats happened to you (happened to me before).
Buy a better quality screw extractor set, Snap-on do a good one. The bit of the old one which is left in is often (as you now know) brittle, so often just hitting it with a centre punch or nail punch can get it to break into pieces, then you can try again. Some left handed drill bits (part of the aforementioned set) would be good in this instance as you have something which will find you a centre; start with a bigger one, if that doesn't do it then carry on with a smaller one which will take out the threaded part or swap tools at this point for one of the other types.
You could try welding something to it, but it's a method which rarely works in my experience.
http://www.ebay.co.uk/itm/SNAP-ON-35PC-LEFT-HAND-C...
A bit expensive I know, but they are good and it's the reason businesses charge what they do...
This type are good too: https://buy1.snapon.com/catalog/item.asp?item_ID=6...
Other companies (like SykesP make them as well).
You could try welding something to it, but it's a method which rarely works in my experience.
http://www.ebay.co.uk/itm/SNAP-ON-35PC-LEFT-HAND-C...
A bit expensive I know, but they are good and it's the reason businesses charge what they do...
This type are good too: https://buy1.snapon.com/catalog/item.asp?item_ID=6...
Other companies (like SykesP make them as well).
That is a hefty one for a disc retaining screw! Looks like you could hammer an allen key in there and unwind it though 
I've drilled these out in the past and sometimes discovered another thread opposite to the buggered one on the hub where no screw has previously fitted. Difficult to explain but often there is the option for fitting two retaining screws to the disc and only one has been used by the manufacturer so the spare hole/thread should be able to be used if/when you destroy the thread getting that one out. Put a bit of copper grease on the threads before you fit the new screw.
Failing that... Support front of car on axle stands, start car, apply brakes, no screw head
I've drilled these out in the past and sometimes discovered another thread opposite to the buggered one on the hub where no screw has previously fitted. Difficult to explain but often there is the option for fitting two retaining screws to the disc and only one has been used by the manufacturer so the spare hole/thread should be able to be used if/when you destroy the thread getting that one out. Put a bit of copper grease on the threads before you fit the new screw.
Failing that... Support front of car on axle stands, start car, apply brakes, no screw head
Just drill it down to the depth of the hub flange with increasing diameter discs until the disc is free. Grind off anything thats left sticking out until flush with hub face. Fit new disc (no screw required), fit wheel. Job done.
That screw serves no purpose other than to keep the hub/disc wheel stud hole alignment when you (very rarely) take the wheel off. Makes refitting the wheel on those rare occasions a little more tricky but so what?
That screw serves no purpose other than to keep the hub/disc wheel stud hole alignment when you (very rarely) take the wheel off. Makes refitting the wheel on those rare occasions a little more tricky but so what?
russell_ram said:
Just drill it down to the depth of the hub flange with increasing diameter discs until the disc is free. Grind off anything thats left sticking out until flush with hub face. Fit new disc (no screw required), fit wheel. Job done.
That screw serves no purpose other than to keep the hub/disc wheel stud hole alignment when you (very rarely) take the wheel off. Makes refitting the wheel on those rare occasions a little more tricky but so what?
Exactly. Angle grind it off, don't bother with a new one.That screw serves no purpose other than to keep the hub/disc wheel stud hole alignment when you (very rarely) take the wheel off. Makes refitting the wheel on those rare occasions a little more tricky but so what?
Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff