Sheered brake disc retaining screw.

[plissken]

After an advisory from the MOT to replace the brake pads and discs I thought it best to get them done as soon as possible as i had the bits all ready and waiting.  On removal of the wheel and the caliper retaining bolts at the back I noticed that the disc was moving freely with the caliper as I was trying to take it off.  In fact once the caliper was removed the disc fell off the hub.  

Both retaining screws (each side of the car) for the discs looked to have sheered off at some point (see attached), leaving what remains of the screw in the hub.  Is this dangerous or given that the discs are held in place by the wheel bolts when the tyre is fitted means that there is no problem?  Has this happened to others?

She is a 63 plate with 99k on the clock.  Full service history from toyota too!

[kisbell]

Typical toyota sheering the retaing screws and fitting the disks.

I would recommend replacing the retaing screws. I know they just hold the disk in place when you remove the wheel nuts but they make it easier to change the wheel at the side of the road at night in the rain. 

[alan333]

It's not really a problem, the fact that the brake calipers and pads are fitted hold the disc in place when changing a tyre etc.

[paulie b]

If discovered the police would probably determine that you are driving a defective vehicle. You'd be up in court and face a hefty fine and points. It's not worth it for your, your passengers and other road users safety. Why take chances with brakes? I'd advise you to get them replaced.

[eygo]

its not something to be concerned about and its certainly not dangerous,

as already said it keeps the brake disc bolt holes lined up with the hub

if it where my car i would drill & tap and replace the screws but thats just me,

when i have changed them in the past its been a M6 countersunk cross head screw

using a 5mm tapping drill.

[Notoyboy]

Count me in for replacing the screws.  Whenever I renew or just remove a disc, I'm always fastidious in cleaning up the mounting face of the back of the disc and the corresponding hub it butts up against, and I smear a little copper grease on the faces to reduce water ingress which might start corrosion.  Refitting the 2 retaining screws minimises risk of the joint being disturbed and a bit of dirt getting in, to cause the disc to run out of true.

[alan333]

9 hours ago, paulie b said:

If discovered the police would probably determine that you are driving a defective vehicle. You'd be up in court and face a hefty fine and points. It's not worth it for your, your passengers and other road users safety. Why take chances with brakes? I'd advise you to get them replaced.

I totally disagree that anyone would find the vehicle defective, and you certainly wouldn't be prosecuted.  Lots of vehicles don't even have these screws to hold the disc in place. As previously stated, the pads hold the disc in place, and the only time the disc could fall off is when the pads and caliper are removed.

[rajivrattna]

I agree with alan333 in this case. Yes I have changed both disc and pads in my Aygo before and I think that you are worrying about something that is a non concern. Once all is bolted (without the retaining screw), it stays put. No one but you know that the retaining screw is not there (and not needed).

[Phil White]

It is not a cause of concern as the screw is not taking any load and simply holds the disc flat against the hub when the wheel is removed. The wheel nuts/bolts hold it flat down so don't worry about that.

I don't know why paulie  b has made that absurd reply either??