Brake disk retaining screw

[Alpine]

Hello

I have had some noise coming from my brakes, after the pads were stuck and there was a bang as I pulled away. So I took my wheels off today to investigate.

Found that one of the brake disks to my front wheel had no locking screw, it had sheared off. So the disk was able to move around. I assume this is the cause of the noise I was hearing.

I've never worked on brakes before, so not sure whether I can fix this myself or if I should run it round to my mechanic.

I guess I would need to drill out the remains of the screw that has sheared. And then I'd need to buy a new screw, is there a specific one or are they universal? And should there be just one screw to hold the disk in place, or more than 1?

Any guidance welcome!

[ITSv40]

The sheered retaining screw is nothing to do with the bang you heard when the stuck pads freed up. All the screw does is hold the disc in position whilst the wheel retaining bolts are located and torqued up. Five bolts holding the wheel on will make sure the disc doesn't move.

The screws are bog standard metric and I think something like 10mm dia - best to remove the good screw from the other side and measure that to determine the replacement.

I suspect the car has been standing or parked up after washing and the damp pads have stuck to the disc. If so, the bang would be when the pads freed off the disc and now you have a rubbing noise when moving slowly. It will take a little time to polish the disc again and all should be fine. If not the caliper will need to be removed and checked to determine why the pads stuck in the first place.

[Alpine]

oh, ok, I hadn't realised that the wheel bolts would hold it but that makes sense.

There was only one screw holding it, and that is the one that had sheared. So I could spin the disk around

thanks for clarifying, I'll keep driving and hope it goes over time

[XC90Mk1]

Originally Posted by Alpine

oh, ok, I hadn't realised that the wheel bolts would hold it but that makes sense.

There was only one screw holding it, and that is the one that had sheared. So I could spin the disk around

thanks for clarifying, I'll keep driving and hope it goes over time

I think the above answers it perfectly. I am a bit confused as the disc should spin around anyway. As has been said the screw just retains the disc. It’s redundant really so I would not be concerned about it.


I think it would be very very hard to remove the remaining thread.

[400-ascona]

The advantage of having the screw installed is that it stops the disc dropping away from the hub face allowing debris into the mating faces whenever the wheel is removed. Debris between the disc and the hub is far from ideal, so the screw just makes sure they don't part company and allow the risk as well as making it easier to line up the disc, wheel and bolt hole when man handling the big/heavy wheel.

[turboboy]

The screw is a fairly standard size so quite easy to get hold of, either from a Volvo dealer or ebay. As ITSv40 says, have a look at the one on the other side.

As you say you are not familiar with brakes then take it to a garage and any competent mechanic should be able to drill the broken part out.

It is not essential to the operation of the brakes but it can be really inconvenient if missing when you have to remove and replace a wheel (such as changing a wheel when the tyre is punctured, on the side of a country road on dark, wet night) as you struggle to get the wheel bolts back in.

[Dippydog]

Are you sure the pads were stuck and the bang came from the front? The bang could have come from the handbrake shoes releasing after sticking or the shoes delaminating.If you're at all unsure about working on the braking system take it to a garage.

[amazondean]

Originally Posted by Dippydog

Are you sure the pads were stuck and the bang came from the front? The bang could have come from the handbrake shoes releasing after sticking or the shoes delaminating.If you're at all unsure about working on the braking system take it to a garage.

I would say that this is the most likely culprit, as there is some movement of the shoes when they grab, which causes a bang when released sometimes when setting off up the road. The sheared screw probably sheared off last time someone tried to remove it to take the disc off?

[Alpine]

thanks for all of your replies.

I did take it to my mechanic, turns out it was a warped rear disk. Caused from a stuck pad. I run the car weekly apart from a period when it didn't move for 2 weeks. The rears disks are only 3 years old and have done 9k miles.