S40 (New) Brakes : Advice please.

[PNM]

I've just had my car back from a service, and the garage (main dealer) has advised that due to the rust on the outside of my rear disks, they need replacing.

I was a little surprised by this as
1) It has not long passed an MOT (local indie) with no brake related advisories
2) The rust is only present on the part that the pads don't sweep
3) I've had a quick look around the supermarket car park and it seems that most cars have rust on the edge of their disks to some degree.
4) It only appears to be surface rust - the edges of the disk are not flaking away.

What are peoples thoughts? If it's a safety issue, I will replace them ASAP, but equally, don't want to be wasting time and money on work if the garage is just trying to create a bit of extra revenue.

TIA

[Clan]

Originally Posted by PNM

I've just had my car back from a service, and the garage (main dealer) has advised that due to the rust on the outside of my rear disks, they need replacing.

I was a little surprised by this as
1) It has not long passed an MOT (local indie) with no brake related advisories
2) The rust is only present on the part that the pads don't sweep
3) I've had a quick look around the supermarket car park and it seems that most cars have rust on the edge of their disks to some degree.
4) It only appears to be surface rust - the edges of the disk are not flaking away.

What are peoples thoughts? If it's a safety issue, I will replace them ASAP, but equally, don't want to be wasting time and money on work if the garage is just trying to create a bit of extra revenue.

TIA

Only 75% of the swept area is useful the rest is heavy rusty they were right to advise you , they would be incompetent if they let this go out without telling you ..Their service life is over and has been for some time , remember your parking brake depends on these too. It is a good time for some new discs and pads , The pads are probably seized which is what causes this in the first place ..

[T5R92011]

Agree discs AND pads should be replaced here. Looks like the original discs to me.

You can obviously still drive around, but your rear brakes won't be as effective as they should be, and I wouldn't be surprised if you were getting vibration under braking due to that rough patch of rust.

Would expect that to have been an advisory, though I'm not an MOT tester.

[XC90Mk1]

Originally Posted by PNM

I've just had my car back from a service, and the garage (main dealer) has advised that due to the rust on the outside of my rear disks, they need replacing.

I was a little surprised by this as
1) It has not long passed an MOT (local indie) with no brake related advisories
2) The rust is only present on the part that the pads don't sweep
3) I've had a quick look around the supermarket car park and it seems that most cars have rust on the edge of their disks to some degree.
4) It only appears to be surface rust - the edges of the disk are not flaking away.

What are peoples thoughts? If it's a safety issue, I will replace them ASAP, but equally, don't want to be wasting time and money on work if the garage is just trying to create a bit of extra revenue.

TIA

They are absolutely hanging!!!

They will be below bottom limits on thickness and no good at all. If you get to a modest speed and apply the brakes increasingly hard I would expect you to feel pulsing through the pedal.

Change immediately.

[PNM]

Thanks guys.

I'll get them changed ASAP.

[LizardOfBodom]

Guys, sorry but this all seem a bit over the top - rust on the edges/tip of the disc? Its totally normal for the parts not in contact with pads to rust, unless you have zinc coated discs.... I agree that in this case it looks like pads are unevenly worn and replacing discs would be good practice to not mess up new sets of pads, but it is NOT a brake disc that qualifies for MOT fail or immediate replacement cause "ohMyGodIamgonnaDie"...

[XC90Mk1]

Originally Posted by LizardOfBodom

Guys, sorry but this all seem a bit over the top - rust on the edges/tip of the disc? Its totally normal for the parts not in contact with pads to rust, unless you have zinc coated discs.... I agree that in this case it looks like pads are unevenly worn and replacing discs would be good practice to not mess up new sets of pads, but it is NOT a brake disc that qualifies for MOT fail or immediate replacement cause "ohMyGodIamgonnaDie"...

What are you on? Rust around the sides of the disc yes. There is a 1/2 inch band of rust on the face!

They are appaling!

[LizardOfBodom]

Originally Posted by XC90Mk1

What are you on? Rust around the sides of the disc yes. There is a 1/2 inch band of rust on the face!

They are appaling!

Im currently on the chair, thanks, and you?
ever wondered WHY it has rust on the face? Its caused by pads not being in contact with disc, and why is that? either piston problems in caliper, making pads unevenly touching or pads are worn out badly. Rust wouldnt be on it if pads were properly alligned/pressed but in most cases its just surface rust. This pic is an indication of an ongoing issue (caliper/improperly bedded pads) that require investigating but not just "lets replace disc&pads and fingers crossed it will be better" as if pistons are seized or user doesnt do proper brake bedding, it may end up in the same situation in a while.
YES, I would replace discs & pads in this case mysef but only to not destroy new pads by uneven wearing. But it is not worn/cracked damaged disc you are looking at I would clean up the rust first to see REAL condition of the part rather than spreading terror&fear around.
Sometimes understanding the cause of issue is more important than just throwing parts randomly into the equasion and hoping it will help...