Brake rotor wear - Question

[break]

Hey All,

I had the good 'ol brake pad wear light come on the other day and had a check of the pads/disks. The pads still had a bit left in them, but for safety sake I decided to order a new set.

The rear rotors are evenly worn down, and have minimal wear across the entire rotor. So I decided to keep them and I will just get them machined prior to fitting the new pads.

However, the front rotors, particularly the front left is very unevenly worn.

On one edge of the disk it's still a good ~1cm thick, where the opposite side of the face of the disk is ~4mm thick. I'm completely baffled how a disk wears at an angle across the face of the disk. I have no brake fade, no vibrations under heavy braking, and no squealing from the front disks.

Anyone got any idea what might of caused this sort of wear? I've seen uneven pad wear cause other patterns on the rotor face, but never this type of wear.

Oh, and side note. Can anyone suggest a quality brake fluid for the Polos? It's my understanding it's a bad idea to mix brands of brake fluid, but I have no idea what the Polo's run stock.

[noone]

??? That sounds pretty scary.

My understanding of uneven wear is that it would not be visible. the actual wear of the disc is only a few mm's, so having one area of a disk heavily worn is very strange... When I had my discs machined, you could not see the uneven wear (was originally told by a few people warped, but just uneven wear likely to do with ABS braking at the track).

Any chance of a photo?

Martini brake fluid is a preferred choice, I got mine from ebay seller in Tassie (need 2 bottles) or one of the Mechanics on here can probably help you out.

The Pad indicator will come up well before you need to change the pads (thats kind of the point of the indicator), I'd be much more concerned about your rotors than pads with 1/3 bite left...

[break]

<snip>

Yeah, I'll organize a photo when I can to give an example.

Cheers on the brake fluid recommendation.

But yeah, front pads still have ~5mm, where the rears have ~3mm. Still enough to not panic yet... but the state of the rotor is quite worrying.

I can't imagine what might have warped the rotor or caused this wear. While I am a mountain run junkie, I always give them a good warm-up and cool-down before and after, and even with my punishment they've never given me any loss of pedal feel or braking ability during any of those runs.

[noone]

I have a set sitting here doing nothing, but they are damn heavy, so freight would make getting them to you expensive.

[break]

I have a set sitting here doing nothing, but they are damn heavy, so freight would make getting them to you expensive.

Cheers for the offer, but I've already ordered a set of front rotors so I'll be right to get all this fixed up nice and quickly.

[seangti]

how many km's you done?

Another post yesterday had a bloke wearing out the rotors in 45kms. I'd have thought that was a bit premature unless it's driven hard regularly. Alfa romeo's are a 60,000km life for pads and discs, wouldn't have thought ours would be less.

[break]

how many km's you done?

Another post yesterday had a bloke wearing out the rotors in 45kms. I'd have thought that was a bit premature unless it's driven hard regularly. Alfa romeo's are a 60,000km life for pads and discs, wouldn't have thought ours would be less.

I've just hit 50k on the clock. I've had the car for 13k of that, and while the previous owner was an older lady I've definitely given the brakes a workout as I like my mountain driving.

[gslrallysport]

Can anyone suggest a quality brake fluid for the Polos?

If you're just after a standard street fluid, then any $7 bottle of Dot 4 from your local servo will be fine, regardless of brand. Dot 3 and 4 are formulation standards, not performance standards, so all Dot 4 fluid is virtually identical.

If you're after a performance fluid the stuff that we use and recommend is the TRW GP600 Dot 4 Racing Brake Fluid. Good for 312 degrees (or exactly the same as Motul RBF600) and made by the same manufacturer that makes the majority of the braking components for the Audi/VW group (TRW). $65 for a 1L bottle.

[4wheels]

Uneven disc wear

I've seen that sort of uneven wear on my son's Bora V6. Turned out to be a loose axle nut (LHS front) allowing the outer edge of the disc to contact the calipers, probably just on right turns. So worth checking the axle nut torque.

Brian
2007 Trakkadu

[gtimonkey]

rotor wear

I have found that my brake pads/rotors have not lasted particularly long (a little less than break's).

This was the reason for my decision to upgrade to 312mm s3/tt combo, I figured that while I was replacing I should go for something bigger.

Apparently good brake fluid makes a big difference.

Personally I think the brakes and handling are the biggest limitations of the pog - even with stock power

[vwguy86]

dry/unlubricated caliper slides will cause irregular wear of pad's and rotor's ensure when you put the new pad's and rotors on you lubricate them with special hih melting point caliper slide grease

[gslrallysport]

dry/unlubricated caliper slides will cause irregular wear of pad's and rotor's ensure when you put the new pad's and rotors on you lubricate them with special hih melting point caliper slide grease

Quoted for truth!!!

[break]

Another Q,

I've been told by a mechanic that Euro rotors shouldn't be machined. Anyone able to comment on that, as I can't see why not.

[Jmac]

Just for the record it was me that suggested that the rotors not be machined and seeing as im on display ill happily comment. If you have a lip or bevel im sure you will be close to the minimum thickness. There is 3mm between new and old, if your rotors are already showing signs of lipping then you will take out the hardening of the rotor and /or get near the minimum, in which case if you do the new pads will out do the machined rotor, im happy to take critisism here too, i wouldnt machine them and on the same token i wouldnt just replace them willy nilly either.
Jmac

[break]

See the PM Jim, I posted that up this morning prior to calling you in the afternoon for the quote and clarification.

Thanks for the clarification on the phone, much appreciated mate!

Edit: Your inbox is full so can't reply to your PM mate, can you let me know when you've cleared it up.