Brakes management

[boxerboy]

The pads on my 45K Aurion are almost due for a change.

Why do the discs need to be machined? The discs don't pulsate, and they're smooth enough. I don't do that to my motorcycle discs (which do develop a wavy wear pattern) when I change the pads, in fact, it's rare for anyone I know to do it. However, car mechanics seem to insist it's required.

[SuperDave]

It's to do with the inner section of the rotor getting hotter then the outer section which can cause differential wear (rotor taper). As well as the grooves that can form in the surface from the pads. I've never done it because the pads wear into shape quickly anyway.

[Silver-Aurion]

I've never machined my rotors, I just have a good set of Bendix brakes.

[e240]

I'm surprise at all the replies, I honestly expected everyone to jump on that machining is a must.

If it still smooth, no wobbles, I'd be lazy and just slap the new pads in.

and lazy as I am, I've even slap new pads onto scored rotors, but no issue with braking even on the track.. :-p

[stedyedy]

The pads on my 45K Aurion are almost due for a change.

Why do the discs need to be machined? The discs don't pulsate, and they're smooth enough. I don't do that to my motorcycle discs (which do develop a wavy wear pattern) when I change the pads, in fact, it's rare for anyone I know to do it. However, car mechanics seem to insist it's required.

how much would they charge you for the machining?

Edited July 21, 2010 by stedyedy

[450HP/tonne]

how much would they charge you for the machining?

I have in the past had some brake shudder issues (in my pre-Toyota days) and it cost $220 front and $120 rear for rotor machining (at 90,000km).

Unless you have a complaint, I wouldn't recommend it, as it uses up rotor thickness, which means you'll need to buy new ones sooner (or have other possible issues).

At a guess for an Aurion, you would be up for probably over $500 for a set of new front rotors and over $250 for rears.

Which reminds me, I have a full vehicle set of pads and discs (taken from a new Aurion which was never registered or driven) that I could either sell, or keep for when my Aurion needs them (but currently only at 15,000km) ... probably will keep them and sell them later if I no longer have an Aurion.

[e240]

I have in the past had some brake shudder issues (in my pre-Toyota days) and it cost $220 front and $120 rear for rotor machining (at 90,000km).

...

At a guess for an Aurion, you would be up for probably over $500 for a set of new front rotors and over $250 for rears.

In my case,I weighed up the cost of machining and decided to just get RDA Rotors.What Toyota quoted me to Machine, with just a little bit more, I got myself a set of slotted RDA rotors and pads.

I think I posted on this sometime back...let me go find that post

[e240]

I have in the past had some brake shudder issues (in my pre-Toyota days) and it cost $220 front and $120 rear for rotor machining (at 90,000km).

...

At a guess for an Aurion, you would be up for probably over $500 for a set of new front rotors and over $250 for rears.

In my case,I weighed up the cost of machining and decided to just get RDA Rotors.What Toyota quoted me to Machine, with just a little bit more, I got myself a set of slotted RDA rotors and pads.

I think I posted on this sometime back...let me go find that post

Edited July 22, 2010 by e240

[matt36415]

I think machining is another way of extracting money form customers - If your pads have not gotten down to the metal backing then machining is not normally needed - sometimes they will machine them and then ring you and say they are below minimum thickness so you have to have new discs - and you are stuck buying over priced Toyota ones then.

Get a manual - do the job yourself

[SuperDave]

Don't really need a manual for doing brakes. The only thing to point out is if it is very hard to push the piston back, it may very well be a screw type and continuing to attempt to push it back will damage it. I have only really heard of Honda doing this though.

[e240]

Don't really need a manual for doing brakes. The only thing to point out is if it is very hard to push the piston back, it may very well be a screw type and continuing to attempt to push it back will damage it. I have only really heard of Honda doing this though.

Just use an appropriately sized g-clamp and you can easily get the pistons pushed in (for single piston)

For multiple pistons, use a wooden block and ensure all the pistons are pushed in at the same time or, to push them in individually, just loosen the bleed screw (watch that fluid!)

Screw in type caliper, as found on Honda's, are only on the rears and has to do with the handbrake mechanism. It prevents the pistons from pushing back in when the handbrake it engaged.

[GSV40R]

if a dealer has an on car machiner (lathe) it should be cheap. $40 - 60 a pair. if they have to remove the rotors and sublet them then it becomes dearer.

the is a minimum spec on rotor runout and thickness (obviously) so if there aren't any deep grooves on lips on the edge of the rotor then they normally won't need machining. But in a dealers deffence if you were charged for labour , pads and machining the job is done and done right the first time. if you chose not to have the rotors machined and your brakes became very noisey afterwards and then they needed machining i bet you as the owner would not be prepared to pay for another lot of labour and the machining on top of that again.

it is a catch 22 situation. as far as replacement the dealer where i work will give the option for genuine or non genuine replacement rotors where needed as there can be a huge difference in price, but seeing the aurion and camry are ozzie built the rotors probably come from the same factory and the non gen units. as far as a japanese vehicle goes the rotor quality is better but sometime 3 times the price.. there is a reason that the corolla built in south africa stopped coming into australia , front pads and rotors at 25 -30k christ thats worse than a daewoo lanos or a holden astra (fr rotors made from cheese)

[KLT3912]

how much would they charge you for the machining?

I have in the past had some brake shudder issues (in my pre-Toyota days) and it cost $220 front and $120 rear for rotor machining (at 90,000km).

Unless you have a complaint, I wouldn't recommend it, as it uses up rotor thickness, which means you'll need to buy new ones sooner (or have other possible issues).

At a guess for an Aurion, you would be up for probably over $500 for a set of new front rotors and over $250 for rears.

Which reminds me, I have a full vehicle set of pads and discs (taken from a new Aurion which was never registered or driven) that I could either sell, or keep for when my Aurion needs them (but currently only at 15,000km) ... probably will keep them and sell them later if I no longer have an Aurion.

Ebay sells the rotor in a pair for less than AU$300.00 + shipping from NSW.

URGENT: Do u know the minimum thickness of Aurion Front & rear rotors? Want to know 'cause my Aurion is vibrating when braking from 110 Km/hour or at higher speeds.

Thanks: leck@netspace.net.au

[KLT3912]

It's to do with the inner section of the rotor getting hotter then the outer section which can cause differential wear (rotor taper). As well as the grooves that can form in the surface from the pads. I've never done it because the pads wear into shape quickly anyway.

URGENT please: Do u know the minimum thickness of Aurion Front & rear rotors? Want to know 'cause my Aurion is vibrating when braking from 110 Km/hour or at higher speeds.

Thank you: leck@netspace.net.au

[SuperDave]

Sometimes it is moulded into the rotor somewhere. But a quick search on the DBA website says 25mm is minimum.

[julian040859]

Here is an exert from..........Camry Stuff...... Gen6......Brake Manual Page BR 50

It confirms what superdave has posted for FRONT Disc Brakes

2. INSPECT DISC THICKNESS

(a) Using a micrometer, measure the disc thickness.

Standard thickness:

28.0 mm (1.102 in.)

Minimum thickness :

25.0 mm ( 0.983 in.)

If the disc thickness is less than the minimum,

replace the front disc.

Edited August 19, 2010 by julian040859

[ZR6_AurionT]

It is best to machine your rotors when pads are replaced. If not machined, may cause glazed rotors and it will start to make squeaky sounds even with the new pads.

Obviously, machining rotor isn't just a rip-off.

[DJKOR]

It is best to machine your rotors when pads are replaced. If not machined, may cause glazed rotors and it will start to make squeaky sounds even with the new pads.

Obviously, machining rotor isn't just a rip-off.

I would have to disagree with that statement. I have had rotors that have gone though a few consecutive pad changes without a single machining. If anything, machining the rotors would create a higher chance of your rotors glazing as there is now less material on them to be able to handle heat.

[SuperDave]

Machining the rotors will require them to be bed in again, which will increase your chances of uneven brake pad material deposits in the rotor surface. I've never had my brake rotors machined, been through maybe 10 sets of pads and not one case of warped rotors. Glazing isn't a problem as it wears away in 50-100km depending on how often you use the brakes; just keep in mind your braking distances increase when they have glazed; once the glazing is gone they come back fine.

[stedyedy]

Been experiencing some wheel shake when breaking from 100KM+, gave the mechanic a call to see if it was worth machining them or getting new ones, he said it would only cost about $10 a rotor to machine them

[boxerboy]

Squeaky brakes on my bike is usually glazing. It happens after a few months of commuting.

One hard ride thru some mountain twisties, with heavy braking fixes the glazing, and the squeak is gone.

I never machine those discs, ever, and I figure the same technique in the car will fix any glazing.

I've been told by a m/c disc manufacturer that heat will warp discs. He describes the situation where after some spirited riding/braking one comes to a stop. The pads are held to the disc and a hot spot develops. He suggested that it was best to brake, stop but roll ever so slowly to spread the heat away from the one spot.

That advice was many years ago. No warped discs since.

[DJKOR]

He suggested that it was best to brake, stop but roll ever so slowly to spread the heat away from the one spot.

That advice was many years ago. No warped discs since.

This is what I did ever since I changed the rotors on my last Aurion. Never got a vibration issue ever again. Could also be with the combination of the better rotors, but I still did it either way. Last thing I wanted to do was warp them like the last. I also try to take my foot off the brakes whenever possible like when I am on a level surface.

[e240]

I think there's some incorrect information going on here...

Glazing does not simply go away with heavy breaking - In most cases glazing occurs when the resin that hold the pad harden up due to improper running in leaving very hard deposits on the rotors and pads - the only way to get rid of this is by machining both the pads and rotors.

If you find heavy braking helps, then chances are your pads were never glazed in the first place, more likely not bedded in properly.

Speaking brakes does not mean your rotors and pads are glazed, there could be other reasons for this.

There will be situations where you need to machine your rotors, especially if they're glazed, warped or badly grooved.

Simply changing new pads may not warrant machining unless the above conditions are present.

[boxerboy]

You may be right, and I did qualify by saying that this was on my bike.

It's also commonly reported by other users, usual pads that are involved are ebc brand, so I'm not the only one. I guess they all might be wrong? Usual fix is to do figure of 8's on sand paper, then reinstall. It does work, for a while.

But remember, this is a bike, not the car.

[julian040859]

If you do not get a shudder or pulsating through the brake pedal and it is just a squeak from glazed rotors, why not try buffing them with a medium grit wet and dry sand paper or wire brush. It has worked for me and saved machining the disc !

Edited August 31, 2010 by julian040859