When is it a good time to replace.

When they are worn out to the extent that you need new brakes ?

I think they require replacing when they are 1mm below the width of a new disc.

You can tell how much under the discs are as a small wear lip will be apparent on the rotor.

the MINIMUM thickness of the disc is stamped into the hub of the disc - all depends why you are asking- do u mean "how do i know if they are worn" ??

when the squel shims start to make that deadful noise

thats the pads!

Wanted to know because my Pads will need changing soon. But Discs are usually damaged by worn pads. There is no sound of any damage or wear and tear although still very smooth there are however visible circular markings on the shiny steel outer surface of the discs. So I was a little concerned. Just the front ones.

Just had new discs and pads fitted on the front. Also had the calipers serviced with new rings and seals. 5 years so not bad.

If theres a big lip around the outside edge of the discs then the discs are showing signs of wear,but by the sounds of it there fine,the circular marks on the discs is because like you say the pads are low,the pads are heating up quicker and holding more heat and transferring the heat to the discs.You may also find the brake pedal is getting softer if you brake hard.

Cheers chips.

Thanks, So are you saying ideally the pads should be changed now rather than the marks getting worse

Another thing, whats the best place to get set of pads and front discs; from lexus or some place else. Clearly I am having a brake attack but cant afford to compromise on brakes for much longer. All those useless trips should have stayed at home to conserve fuel also. (Ha!)

If your doing alot of driving and at motorway speeds id change them now,if your just driving the car local,to the shops etc they will be ok for a while.

Yes good advice. Thanks.

Prices from lexus are as follows.

Front Pads (set) £58.24 +vat (part number 04465-30320)
Rear Pads (set) £34.44 +vat (part number 04466-30190)

Front Discs (each) £74.22 +vat

Cheaper non lexus parts are also available but I have been advised not to go for anything too budget as they could ware out much quicker.

The part numbers if specified at a Toyata garage may also be available there. Hope this helps people with brake change ideas.

My brake & money worries continue. Want to know if replacing only the front pads is ok given that the front discs may be slightly worn also. All advice greatly appreciated.

Get the disc thickness measured. Minimum is 30mm, they are 32mm new. If they are 30.5 or less I would change them otherwise they would need changing before the pads need doing again.

You could also get the runout checked. That should be less than 0.05mm

Cheers Colin & The runout not sure what this is ?

Some relevant links I found

http://www.popularmechanics.com/automotive...html?page=2&c=y

http://www.apracing.com/roadcar/brakekit/stdrive.htm

I Had the Discs measured. Both front are less then the minimum. Readings were 28mm +/-. Although the braking is still fine and it was time to renew the pads clearly its both Pad & Disc change time now sooner than later; maybe someone would like to add now urgent.

If they are below the minimum. you are putting your own and other people's lives at risk - get them changed tomorrow!

Yes ASAP. Firstly I found out very late but just glad that all is OK and all was OK. I am simply astonished and impressed that the braking is still very good but after the change it is likely to feel very different also. So I will find out how soft and spongy it may really have become.

Can people confirm that the front discs for 1998 Mk2 GS300SE are the following spec and in particular do they also have the 5 extra vented mountings on the original lexus discs. Cant seem to remember now when wheels were off last time.
Thinking of ordering these. If anyone knows any others grateful for info.

http://www.speedways.co.uk/shop/en-gb/dsk316.htm

Can someone also list some good Disc manufacturers/brands.

Brembo
Magnum
DBC

Thank you Mr. Morse.
But my local autos Garage Jap Specialist is offering ADL Discs and Pads.
I can only take satisfaction in the fact that after running with worn discs and nearly worn out pads that I get both items changed for future use.
Although I am not an expert to know if such poor condition & usage affects other brake components. Hopefully not.
The ADL deal on the Discs is £117.40 + vat (pair) a considerable saving on the Discs from Lexus. Any ADL people out there please let me know.

Calling Aido!!!!!!

What did you recently have fitted to yours dude?

I had Pagid fronts and ADL rears fitted about a month ago

Have to admit I'm not 100% happy with the braking, took it to Lexus for them to bleed the system but it's still not as sharp as it used to be, I am happy however with the amount of brake dust put out on the rears, the ADL disk & Mintex combo is great for that, the fronts however are eating brake dust and it's everywhere after a few days

Seeing as the rear brakes don't do much of the work I can't honestly say how good they are at the front as the Pagid's on mine are doing most of the work!

Had my brakes (Discs & Pads) replaced today. The pads were very bad on drivers side nearly completely worn. The passenger side were also badly worn. The braking is now much firmer. Considerably more. Usual recommendation 200 miles for the pads to settle in. But one question on non-genuine (non lexus parts). The ADL disc was not an exact replica match. Although fully vented (although venting design different) but on the inner side there were no additional vents like on the ones replaced (similar to jet engine turbofans). I realize I have budgeted on costs but could this be a problem in any way.

My news front discs there seems to be lots of rusty copper deposit on the disc surface is this normal. Are these caused by water droplets.

its just rust caused by water - brake a few timaes then have a look - it is nothing to worry about, all discs do it.

ok fine thanks. Probably more so since driving less lately.

Hi guys.

Was just reading this older thread and was wondering...As my front pads are low, I've just bought a set of front pads. Cost £60 inc VAT. But I was wondering what the new and minimum thicknesses are for the front discs. Mine are solid all round, I know that the 2004 models got ventillated fronts. I may aswell get those checked too while I'm doing the pads.

Thanks in advance

all years had ventilated discs even in 1999. From what I remember new thickness is 32mm wear limit is a thickness of 30mm.

Really ?! Mine came with solid fronts. The dealer even had to check the VIN cos he aid there were 2 slightly different types of front pads for the IS200. I was assuming that was due to the difference between non/ventilated...Hmmm now I really wanna check em hehe. If they need changing then vents are gonna have to be done all round

Something dodgy going on.... definitely should have Ventilated discs on the front!

Is this a Lexus dealer?

I don't know if it's possible but did the last owner put rear discs on the front by mistake?..... has to be a mistake as rear ones cost more usually .

Interesting...Unless they had to change the original vent fronts but couldnt be bothered to pay the extra and got solids fitted. - My braking is excellent though. I might have to look further into this ...

Did you find out what was the story with those front "solid"discs yet.....

Out of interest how thick were they...... just thinking if they were rear disc thickness your pistons must have been way out to even make contact......