how can you tel when your rotors need replacing?

RG.net · Postby **RG.net** » Thu Jun 26, 2008 10:26 pm

hey guys, as the title states, i am not sure on this. i installed ultimates all round and braking was really good but then started to die down, i had the fluid bled but same thing. still plenty of meat on the pads so i am guessing my rotors are on the way out. heres a pic for reference.

the pic is of the rear rotor

Juffa · Postby **Juffa** » Thu Jun 26, 2008 10:55 pm

Engraved on the rotors is their minimum width. Using a feeler gauge you can measure the width. If it is at or below the stated minimum width then they should be replaced. Otherwise I would suggest getting them machined.

J

wun911 · Postby **wun911** » Fri Jun 27, 2008 10:00 am

I think its like 1mm off each side is minimum thickness...
You wouldnt think ultimates eat though a rotor that quickly?

Mr Morlock · Postby **Mr Morlock** » Fri Jun 27, 2008 11:17 am

the brake repairers can easily check and usually they will machine the discs if warranted, check their serviceability and make recommendations.

Steampunk · Postby **Steampunk** » Fri Jun 27, 2008 12:18 pm

wun911 wrote:I think its like 1mm off each side is minimum thickness...
You wouldnt think ultimates eat though a rotor that quickly?

ahhh....no.
Not sure about the rears, but when your front discs get to about 3-4mm left you seriously need replacement.
Reputable shops wont machine your discs at or below 4mm thickness.

Caffeine · Postby **Caffeine** » Fri Jun 27, 2008 1:03 pm

1red5 wrote:
wun911 wrote:I think its like 1mm off each side is minimum thickness...
You wouldnt think ultimates eat though a rotor that quickly?

ahhh....no.
Not sure about the rears, but when your front discs get to about 3-4mm left you seriously need replacement.
Reputable shops wont machine your discs at or below 4mm thickness.

4mm is pretty damned thin for a veltilated disc!

wun911 · Postby **wun911** » Fri Jun 27, 2008 1:32 pm

Ok my poor englash....

Its starts off when its new at 22 mm thick and minimum thickness is 20 mm...

Thus its 1mm off each side of the rotor you understand??

The rear starts off as 10 mm thick and minimum thickness is 8 mm

ie if you want to save weight you can machine them down 1mm on each side.

http://www.dba.com.au/2006/PDF_CATALOGU ... 032008.pdf

(This is for my rotors NB8B)

RG.net · Postby **RG.net** » Fri Jun 27, 2008 7:03 pm

mmm, i was looking at getting slotted rotors sometime soon, got home today and brakes started squeaking, isnt that an indicator of some sort? also could smell them, i think it is time to change them.

Mr Morlock · Postby **Mr Morlock** » Fri Jun 27, 2008 7:55 pm

MX5hevn- squealing and on the nose- yes something is not right. Get them checked- it will not cost you anything for an appraisal. You can ask for recommendation on rotors and whether with your style of driving or use warrants slotted rotors- I imagine they will give you a price as well for that option.