Disc wear and WoF.

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rob_man, Sep 7, 9:07pm
Is it normal practice for a WoF inspector to measure brake disc wear even if the brakes appear to be working fine!
cuda.340, Sep 7, 9:11pm
x1
if you're going to a competant WOF man sure. if you went to the slackass mechanic our company use he only checks tread depth & indicators n lights. doesn't even test the brakes.
kazbanz, Sep 7, 9:13pm
mmmm-- nahh yea nahh yea um maybee.
In most cases they use the eyecrometer.-mehh it looks unworn or a tiny bit worn.
When they suspect the disks are very worn then its time for closer examination
PS some car yard has been trying to call you .
mrfxit, Sep 7, 9:17pm
Bit tricky to get the measurements right considering the vast number of different vehicles & size of brake rotors fitted + variations in models.

Nothing wrong with an "eyecrometer" as long as it's used correctly
kazbanz, Sep 7, 9:20pm
comeon bro you know better than that. :-)
When its blatant it doesn't take a rocket scientist.
Next step wuld be whip the wheels off and check the minimum thickness stamped on the disks.
mugenb20b, Sep 7, 9:30pm
No. WoF check is based on a visual inspection.
franc123, Sep 7, 9:34pm
Yes it is, its a VIRM requirement that they fail if they are found to be undersize, but in practice the inspector won't always do a measure, or order a measure if it needs the wheels taken off, unless there are obvious signs of bad wear, ie large ridges or thickness variation on the surface where the pads run.
mrfxit, Sep 7, 9:36pm
LOL well yea. but WE know how to work an eyecrometer correctly.
A few minor groves are fine & even a 'bit" of a lip can be fine, on a joe blogs vehicle, particularly on the older vehicles, but imagine the mess resulting in the vtnz sticking to the rule book for brake rotor health
mrfxit, Sep 7, 9:46pm
It's not up to a vtnz inspector to "measure" anything, it's a VISUAL inspection only.
IF. a fault is suspected, THEN they can request a professional inspection assessment is done & the resulting paper work goes back for the vtnz inspector to view & act on accordingly.
About the only things that a wof inspector can "measure" is.

Tire tread depth
Brake performance
Exhaust noise levels
Suspension/chassis to ground height.
Rust hole size (if not clearly under or over legal size)

The rest is eyecrometer work
r15, Sep 7, 9:50pm
not trying to start a shitfight,

but i notice a lot of people coming on this forum of late having a bit of a moan about WOF inspections calling them out on things that ARE wrong with their vehicle.

WOF requirement or not, if your vehicle has worn discs past their service limit or insert other issue here, then it's not going to perform as intended, and therefore likely be unsafe.a cracked disc can make a hell of a mess and kill people,

is it really that hard to keep our vehicles maintained nz!
mrfxit, Sep 7, 9:53pm
Thats why the inspectors need good eyecrometers, so they can access correctly if Professional repair advice/work is needed.
bellky, Sep 7, 9:54pm
VTNZ didn't measure my exhaust noise - they just said it was too loud. I think you'll find it's a 'subjective noise level test'. If the Inspector(s) think the noise level is around or above 92dB then the exhaust needs to be quietened or certed.
kazbanz, Sep 7, 10:34pm
Gee wiillikers bro you are in a bad mood today.
Think it through mon.
Its just good customer service
VTNZ etc dont actually WANT to fail your cars WOF despite the opinions expressed here.
So Yea -you are right they should refer to a specialist. But heck in the interest of customer service they reach up with a micrometer and measure the disk thickness for you.
Most times the feedback is. Look your disks are borderline . Take em to a mechanic soon and get new ones fitted.
If its odvious then again rather than sending em away for a check and have the checker say yep undersize -then off to your mechanic for new disks . Ohhh ya get my point.
Even more pertinant when the wof guy is also your mechanic.
I bet you a lot of moolah he values you as a customer but values his WOF licence a lot more.
So he sees borderline/undersize disks.-as the wof tester it ends there.
As YOUR mechanic he then rips the wheels off for a proper measure.
Darn car is already on the hoist.-YUP SORRYdisks need a skim/need replacingor hey I did a measure and your disks are .5mm from minimum thickness-theyll need replacing soon.
Just plain ol fashioned customer service or perhaps better still common sense
mrfxit, Sep 7, 11:01pm
LOL Kaz, sorry, not meaning to come across as grumpy.
Just getting tired of ppl taking things too far in either direction.
You know that I try to stick to the facts combined with common sense.

Sorry guys, if I sound like a bear with a sore tooth . Well I am <.
1 tooth out + 1st stage of 3 stages to get a root canal done.
Discounted from $1400 just for the repair to $1022 including the tooth out.(that was spose to be $140 on it's own)
LOL see . just goes to show that us older mechanics can still get a discount where it hurts. ;-)

LOL .ouch.LOL. ouch . (it only laughs when I hurt!)
mrfxit, Sep 7, 11:07pm
Story of being pedantic.> >>>

Car got failed for surface rust on chassis rails.(there were bits of grass on some rail joints)
Took it home, sanded it, painted it with underseal, took it back & got my wof.
(great)

Next wof, same shop, different inspector
Got quized at length about why there was fairly recent underseal on the rails, (there were bits of grass on some rail joints)
Sorted easily when the boss came over, (he's got a good set of eyecrometers) & could see I had been in the paddock a few times.
unbeatabull, Sep 7, 11:10pm
End of the day, the VIRM is open to interpretation by each individual inspector. The VIRM states if rotors etc are under thickness, it can be failed. It is up to the inspector as to whether they interpret that as just a quick visual check or actually going further and measuring them to make sure - assuming they can be easily measured without removing the wheels.

Same applies to most issues brought up like this.
mrfxit, Sep 7, 11:15pm
Agreed,
Only hassle is the inspector not having the correct spec's for that vehicle, issues a fail, customer spends $$ getting checked to find it pass's factory spec's anyway.
mrfxit, Sep 7, 11:16pm
Really tho, if it looks badly worn, then it probably is.
ladatrouble, Sep 8, 12:19am
Most cars have dust shields and you can't measure the rotors. However Commodores, Falcons and motorcycles don't - if you can fit the micrometer in there you can use it. Just like a tread depth gauge, it's a tool you can use. You can't pull a wheel to check - but if the AVI is also doing a service at the same time.fair game.
unbeatabull, Sep 8, 12:44am
I've came across very very few cars I haven't been able to fit a pair of vernier calipers in between the rotor and the dust shield to measure the thickness.
ladatrouble, Sep 8, 3:40am
The vernier isn't going to give a minimum if there is a lip on the rotor, but if that outer edge is below min then go for it.
unbeatabull, Sep 8, 6:16am
Yes it does. Most Automotive Verniers you buy will have a bit ground out of them for the lip to sit into so it doesn't affect the reading. Or in my case when I just got a cheap set, I just grinded a little bit out on both sides so they slip over the lip fine.
rob_man, Sep 8, 6:22am
Sorry, been away all day. I'm talking about a mechanic being able to seek out a problem because things are a bit quiet.
Not wanting to get into the morality or politics of disc thickness.
unbeatabull, Sep 8, 6:27am
If there is a problem then its fair enough. Its when they fail things that don't exist or not actually part of the VIRM/WOF that it can be like that.
rob_man, Sep 8, 8:36am
I was in Hamilton all day, I'll try and figure out which one it was and call in tomorrow.