Hi All,

I live in Vancouver. Now there's basically one dealer in lower mainland that is within 50km of my house. I brought my 04' G coupe to the dealer for inspect.

They said my front brakes are due for replacement asap. Then I asked their manager, he said my front brakes has only 20% left. I then took off the tire and use a caliper (digtal display) to check the thickness of my front brake pads. It basically has around 7.0mm left.

I looked at the service manual it says:

Standard
Standard thickness : 11.0 mm (0.433 in)
Repair limit thickness : 2.0 mm (0.079 in)


So 7.0mm is not even close to 2.0mm, why is my dealer saying I have only 20% left? Am I right? or is he right (there's a special way to calculate the thickness???)?

Also, he asked me to replace the rotor as well. I measured my rotor, it's thickness is 22.0mm (which is the minimum thickness according to the Service Manual)

However, there's one thing I found out, the rotor could not have been 24.0mm to start with. It was more like 23.0mm, I know so because I measure the very very edge of the rotor where the brake pad never touch (it measured 23.0mm, and then the area of friction contact kinda cave-in and is thinner ~22.0mm), So am I measuring it wrong? Or is the service manual is wrong?

Here's the service manual spec:
Standard
Standard thickness : 24.0 mm (0.945 in)
Wear limit : 22.0 mm (0.866 in)
Maximum uneven wear
(measured at 8 positions) : 0.015 mm (0.0006 in) or less


Your replies is very much appreciated..

Best Regards,

Brian

 

Don't confuse the pad material thickness with the pad material and backing support plate thickness.

 

Hi Q45,

I measured only the pad material thickness, (just the compound not the metal backing plate). I measured 7.0mm left, but the dealer tech said I need to replace it?? Repair limit thickness : 2.0 mm (0.079 in) means I only need to replace if I have 2.0mm left, right? So I should wait for another 5.0mm wear before replacing it?

Brian

 

The thinner the pad material the less insulation is between caliper piston also the closer the rotor is to the expanded piston. [radiation vs conduction temperature].

Really depends on what the brake fluid temperature is inside the caliper.

The primary reason for setting a minimum is the longevity of caliper piston seal so that the piston doesn't break seal with worn rotors and pads.

Was every pad [inner and outer] measured by you? Maybe tech made a mistake?

 

Hi Q45,

For the front pad, what I did was comparing it to the newly bought Hawks HPS. I measured the new ones, they has 10.0mm compounds on them. I then measure my old pads(on the vehicle, via the access hole on the caliper), they had roughly 7.0mm left.

The Dealer Manager checked my file and told me there's 20% left only. I don't think they would make a mistake, I am just thinking they tell me 20% because they want to make money of me buying replacing my brakes sooner. Therefore I wanted to know if I have measure correctly before I talk to their manager again.

 

I think you should talk to the Service Manager again and tell him about your findings. I was also told the same thing for my Brembo pads. The tech told me when it gets down to 2mm, you need to replace them. I replaced both the fronts and rears at 49,000kms. But I did not physically measure them like you did. So I basically did what they suggested and took their word for it. Just hoping that the dealerships are being honest and telling their customers the truth, instead of trying to gouge them for more money.

BTW, besides buying the Hawk HPS pads, did you end up buying rotors also?

 

Yes, now I need to buy the rotors too. My fronts are 22.0mm left which is the minimum thickness allowed, so dealership won't cut them for me.

Good bye sucky OEM rotors!!

Anyone know what is the best rotor for 04' non-brembo g35 coupe?

I saw people using StopTech, also Power Slot slotted is any good?

Does people prefer drilled or slotted, or slotted-drilled?

I heard drilled is only a eye candy and takes away 20% of the braking surface, hence performance decrease??


Brian

 

There's one thing I found out, the rotor could not have been 24.0mm to start with. It was more like 23.0mm, I know so because I measure the very very edge of the rotor where the brake pad never touch (it measured 23.0mm, and then the area of friction contact kinda cave-in and is thinner ~22.0mm), So am I measuring it wrong? Or is the service manual is wrong?

Here's the service manual spec:
Standard
Standard thickness : 24.0 mm (0.945 in)
Wear limit : 22.0 mm (0.866 in)
Maximum uneven wear
(measured at 8 positions) : 0.015 mm (0.0006 in) or less


Your replies is very much appreciated..

 

Hi GTR_Boy, I asked the dealership tech to return my old pads to me, so here are their measurement. They have around ~5.0mm left on them.

First, the sale person told me my pads are worn out, need replace asap, then I asked their manager, he said 20%, now I measured them, they still have 37.5% left on them??? 3mm /8mm = 37.5% left?

Is my dealership ripping me off?

I hope I am measuring them correct.

ILuvMyG35

 

Well, there's 5mm left if you plan on grinding your steel backing plate against the rotors. You're measureing the thickness of the pad with the backing plate, which is about half the thickness of your pad right now.

As for them needing to be replaced ASAP...They look to me like they still got a few thousand good miles in them. I wouldn't track on these pads, but for street driving they're fine.

 

No.. I measure the backing plate first, then set my reading to 0.0mm (as in the second photo). The measurement is only for the pad compound not including the backing plate.

 

What am I missing one of your photos showned 4.32 mm so 2mm above absolute minimum.

I would have changed them also since I cannot gauge when you might come back and the closer you get to minimum the hotter the pad get and thus increase wear rate vs brand new............wear rate is not linear as you get worn down.

After all thick pads are for your safety.

 

Hi Q45, yeah I guess you are right about the 4.32mm one which has 2.32mm left before minimum. It's really sad all my other 3 pads has like ~5.5mm or more left which is like 37.5% left.

Thanks for telling me the wear rate is not linear, cuz I also thought it is.

 

I wouldn't suggest running any brake pads this far, but if you take a look at the first picture of the brake pads, you'll notice there are strips of metal on the left or right of each pad. Those are wear indicators, and if you really need to replace the brake pads, you'll hear them scrape on your rotors, producing a squeaking sound when you step on the brakes.

 

In my experience, wear indicators tend to squeel whenever you aren't pressing the brakes, and then quiet down when you press the brakes.