Pulsing sound when braking

[Shorty33]

Last two sets of rotors that I've purchased for my Omega - brand new; genuine GMH - cost me $80, and $78 respectively, for a set of four.
Picked them both up when I was passing through Melbourne, thanks to Ebay.
How much would I have saved if I had machined my old ones ?

 

[klavins]

oh nice, I thought they would've been way more! Might be worth just getting a new set.

 

[klavins]

Found these on eBay which seem decent; rotors and pads for $290 delivered for a full set

2 Front Disc Brake Rotors Drilled Slotted Holden Commodore VE V6 W Pads ADB2026 | eBay

2 Rear Disc Brake Rotors Drilled Slotted Holden Commodore VE V6 W Pads ADB2027 | eBay

 

[Thumpin]

The longevity of GM Rotor Discs is shocking. I've had issues with them since the VS Model. When I owned my cherished VT, I must have installed 6 different pairs of front rotors using genuine and quality after-market units. All fix the pulsating feel when new but within 15-20,000 K's it was back. The pulsing was most obvious when light braking from higher speeds (100K's or so).
I never got to the bottom of the problem and now it's rared it's ugly head again with the VE!
I fitted the Brembo front Brake package to the VE 20,000K's ago and the pulsing is starting to appear when light braking is applied...? I would consider myself as easy on brakes driver so I'm surprised how easily the disc flatness degrades.
There has been discussions around the inter-face between the disc and the bearing hub face causing runout issues. I have personally looked long and hard at this and apart from some surface rust pitting there was nothing to suggest excessive runout.
I've even checked a pulsing disc with a Dial indicator and didn't get more than 0.003 inch which is good.

So if you have any new ideas, let me know

 

[klavins]

The Brembo package includes the rotors doesn't it? It could possibly be a wheel alignment issue?

I ended up buying a set of RDA Slotted gun metal rotors (RDA7900's) for half price, so $150 for the full set, then I bought some QFM HPX pads for $160 for the set.

 

[Shorty33]

further to my earlier post, concerning rotors, I use Bendix pads - $70 per axle, from Super Cheap.

The mechanic (a mate, who does cashies from his home workshop) who looks after my brakes told me a little story, and Thumpin - this will interest you.
He explained: years ago, rotors were hard, and pads were soft. So we replaced our pads every so often, but rotors outlasted several sets of pads.

But now, improvements in metallurgy, and in the composition of pads (no asbestos) have resulted in larger, but softer rotors, and harder pads. And we now use different brake fluid.
So we will all have to get used to changing our rotors more often than in the good old days.

I did a little research on this, and discovered Porsche recommends that you replace all rotors and pads at the same time - 60,000km is typical - and here's the good bit - it only costs $1,600 ! So, the Commodore seems a lot better value to me !

 

[vc commodore]

It could possibly be a wheel alignment issue?

Nope...

I ended up buying a set of RDA Slotted gun metal rotors (RDA7900's) for half price, so $150 for the full set, then I bought some QFM HPX pads for $160 for the set.

Did it fix the problem?

 

[namboss]

Last two sets of rotors that I've purchased for my Omega - brand new; genuine GMH - cost me $80, and $78 respectively, for a set of four.
Picked them both up when I was passing through Melbourne, thanks to Ebay.
How much would I have saved if I had machined my old ones ?

It usually cost around $50 to machine a rotor, so I'd say about $150-$200 to machine all your rotors depending where you go.
So its always better value to buy a new set of rotors.
Do you install them youself?

 

[Shorty33]

no, I didn't do them myself.
A mate with a well equipped shed behind his house -
replaced the four rotors;
flushed the brake fluid; and
changed the rear pads -
he & I were both in a hurry - I supplied the parts; the jobs took 61 minutes, and I gave him 100 cash.
That was 20,000 km ago - no problems yet.
But I know that I'm lucky to have a mate who doesn't want to rip me off.