Dbltime

I had a big red brake set installed one year ago. They have 6,000 track miles and maybe 3,000 street. The front rotors have cracks coming out of the cooling holes on the front rotors all the way around. Should these be replaced sooner rather than later or will they just eat pads quicker?

Flying Finn

I think shop manual (or owner's manual) says that if there are small cracks here and there, it's ok, but when they are bigger, you should change.

Don't have any experience though.

E. J. - 993 Alumni

Bill,

The concensus is that if the cracks coming from the holes are touching - in other words go from hole to hole - of the cracks from the outermost holes go all the way to the edge of the rotor, then you should replace them. If not, then wait til they do.

E. J.

Dbltime

Sounds good to me. The cracks are only 3mm on each side of each hole. They should have a DE day, 30 minute sprint and 90 minute enduro left in them. Then its back to the shop anyway.

Rocket

Bill......you might also start to experience some warping and deterioration in stopping power when they start to out live their usefulness, and in my case by then the cracking looked really quite worrying.

Strangely though, when the rotors were changed the inside faces were hardly cracked at all (that might be the brake cooling kit running the insides cooler).

In my experience Pagid Orange pads accelerates cracking quite considerably too, compared to the standard pad.

Rocket

George from MD

EJ is right. I will add that certain pads seem to promote cracking more than others. Cool Carbons and PFs (no matter which compound) seemed to promote the tracking. I've been using Hawk blues over the past year and had absolutely no cracking- the rotors finally just wore out.

Dbltime

Interesting... I am running Pagid orange.

Greg Fishman

[quote]Originally posted by George from MD:
<strong>EJ is right. I will add that certain pads seem to promote cracking more than others. Cool Carbons and PFs (no matter which compound) seemed to promote the tracking. I've been using Hawk blues over the past year and had absolutely no cracking- the rotors finally just wore out.</strong><hr></blockquote>


Must be me because I get the cracks with Hawk Blues also. As stated earlier no problems with small cracks, just keep a watch on them.
Greg

Ben in Plano, TX

I was told by a p-car technician that the spec is 10mm. Less don't worry, more replace.

Ben

George from MD

Greg- hard to explain- I dunno. But let me also ask where is everyone getting their rotors? I'm going to Vertex but painting the hubs with high heat paint and baking in the oven on the clean setting for an hour which may help with the cracking- I wasn't doing this before.

Ray Calvo

From Greg from MD
[quote]I'm going to Vertex<hr></blockquote>

I wouldn't give Vertex the time of day!!! Their rotors are absolute junk!!!! Generally, OE front rotors last about 25K miles till I start worrying about the cracks. The Vertex were absolutely shot in less than 9000 miles - and I mean SHOT!!! Cracks completely out to the rotor edge. Also, they warped the first track event I used them.

Spend the money and get decent ones; I've bought OE from Hoehn and (on the car now; no prob. in 700 miles) cryogenically treated from Performance Products.

Oh yeah - car has 67K on it.

Tom T.

Hi,

I completely agree with Ray. Stay away from aftermarket rotors. They are not as good as
factory ones. Remember it is YOUR safety.
With several Porsche dealers running specials
you will only spend another $15 or so per rotor.
I paid under $400 exluding shipping for a full set of OEM rotors from Sunset Porsche. There are
other sources too. Check around. You will be
much happier in the long run.

Tom

George from MD

OK guys- I'm not messing with safety- but was assured these were OEM. They're made by Zimmermann- I've used before with no problems- and I pay (on sale) $64 per.

How do I tell the difference? Who makes the originals? My dealer quotes $150 for a "Porsche" rotor- but the hub on it isn't painted either- and the one I saw looked identical to the Vertex.

Please educate me!

Tom T.

[quote]Originally posted by George from MD:
<strong>OK guys- I'm not messing with safety- but was assured these were OEM. They're made by Zimmermann- I've used before with no problems- and I pay (on sale) $64 per.

How do I tell the difference? Who makes the originals? My dealer quotes $150 for a "Porsche" rotor- but the hub on it isn't painted either- and the one I saw looked identical to the Vertex.

Please educate me!</strong><hr></blockquote>

Hi George,

To my knowledge the Porsche OEM rotor hubs come
painted gray from the factory. So your dealer
might not have the right ones but don;t quote me on that one. In any case
that price is too high so call another dealer.
Try Sunset Porsche in Oregon. All four rotors they sold to me were painted and the price was
almost half of what you were quoted.

Tom
P.S. Not affiliated with Sunset, just a happy
customer.

tom_993

[quote]Originally posted by Tom T.:
<strong>Hi George,
To my knowledge the Porsche OEM rotor hubs come
painted gray from the factory.

Tom
</strong><hr></blockquote>


Tom,
My Porsche OEM replacement rotors came with unpainted hubs. They rusted pretty quickly, so I painted them black with barbeque grill paint.

Tom