Please scroll down for updates below…..
As a follow-up to the backwards brakes posting…..
Ted found an interesting thread over at SaabNet that discussed this issue and in that thread, it was stated that the grooves should “attack” the pads (i.e. the outer part of the slot hits the pad first). This statement is coming from Brembo’s website.
Taking a look at the photos I placed on the original post (see above link) that would mean that the front wheel I photographed is correct and the back wheel I photographed is correct. Of the Saab stock photos, the front wheel on the convertible (high contrast photo) is correct but the front wheel close-up is actually fitted incorrectly.
I had a close look at all my wheels this morning and it seems that both of my rear wheels are correct. The curious thing is that I have one correct wheel in the front (LHS as photographed) but the rotor on the RHS is incorrect. What makes this even more curious is that the incorrectly fitted rotor in the Saab stock photo is also a RHS wheel.
Now the issue becomes one of whether or not this is correctable.
i.e. the new front rotors that were installed back in November were ordered as a pair. Did they send a mismatched pair or are they all like this?
I haven’t noticed any problems with my braking at all, but it’ll be interesting to see what the outcome is.
Matt the Fudgepacker – any input you might have on this would be welcome.
The following has been sent off to Saab Aust via their website. I’ll let you all know of any answers that are forthcoming.
Hi Saab Aust,
I have a 1999 9-3 Viggen and my attention has just been drawn to an anomaly with my brake rotors.
As you know, the rotors on the Viggen are slotted rotors. I had my rotors replaced when I purchased the car back in November 2005. I’ve only now had my attention drawn to the fact that the slots in the rotors point different ways on each of the front rotors.
On the LHS the slots are directed so that they ‘attack’ the brake pad, i.e. the outermost point of the slot hits the pad first. On the RHS rotor, this is reversed and the innermost part of the slot hits the pad first.
I have posted pictures and a summary of the issue at the following website, which I invite you to take a look at.
I’d like to resolve the issue and find out if a) the rotors are, in fact, meant to be oriented in a specific manner (i.e ‘attacking’ the pad or otherwise), and/or b) if the orientation of the rotors, or more specifically the slots in the rotors, is likely to have any detrimental effect on brake performance or wear.
Your assistance with the above would be appreciated.
Just a few hours after my query, a very quick reply from Saab Australia:
Thank you for contacting Saab Australia.
A couple of points:
Viggen Rotors are not directional.
As the grooves do not connect to the internal venting of the disc they have no real effect on cooling.
Regardless of direction the surface area of pad to rotor will remain the same, and therefore brake force will be consistent.
Hope this helps,
Thanks to Saab Oz for the very quick response.