[Glenna]

The front left wheel of my boyfriend's Viggen always gets dirtier than all the other wheels (from brake dust). Why? Could it be a worn pad?

Also, at times (when he is driving past a building), he can hear a slight scraping noise coming from the front left wheel.

Anyone know what this might be from?

Thanks!

 

[Zaphod Beeblebrox]

The scrapping could indicate low thickness of material, or a stone in the pad (nasty ), or that a clip has come adrift. Worth immediate investigation, IMHO, as this may damage the discs themselves, as does any doubts about brakes! IIRC, however, the viggen has a low brake pad warning light.

HTH

 

[PMI]

If by dirtier you mean dark grey or black brake dust, it means that on one side, the disc brake pads are wearing more than on the other side. That could also explain the scraping, because a worn pad could be scraping along the rotor.

Or the brakes could just be wearing unevenly and calipers might need cleaning and servicing after the winter even if pads are not worn out. Hard to tell unless someone takes a really good look at the brakes, meaning pads, rotors, and calipers with the wheels off.

 

[Slaab4life]

front left wheel of my boyfriend's Viggen always gets dirtier than all the other wheels (from brake dust).

The only wheel you can compare the front left wheel to is the front right wheel. Significant dust on the front wheels. After a few months if I don't clean the dust it looks like I have silver rims on the rear, and black rims on the front. I would say the combination of extra dust and the noise would indicate a possibly sticky caliper that isn't pulling away from the rotor after braking. I'd pull the pads out, perhaps the caliper too and give it all a good cleaning first.
Then again, how sure is he that its the front and not the rear? I seem to have incorrectly adjusted my handbrake, causing the brake shoe to slightly rub on the rotor, thus making a noise.

 

[PMI]

... I seem to have incorrectly adjusted my handbrake, causing the brake shoe to slightly rub on the rotor, thus making a noise.

Watch the handbrake. You don't really hear them scraping unless something is wrong. That is exactly what I thought, incorrectly adjusted.

Instead what I was hearing was the lining separating from the shoe, as the last result of a stuck cable, leading to a bad adjustment, rusted expander, and finally the lining coming off. The shoe wore such a deep groove into the inside of the rotor I could hardly get it off.

 

[Glenna]

Would having that noise diagnosed at a Saab dealership be covered under warranty?

 

[PMI]

If there is something out of the ordinary like a stuck caliper, it should be covered. Normal wear on brakes is usually not. Call and ask.

If all they try to do is make money off the fact your car is under warranty, it will be easy to tell. A service manager out to make a fast buck will try to convince you that you should pay for a complete brake job first, and "if that does not fix the problem" they will look for the cause.

Someone with a little integrity will first find out what is causing the problem and fix that under warranty. Then if you still need pads, they will charge you for those. I would take the car to an independent mechanic or chain first, and get a quote before I would go to a dealer. Brake jobs on a Viggen are too expensive to just throw parts on the car hoping the problem will fix itself.