I have a '94 850 with 144K on it. Have noticed a rubbing or "whooshing" sound coming from the right front wheel. 1st noticed it last December after big snowstorm (street parking) and thought maybe road salt had gotten onto the rotor or something, because the noise would always appear at startup (once rolling) and then gradually diminish while driving. Also noticed it would "disappear" after a car wash. However, now 7 months later it is becoming more noticeable and seems to diminish less so as the car is driven (but disappears when braking). I've noticed no performance problems whatsoever braking-wise but am obviously concerned I may have metal rubbing on metal - and just haven't wanted to deal with it since I recently dumped a bunch of money into expensive repairs. The noise reminds me of the rubbing noise I get on my mountain bike - front disc brake pads rub on the disc rotor - causes the same effect. My rotors have been warped for a long time due to resurfacing + brake pad replacement a year and a half ago - I was told this wasn't a danger to anything.
Any advice/suggestions/perspective on whether or not this is a huge serious expensive problem appreciated.
Thanks.

On my 850 and other cars, if a brake caliper is sticking noticeably the corresponding wheel will be very hot after 10-20 minutes of driving. To test this pick a drive which doesn't require much stopping and compare the questionable wheel with the others on the car which would be only warm. In extreme cases the brake pedal may become hard to work too. In case of a repeated problem with stuck calipers it might be useful to check the brake fluid for contamination - if debris is contained in it this might move down to the caliper pistons and bind there. Periodically replacing brake fluid (say every 3 years) is probably a good precaution for ABS-equipped cars.

If the noise reliably changes or disappears when you brake or coast - are you sure it isn't a wheel bearing, driveshaft joint or some suspension component?

I notice no difference in the way my brake pedal feels. Also, the sound only disappears when the brake pedal is depressed - otherwise it is completely noticeable while coasting and accelerating (but at slower speeds). Once I've been driving the car for 10 minutes or so, the sound becomes less noticeable and at higher speeds it isn't noticeable at all - so it's as if once the car has been driven, the sound fades and almost disappears - but is right there again at next cold startup & drive. So you're suggesting this may not be the caliper after all?

Hard to say. New OEM rotors are $130 a pair and new front pads are
$45 a pair (www.volvoparts.com) and an hour labor to replace.
So, maybe that is your worse case scenario. But you could also
have a sticky caliper. Not unheard of. Parts and labor for caliper
work would be higher.

Note that volvo pads last about 35K miles and rotors last about
70K miles before they wear out. Longer if you have a manual
transmission (since you probably would use the brakes less).

Thanks, Ray.
In '01 at 116K, the front caliper was "cleaned & serviced" and the front rotors & pads were replaced. Six months later in '02 when the car had 127K on it the rotors were resurfaced and the front pads replaced from aftermarket (=squeal) to OEM's. Interesting to note that at this time the front calipers were "cleaned & serviced" and both rear calipers were replaced due to one of the 2 pistons being frozen. Two new rear rotors and pad set as well. Right lower balljoint also done.

Anyway, if I wait on this, what am I looking at? If the caliper is sticky, will it ultimately freeze - and if so, does this mean that the right front wheel would have no brake action?

REPLACE THE CALIPER, MINE WAS MAKING THE SAME NOISE, SO I DID STOCK VOLVO ROTARS AND BRAKE PADS, AFTER CALIPER WENT AND ATE THRU MY NEW ROTARS I HAD TO REPLACE EVERYTING AGAIN, VERY EXPENSIVE. SOOO JUST DO IT RIGHT THE FIRST TIME AND SAVE YOURSELF THE HEADACHES. KELLY

Thanks.
Any way of knowing how long I have before the thing seizes? I plan on getting this done ASAP by a good indie. Just don't want it seizing while I'm driving it as I assume this is dangerous.

well mine lasted about 6 months, then one day the darn thing went right thru rotar,made awful noise, I was about 15 miles from home and on a lunch break, I figured I had 3 other brakes and the one was already messed up so I drove home carefully. I have a friend with a lift in his garage but I spent the weekend running around looking for calipers, volvo didnt have them in stock, so order way ahead of time. did find a place near atlantic city and they had them shipped from philly that day, but they were expensive, more than if I would have waited from volvo. my car came from upstate new york with one previous owner who had it seviced from volvo, I figured it was taken care of, I didnt take into consideration the salt factor. my friend had to blow torch the calipers off. he wants me to sell it and get a chevy trailblazer. ive notice other things rusting so I replace as I go. I live on the jersey shore so I figured eventually it will be a pile of rust from the salt air. good luck with it and if it goes drive home carefully. kelly

See what your friend thinks of this link- I've never been impressed with Chevy's safety design. Maybe there is a middle ground. The newer Colorado has tested really well, maybe that will trickle down in a few model years...

http://www.hwysafety.org/vehicle_ratings/ce/html/0119.htm