I just purchased a 1999 S70 (base model with automatic) from a used car dealer with 89k kms. I noticed an intermittent squeek noise that appeared to be coming from the wheels when I applied the brake as I pulled off the freeway on my way home from the dealer yesterday. The sound was not there when I test drove the car. I only can hear the sound at speeds under 20km/h. As speed increases the frequency of the squeek increases until the sound of the car drowns out the sound. The brakes feel perfectly smooth at the pedal and they are strong when I apply them.

I also noticed the garage rotated the tires so there is a new tire on the rear driver side and a new tire on the front passenger side. Is there any good reason why they rotated the tires rather than just put two new ones up front?

Does this sound like the garage that installed the new tires tightened the rims to the wrong torque? I noticed a thread on the Brickboard about over tightening the rims potentially causing damage to the rear rotors. Could a small pebble in the caliper could cause this sound or is it possible the parking brake is dragging?

I'm reluctant to go on a road trip this weekend until I know what the sound is. The used car dealer told me they don't know what was done to certify the car, and the garage that certified the car is closed for the weekend. Unfortnately, I will have to wait until next week to take the car to the Volvo dealer to have it inspected because they are also closed on the weekend.

Any suggestions are greatly appreciated.