Loud Grinding from Wheel (?) No Warning Lights
 

I have a 2001 Volvo C70, and I love it! But, this morning, I noticed a loud grinding noise coming from the passenger front tire (I think). The noise begins when I start braking, but does not always stop when I begin accelerating, until I reach ~25mph or so. No warning lights are on. Also, it might be my imagination, but I thought I felt the car slide a few times.

I'm sure it has something to do with the brakes, but I know nothing about cars. Just looking for somewhere to start. Does anyone have any ideas?

It could be a number of things.

1. After a drive touch the wheel to see if its hot (feel both sides for compare). If it is then the brake caliper is most likely sticking and dragging on the disc.

2. You may have picked up a stone of another object which is jammed and rubbing on the disc.

3. A brake pipe has become loose and is rubbing.

4. Part of the plastic wheel arch liner is loose and rubbing

Either way your going to have to remove the wheel and get it checked. If your unsure yourself then perhaps a tyre center etc.

Also, see if it pulls to that side when you let go of the steering wheel. This will also help determine if it's the caliper that is sticking.

Raise the front end on jack stands. Check for loose wheel, bad ball joints etc by grabbing the tire @ 12 & 6 o'clock wiggle tire/rim. Then do 3 & 9 o'clock wiggle. Remove tire/rim inspect rotor & caliper/brake pads. Spin rotor with caliper installed then remove caliper & spin rotor. Maybe remove rotor to inspect wheel bearing.

Wheel Bearing.

sounds like the brake pads are worn out more than likely your pads on one side are rubbing metal to metal. this will create a loss of stopping power on that side generating a pull. you may have a frozen caliper or caliper slide. The repair is fairly simple I recently bought front rotors for mine for about $30 each brake pads ran me $65 for high end ceramic pads I got all this at my local Napa store. take a look at www.napaonline.com for location and pricing.
Replacing pads and rotors is a fairly easy task plenty of video's to show you how on you tube good luck if you have any questions I will be happy to try and help. If you want to replace the calipers yourself just be careful as you will need to properly bleed out the air from the brake system.

After checking and replacing the wheel bearings. I would perform the inspection & possible replacement of the before mentioned brake parts. These Volvo break calipers & pads are probably the easiest of any vehicle I have done in 50 years. A good shop can inspect rotors for balance & run out. Maybe turn them if enough metal is there. Be sure to put anti-seize on all bolts & moving surfaces. Bleeding air out is critical all around. Sequence right rear, left front, left rear then right front. Always cross pattern, brake fluid cap off master brake cylinder. Good luck. Just did this to wife's Linc, bearings, rotors, calipers & pads after 90k miles. Now 65mph hands off wheel on freeway perfect alignment, no vibration. Had thrust alignment performed. Good for another 100k on all but pads! Good luck!