I just had new brakes put on my blazer 2 days ago, and all 4 are making a grinding noise all the time. Only stops making noise when i'm stopped....

My mechanic told me this is normal and the brakes need to wear in, this could take a week or so before the noise goes away....

Now can anyone tell me if this is correct?

Welcome Aboard!

If the caliper pistons are not sticking, and the calipers are not sticking in their brackets, the noise should disappear after about 4-5 good stops to bed-in the pads. If the rotors had some surface damage and were not turned or replaced, the noise may persist longer.

The pads' friction material will also affect the noise produced. Plain "organic" material and semi-metallics tend to bed-in quickly. Carbon-metallics and ceramics tend to take a bit longer to seat, and may produce some squealing in normal operation.

As long as you are certain that the calipers are moving freely, the pads were installed correctly (with the proper shims and clips where necessary), and the rotors are in good condition, the noise should subside.

Does the noise occur even when the brakes are not applied?