I would be interested to know who rebuilt your calipers. I just replaced three (one front DEFINITELY frozen, two rear were very bad looking) and I got them from Advance, Cardone was the rebuilder. One initial irritant was that the good MB bleeder valves made of brass were replaced with cheap-a$$ aluminum and plastic garbage. The calipers were sent in loose-fitting boxes, and one of the aluminum bleeders was bent. I didn't notice it until I was bleeding the brakes - on my initial bleeding attempt it snapped it in half while I was loosening the brakes, requiring an ez-out to remove it. I looked on the 'net and Cardone has ISO, etc up the yin-yang, but we'll see. Couldn't argue with the price.