True, but not really....The lexus SC400 calipers should not go out, I owned a used dealer ship for a few years and bought and sold altleast 50 or more SC400 and LS400 and some with super high mileage too. Not one ever had a caliper piston problem...Also I know a few heads in the lexus dealership and they tell me the calipers are very solid...If any are to go bad it would usually be the fronts as they support nearly 75% of the cars breaking power, and the rears contribute to only around 25%...Any used SC4 rear brake caliper should be in good shape 99% of the time...Your failed rear caliper is very uncommon....Just my 2 cents...
Rebuilding to new status is a good idea, however I am wondering if there is manufacturing defect going on with your single rear caliper..Hope the problem doesn't come back after rebuilding....How many miles are on your car?
i actually had a lr caliper go bad on a 95 sc3 i owned. i had 3 sc3's and 1 sc4 and that was the only caliper problem.