Sounds like Paul lives somewhere where rust is not a big problem. I don't try to remove rear rotors unless I already have new ones, because getting them off without destroying them is a challenge. A suitable application of high explosives would be the tool of choice for this job.

If they look OK (not deeply grooved in the track where the pads touch), and your pedal does not pulse, indicating warpage, they probably are OK. It will take a few miles for new pads to take the shape of worn rotors, but after the first 100 miles, you won't know the difference.

Turning rotors has become a bit of a lost art because the manufacturers can shave off unsprug weight by making the new rotors as thin as possible. The manuf recommendation for my wife's car is to replace the rotors every time the pads are replaced. That didn't happen.

You need to measure the width and run out of the calipers to really know if you can turn them or replace them. Rear rotors are thinner and wear much slower than the front ones unless you have a hard petal stabber in the family. The softer you brake the longer rear brakes will last. Most of the time pads on the rear of my 245 will last at least twice as long as the front ones.

A couple of tips if you do want to pull of the rotors. Loosen the lug nuts on both wheels, but do not remove them, then chock the front wheels before you raise the back end. I use the pumpkin in the middle of the axle as the jack point and then set the rear jack points down into jacks stands. This is very important, you want the emergency brake off when you are pulling off the rotors. There are drum brake pads inside the rotor that will keep the rotor from coming off unless the handle on the Emergency Brake is all the way down. After you get the tire off, the only part of the rotor you can see will be able to see is the front. There are two nuts on the backside holding the caliper on (18mm I think) and you will have take them out and then hang the caliper up out of with wire before you remove the rotor. Remove the the 10mm guide pin, and hit it with PB Blaster. Had to use a wheel puller to get one of mine off this weekend the other side came off with a dead blow hammer. Had to replace two studs in the rear hub since the last time my tires were rotated two lug nuts were cross threaded on there.

Once you get the rotor off you can measure the width and run out and decide new or turned. I had metal left for another turning, but the place that did a good job turning rotors has a broken lathe and has not gotten it repaired. The chain auto parts stores who claim to turn rotors here have stupid untrained knuckle dragging green horn morons running the equipment. When I went there to get my front ones turned the guy came out and said the rotors were too thin so he could not turn them. Opened the green book, grabbed his caliper and checked one. He had an SAE Caliper and it read around an inch (like .990) I think. He said the spec was over 200 something so these were way too thin. Of course that limit was in Metric not SAE and he had no idea what the difference was.

So opted for a new pair this time and they were less than $30 each. If you have never done ATE brakes they are held in by two drift pins you tap out from the front. There is a single anti-rattle spring that goes under the two pins, so mentally note how that fits in there.

Good Luck and Regards,

Paul

When you change them is completely independent of the front ones-- change them when they are worn beyond spec.

Good luck!