When I recently had the tires of my 81 380sl rotated, the Midas
mechanic noticed a shallow groove -- he called a heat crack -- running
radially from the edge to the center of the rear, left rotor. He said
it was nothing to worry about, and that it should pass PA inspection
anyway, since the rotor was over .375" thick. Surprisingly, I was
expecting him to try to sell me rotors in addition to the pads I know
I needed.

However, I'm still not so sure about either of his statements. And
since I have to replace the rear pads, anyway, I guess I should
replace the cracked rotor while I'm at it.

I was just wondering if heat cracks were common in Mercedes rotors;
whether I should change both rotors at the same time; and how
difficult that is. (I read in past posts that Mercedes used Locktite
on the hub bolts of some models, which made them extremely difficult
to loosen, but it didn't mention 107's.)

Thanks a lot in advance for the info guys.

Bill