I've seen a few messages about the o-ring size for the S80. In some of the cars that I've sold and also serviced, we're getting leaking o-rings out the ying-yang. Same old story, wet carpet and low coolant message.

Given the frequency and age of the cars out there, any 2002 or later probably has developed some leaking. Catch it now and it is not near of the job to clean up than after you dump a quart or two or coolant into the carpet.

I've found that a #13 o-ring 7/8 outside diameter, 11/16 inside diameter and 3/32 thick replacates the OE just fine. Use those. The originals start to disintegrate and turn into this black powdery mess.

Give it a try.