just ordered a set of ExtremeContact DW tires from Tirerack. Should I service the tire pressure sensors when I get them mounted? Are they even serviceable? Need replacement batteries? Figure since they are going on 7 years now, rather be proactive then have to deal with stupid TPMS issues later on.

 

No. You don't have to unless you want too. Cant replace batteries, you will have to replace the whole sensor. Most places will reset the tpms for you for free. Well I know Americas tire/ discount tires will.

 

^^The sensors can be "serviced" when you replace tires. I'm not sure what they change out but it has nothing to do with the batteries. A lot of tire places will do this but it's an extra charge. I've always wondered the answer as to when this needs to be done so I'm in for a definitive answer. OP if the wheels are 7 years old I think it would be a good idea.........

 

The kit includes 4 parts usually and every time a tpms is removed or "serviced" the kit needs to be used to replace parts of the sensor.

As noted above, the battery is not replaceable and is the main reason a new sensor has to be bought.