Coolant Sensor cleaning/service

I have a '98 GS w/ 166k mi.
The low coolant light has come on. The radiator is full, temperature is normal, no apparent leaks. The Dexcool has been replaced a couple of times since new. It looks clean except for the usual scum around the cap & neck.
In a previous post RICHTAZZ said that the coolant sensor sometimes gets gunked up & gives a bad signal.
Can anyone tell me what's involved to check & clean the sensor?
I can barely see it alongside the radiator. I think the battery will have to be removed to get to it. I assume the radiator will have to be drained. What else?
Thanks

Any air in the system? The sensor is difficult to "clean" and a new one cost about 50 bucks. It is very easy to remove, once you gain access. All you have to do is slide the retaining clip off and pull the sensor out. You will not need to drain the radiator anymore than below the level of the sensor.

The sensor looks like this:


http://img141.imageshack.us/img141/8073/coolantlevelsensorkh3.jpg

I think the battery will have to be removed to get to it.

You can remove the battery if you like since there is only a few inches clearance but believe it or not you can access the coolant level sensor by removing the headlamp assembly.

probably a long shot, but you might check the overflow container and make sure the tubing is still attached to the underside of the top. My tubing slipped off a while back and caused the same problem. After re-attaching the tubing with a ziptie, problem solved.

Best of luck.

Mark

BNaylor & forensicscientist:
Thanks for the replys. I will work on it this week-end.
I did check the overflow bottle & hoses-scummy but intact.
Also checked the air bleed-no air.
I think I will use the opportunity to flush & replace coolant.
I have been told that "extended" life (or service?) antifreeze will work as well (some say better) than Dexcool, with no adverse effect.
Any opinions about that?
Thanks again,

The 5/150 EL coolants work well but IMO not necessarily better than Dex-cool. I use Prestone EL (yellow) in my wife's Regal LS and Dex-cool in my GS. The scummy or slimy feel and minor stuff at the filler neck is normal even with the aftermarket coolants. As long as it is not that brown pasty sludge which would indicate there may be other issues. Before switching over definitely do a thorough flush of the cooling system and remove /clean out the coolant reservoir. We have a good procedure posted that I use. Just check some past threads.