1999 mercury sable ge losing coolant from overflow tank on short drive not overheating

SOURCE: 1996 Mercury Sable Wagon Overheating

sometimes the radiator is just too plugged to respond to flushing. (happens a lot with a marginal radiator because when flushing, the solvent simply goes around the plugged area, and cannot build up enough force to break it free). From what you have written, this may be the case. Is the electric fan coming on and off at the right times? if not this also can give you similar problems. You have done the right things but may not have gotten the desired result. Hope this info helps you a bit.
good luck

SOURCE: '97 Mercury Sable coolant leak coming from under

after you run the car for a while do you see that the oil on your dip stick looks milky? if so the leak is getting into the oil. If so this may be a blown head gasket.

SOURCE: power steering leak on passengers side of 1999 mercury sable.

If it "RED" in color, like p/s fluid, and coming from the BOOT, then its your p/s rack assembly.The unit has to be replaced and alignment reset. ..also check the HOSES they are prone to leak also...hope this helped..GL

SOURCE: 2002 sable radiator overheating

It can be added to th overflow tank..
Do NOT open the radiator cap whaile hot..

When fluid s put into the overflow tank - it can be a bit slow going into the radiator..

Good luck !!

SOURCE: i changed spark plugs and car still misfires and

i bet your spark plug wires are bad. Arching is occuring (when the spark doesnt get to the plug) Probably because of old cracked wires