Pontiac Repair: antifreeze fluid loss, sensor, coolant loss, rubber hammer

Question
95 grand am with the v6... not sure which one! anti-freeze seeping out. Checked hoses and radiator. checked under vehicle for the green spots. over flow/ fill container... does the plastic ever crack and seep? However I don't see any trail of fluid from around that either... Head gasket?
also the fluid sensor in the resevoir sticks. I have taken the car in only to watch the mechanic use a rubber hammer and hit the resevoir... the light goes off finally however what kind of damage can i get from a plastic resevoir getting hit?
car has about 130,000 runs great! oil is clear.
no seepage into oil!

thanks!

Answer
It is normal for the sensor to stick and hitting it with a rubber hammer is the only way to unstick it.
Try replacing the cap on the surge tank(resevoir) and see if the coolant loss stops. There were some problems with the caps not sealing correctly. If not, it is probably a water pump starting to seap around the seal.