Leaking how do you know if the pump is bad

yes it will leak. there is a weep hole on the pump that will leak coolant when the pump is bad.

Any time ANY vehicle leaks at that weep hole, it's because the seal in the water pump has gone bad. All water pumps have this same weep hole in the same position to let you know the seal is bad. Makes no difference if it has a penny over the hole or not, replace the water pump and it won't "p" on you any more.

Water pumps usually have a weep hole on the bottom of the snout. This is put there so when the seals go bad you will know from the water leaking out. Try to look for that weep hole and see if coolant is coming from there before spending money on a pump. If the pump does not look as if it has been leaking then maybe its just the hose.
Not knowing what Pontiac car (or Truck) you are working on and what hose specificly. When asking for the hose at the store just tell them where it goes to. Water pump bypass, water pump to intake, water pump to heater core, etc..

If it is leaking behind it, you will need to replace the water pump and gasket. The new (can purchase a remanufactured pump, cheaper) pump will (should) come with the gasket.
Please let me know if you need assistance with removal and installation.
carsandcomps,
Guru, Premium Expert, Phone Support @ Fixya.com

sometimes it makes noise But uselley you can tell by leaking and the owner's manual always tells yout to replace it around 60.000 to 90.000 that means when you are changing the timing belt as well.

Are you sure this isn't a "weep hole"? Many water pumps have them, and they leak when the pump has gone bad. Plugging them won't help, and could cause engine failure.

You can check for play in the pulley or if it is leaking and yes there is a hole in the bottom of water pumps that can leak when they are bad.

YOU EITHER HAVE ALOT OF AIR IN IT AND IT'S NOISY ALSO OR JUST A BAD PUMP,REMAN PUMP ARE COMMON FOR BEING BAD. IT TAKES MERCON FLUID,MAKE SURE YOU DON'T HAVE ANYTHING ELSE IN THERE. YOU CAN USE MERCON V ALSO. YOU'RE NOT GETTING ASSIST MAYBE RACK IS BAD,IF IT LEAKS SEALS MAY BE BAD ALSO LETTING IN AIR. LOOK AT YOUR LINES,MAKE SURE NO LEAKS OR BINDING. DID YOU ALSO REPLACE TEFLON O-RING AT PUMP.

Water leaking from the bottom usually indicates either a bad hose , bad hose connection to the pump or a leaking pump. Also sounds like the machine is not spinning out. Is there water left in the tub at the end of the cycle?