The pump in our basement bathroom use to make a loud clunking noise when it was finished pumping out. It no longer does that. You can hear the water running out but not with the force it use to. There is a smell in the closet where the pump is housed. We had the septic tank pumped to see if this was the problem. We are not familiar with this system and could use any suggestions. Do you think we need a new pump? We are totally clueless. Thanks

The "clunk" you heard was probably the check valve closing. Since you don't hear any sound it may have gone bad. If it's faulty you would hear water draining back into the pit. The first thing I would check is the check valve. The next would be the pit seals and the last would be the pit vent. Good luck, Tom