Hey guys, I just purchased a 09 g37 coupe and just recently had to replace the radiator due to a leak. It's been a few days since it's been fixed until I decided to check the coolant level in the reservoir. There was no coolant in it at all. Could this be another leak or a faulty water pump? My pockets are hurting so bad right now.

 

Unless you are overheating or actually find a coolant loss then your water pump is likely fine. What likely occurred is after replacing your radiator you didn't get all the air out of the system and it eventually worked out. The air was "replaced" by coolant and the coolant level dropped. You also need to go back over your hose clamps to make sure you don't have any seepage.

 

Water pumps on these cars usually dont fail like normal ones. Usually the seals on them are the failing points.
Replacing the radiator if the person doesnt do a good job it could leave you with air pockets.
A spill free funnel will take care of the bleeding process. The rest is up to you to figure out if there are additional leaks.
If the radiator busted, it probably hurt another coolant hose that you'll just have to find.