This is the beginning of a process, I would add the Dye, so if the unit does slow in performance, we will be able to return and track down where the leak is. Then we can determine if a coil needs to be replaced or needs a braised repair. This is just a estimate once I weigh it and I will be able to give an exact amount. This is the beginning of a process, I would add the Dye, so if the unit does slow in performance, we will be able to return and track down where the leak is. Then we can determine if a coil needs to be replaced or needs a braised repair. This is just a estimate once I weigh it and I will be able to give an exact amount. Returned a couple days later and put 6 pounds of 410 in unit and added dye. Unit has a 22° temperature differential at departure and told customer to give us a call in a couple months to locate leak unless units slows in performance.