If you are going to pull the trans to change the front seal, you might as well pull the pump to change the pump o-ring. If you're pulling the pump, it'll only take a few more minutes to check all of the clutches for overheating. If they were overheating then the piston seals are bad, if not, then throw it back together with a new shifter shaft seal and dipstick o-ring too. That should solve any front leaking problems.