replacement of pump seal

Replacing the pump seal can be done by (1) removing the transmission from the vehicle, (2) sliding the torque converter out of the transmission, (3) using a straight screwdriver or seal puller to remove the seal from the pump, and (4) installing a new seal with a hammer & flat drift tool.

But my bigger concern is why is this seal leaking? Is the rubber lip of the seal dried out? If this is the cause of the leak, then all of the remaining seals in the transmission are also dried out and will begin to leak, eventually.

Is the pump bushing worn, thus allowing the torque converter to move up and down, thus causing the leak?

Does the engine's crankshaft have excessive thrust movement (fore & aft)? This can cause the torque converter to move, thus causing a leak.

Is the fluid overheating, thus causing bubbles i the fluid, which are then released through the vent opening in the pump housing?

All of these possibilities should be considered before condemming only the seal.

Hope this helps,

BILL