High Clutch Piston

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Make sure check balls are not fixed.
Apply compressed air to check ball oil hole opposite the return spring. Make sure there is no air leakage.

Fig 1: Applying Compressed Air To Oil Hole
Courtesy of NISSAN MOTOR CO., U.S.A.
Apply compressed air to oil hole on return spring side to make sure air leaks past ball.