Found leak on 3/8 soft copper under bathroom sink on push on fitting. Took sink stop off, removed leaking plastic push on fitting. Replaced fitting with 3/8 x 1/2 shark bite fitting and 1/2 in shark bite male adapter. Put sink stop back on. Copper pipe still had leak. Took shark bites back off and cut off 3/8 copper pipe back to clean/undamaged copper and put shark bites back on. Verified no leaks under sink on fittings.