The 1/2" pipe is a return pipe for the hyd. the pipe has o rings on both ends, alot of times the o rings leak because something hit the pipe or block, you will have to remove the block and the pipe will pull out of the block and transmition case. If the bracket that the block is mounted too is bent you will have to straighten or replace it. The o rings will not seal if the pipe is on a angle.
Paul, June 2009
