My Yukon is a 1993 model originaly automatic and later converted to manual ahifting. Original parts from a 1996 model was used and all genuine GMC components. Started slipping about a month ago. all the clutch system was replaced still with genuine parts top auxiliary pump, main pump , plate ,pressure plate and clutch plate. Probvlem iss still present. Localk mechanic advises thtat hose between the two pumps be replaced as many models had the same problem. code number for this hose is 628105. It has a connection in mikd hose that I understand is tricky to uncouple and that it may be the problem for pressure to rlease. Please help.