I have a 1999 kobelco sk 150 ymu 2043. everything works good except the lift cylinders. they are really slow like the 2nd pump is not cutting on as it should. wondering what would cause this problem and were i should start to try and fix it. thanks. rion
First off will this machine track strait? Do you have pressure gages to install on P1 andP2? They should be 10,000 psi gages. This will verify or not that P2 is coming on board or if you have other valve problems. There is a pilot line that tees at the boom spool and runs around to the P2 side of the hyd valve and strokes the neutral cut and the boom conflux spool that brings in P2. but without gages in the pumps we are only gessing. Does the boom drift?
I just remembered, there are orfices in the fittings where the pilot lines go to the boom spool, you can remove these an see that they are clean.