Mazak QT15 Turret Problem

WE have a early 90's vintage QT15 that has been having a intermitant turret problem, it goes to index and it un clamps and just sits there, you can bang it with a rubber mallet and it will index usually. It happens in a program as well as manually indexing. If you let it sit long enough it will blow one of two alarms, one is turret clamp malfunction and the other is something about too much time for turret to index. I'm kinda thinking its a prox. switch or something, guess I need to open up the back of the turret housing. Have the turret off now as there was more coolant coming out from behind it than onto the cutting tools, this problem is obvious the brass gadget and seals are toast. The turret rotation problem isn't so obvious, anyone know where the hyd. selenoid valve that activates the turret motor is? maybe that's sticking, I sure hope it's not the turret rotating motor. Any and all ideas and comments are welcomed, Thank you Jon P.

turret unclamp sensor is first thought
you need to get into the diagnostics and check for unclamp confirmation
the fact that you can force it makes me think it is not a directional valve.
those hydraulic index motors can be trouble on an older machine

you will also want to check that your hydraulic pump still has enough volume to run the turret index motor.

You can buy a rebuild kit for the hydraulic-index motors. Or send them off for a rebuild.

Way better than paying Mazak $6,000 for a motor!

Take a spacer just over the length of the splined shaft, tighten the nut to that spacer as much as possible to see if it indexes without the turret on. Just had the same problem on my daewoo lynx and it turned out the nut must not have been able to tighten enough to signal the sensor. Good luck and let me know how ya make out.