<<Why is oil Dyne charging you anything?  They installed the spool valve backwards didn't they?  Seems they should just be glad that it didn't cause other problems....>>

The spool valve can be installed either way. Its orientation depends on whether the shaft-side of the hydraulic cylinder is connected to the low or high side of the pump (i.e. other users of the pump may use the pump with the cylinders flipped 180 as compared to our configuration). The amount of fluid that must return to the tank during cycling of the cylinder differs by the volume of hydraulic fluid displaced by the shaft inside the cylinder. The spool valve takes care of this problem. The company ships pumps with the spool valve oriented both ways. I'm not sure how the error was made or who is responsible, but some of us received pumps configured incorrectly for application. It may not have been Oildyne's fault.

I've posted this before: A simple test to check if your spool valve is okay is to put the plane on jacks and raise the gear. With the gear 95% up, put the switch back in the down position. The pump should stop and reverse immediately, and the gear should start back down. If the pump just stops and then delays before reversing, then the spool valve is probably in backwards. Depending on the pressure switch settings, and the low-side pressure relief-valve setting, the delay may be a few seconds to maybe 10  or 20. In my case, it was closer to 20.

Mike Reinath
360 at 146 hours
N3602M