You know, I did have that problem with one of those Hysters. After overloading my brain, I noticed the valve had a 3rd spool that wasn't being used. I moved the tilt hoses over to it and connected the lever and bingo it worked perfect. So, I think that tilt spool has something special about it, maybe a tilt lock feature that was malfunctioning. Anyway, it had to be something wrong with the tilt valve spool, but the customer said he was happy the way I switched it and don't pull the valve out for repair.