My 2130 tractor made noise when I started it this morning and I have no Hyd. and no steering, rockshaft,ect.. It worked great yesterday and for the last year that I have had it. I looped supply lines uder shift cover to bypass pto and shift cover and had lots of oil flow. I removed hose at top of oil cooler and oil doesn't come out there, but it comes out of resevoir tank above air filter. I was sure it was supposed to run the other direction. Is there anything that would cause this. The noise by the way come from main pump, I presume from not getting oil its not a cavitating noise but more sounds like a cold hydrostatic transmission. I am going to check flow control valve next. If the destroking valve got stuck would it cause this? Any ideas would be greatly appreciated for I am stumped.