I have recently purchased a 9150 MFWD from a AGCO dealer, the tractor seems to be a White rear end, main frame, over/under, and a modified white cab.  The Front axel has a german stamp on it, and it has the Deutz air cooled powerplant and Deutz hood and front sheetmetal.  The tractor seems to be solid, it has 4600 hours.  I have the tractor on the feed wagon, a Schuler SRM353. The problem that I have noticed is there is a audible alarm and indicator lamp for (transmission lube pressure low) this happens when you go to unload and have the discharge conveyor running while opening or closing the side door or light pressure on the foot brake.  I am wondering if my hydraulic pump is weak or the filter is cloged, I did not notice the problem before it turned cold, and it doesn't seem to be low on oil.  When I purchased it the dealer said that they had changed all the fluids and filters, they also said that they sold the tractor to the prior owner in 1991 when it was new and its primary use was planter duty.  Any help or advice is appreciated, I will prolly call the dealer and see what they have to say as well but not looking to take it back for service since they are about 170 miles away.  Thanks!!