Is there anyone here who can tell me how to check the oil level in the engine injector pump? it is my understanding that the pump has its own oil and is not oiled by the engine. I have found the fill port by removing the vent at the rear of the pump on the govenor housing and I have found the drain port on the bottom of the pump, however I can find no information as to how much oil it should hold? I thought about draining it and measuring the quantity that is in it now. but since I purchased it used I have no way of knowing its status now, whether it is low and needs serviced or has the correct amount. any information someone has for me will be really appreciated. I have three service manuals on this tractor and none of them has this information.