just bought a tank at the weekend from a farm sale. year 2008. mec 8000 pump on it. the pump turns freely by hand yet when operated on the tractor it gets hot and the oil turns to smoke. it is getting plenty of oil, have changed the oil for the propper stuff and its still the same. there are no restrictions in the pipe or the fill valve, any ideas?

Hi, Is it sucking and blowing? I'm sure its on the 540 shaft? Could be a bearing or blades, its not getting to much oil?

Are you sure that it is oil smoke you are seeing???? These pumps will tend to look like they are smoking, but in reality it is just vapour, much like when we breath on a cold day. Alternatively one of the vanes could have tipped. These pumps work by use of floating vanes and as they wear right down they tip and can burn, although the pump would be very stiff to turn by hand if that was the case. Your best bet may well be to strip the pump down and give it a darn good clean anyway just to make sure, the vanes to rebuild them are not expensive.

cheers for the advice, its definatly smoke not vapour, can you over oil these pumps ? how much oil do these pumps need anyway?

Its should be equipped with an adjustable oiler with a little sight glass, you get a steady drip........drip.......drip from it, not a costant stream. Excess oil shouldnt hurt the pump at all, but may discharge a small amount from the exhaust. Are you sure that your running at 540 rpm PTO and not 1000?? That is the only other thing that could cause the pump to get hot. Unless of course something has been sucked into the pump by the inlet/exhaust outlet, i did manage to get a glove sucked of my hand ad straight into the pump many years back!!!

you can clean pump by sucking in 1 pint of diesel through pump exhaust.15 drops of vacuum pump oil per minute is the amount needed for your pump.

 Agree with earlier post, Strip it and properly clean it, and put in fresh vanes They should be free to move in the slots, like as been said they're not expensive, and gives opertunity to inspec the bearings for play and wear.