2840 hydraulic pump noise

Newbie here with problem no 2, hydraulic pump is making a thumping noise when I start the tractor, all the hydraulics work even on my fel but you can hear and feel the thumping through the lines. I disconnected the pump from the engine to make sure it was the pump. The isolator was in pretty bad shape that I need to replace, but should I just put a rebuild kit in the pump, I really like to know what is causing the thumping noise, bad bearing or shaft or a piston?????. any help is greatly appreciated Thanks Steve

Usually pulsating in the main pump is caused by insufficient flow being delivered to the pump from the transmission pump circuit. Has the filter been changed, sump screen cleaned, and trans full of oil? It is posible to be a problem with the main pump, but you need to verify it is being supplied with enough oil first.

jd110 I have replaced the transmission filter, today I will check the screen and the filter in the pump, that's the only filter that I see, I changed the trans. control valve o ring because it was leaking, I have checked the oil 3 or 4 times to make sure there was enough in it, after this I don't know what else to check. any advise is greatly appreciated, thanks

update all the filters were clean, will do some more checking tomorrow

Does the noise/vibration stay the same all the time? No dfference if oil is cold or hot? Do the hydraulics seem as fast as they should be? If the drive coupling for the pump is worn, if will definitely make noise, but you said you could feel it as well. That is what concerns me. Maybe it would be a good idea to repair the drive coupling to see what difference that makes.

I changed the cushion and put a pump rebuild kit in the pump just in case, the thumping came back when I first started up but was not as loud and went away, I let it run to get warm and thumping didn't come back. YEA but now I have to put a overhaul kit in the steering, bummer, thanks for the advice jd110, appreciate it greatly, hydraulics is not my strong suit.