Where is it and have you ever done it before?? After about a 1/2 hour we cant lift the bucket anymore and the rippers wont dig so we think its the hydraulic pump. Got a new one but first we have to get unstuck, and then put the new pump in...
Remove the floor under your feet, hyd pump drives off the converter, you should be able to get it from the top, it's not that bad just cramped alittle. Mite want to pull the belly pans to drain the oil #2 and #3 from the rear and put it on two rail road ties for some room to work. Would be nice to flow it first, did you check the pressure with a gauge it should be 2450-2550 psi, if you remove the cover on the rt/hand side there is a port to check your pressure at the control valve inlet main pressure line.
That is a classic symptom for a bad hyd pump. But there is a flow control valve in the loader control valve which can give a similar result. Like sheepfoot says, a flow test for the pump would help diagnose.