We just completed major inspection on GE Frame 900le turbine with Elin Generator train. During pre-commissioning process we realized the jacking oil pump was delivering at normal pressures in ranges of 2400-2700psi for both bearing # 4 & 5, but never observe any lift of the generator shaft with dial indicators mounted at TE and CE. We suspected the check valves were bad and replaced but still no lift was observed.
We did pressure balance on both bearing, but still no lift observed.
Please what could be the possible cause of such a situation that the jacking oil pump is delivering at required pressures, but the generator shaft is not lifting?