Cat 318BL Swing is weak

On our 318BL excavator, everything works fine but the swing seems to be weak on it. No noises or nothing loose etc., just kind of lazy.

Ser # is 3LR00468

Anyone know what pressures should be feeding into the hyd motor? If the motor was quite badly worn would the temp on the outer housing be elevated from bypassing? I have not checked the temps but could do it.

We replaced the main hyd pump a year ago ($$$) & everything else works fine on the excavator.

We don't put a lot of hours on...

Cat 318BL Swing is weak

Cat 318BL Swing is weak