I have just purchased a Sauer/Danfoss 151-315 orbital motor with the hopes of using it on my EX aux circuit. It is new but been unused and stored for at least 5 years. It has hoses that were plugged and clean and was originally tested ok apparently. It is not seized but when you rotate the shaft with the aid of a spanner it is obviously notchy due to the gerotor but it has some very tight spots as you are turning shaft.(Locks the shaft and you have to change direction to free) When you rock the shaft over the tight spot it seems to move to another location in the circle. Are they normally like this or do you think the Gerotor might have damage or corrosion on some of the lobes. I don't want bearing material or debris to be ingested into my EX so do you think it needs to be stripped or they are normally like this when you turn by hand??. Any help Appreciated.
Some observations/questions/suggestions, in no particular order; A new hydraulic motor kept clean, full of oil and stored for five years should be as good as new. When you're rotating the shaft manually, are the hoses blanked off? If they are, the motor will be hard to turn. If in doubt, connect the pressure line from your HEX to the motor and the return line from the motor into a bucket. Give the motor a test run and if it's bad, the debris won't be circulated into your hydraulic tank.
Thanks for Rep. The plugs were leaking a little oil but must not have been stored full of oil. So internals were exposed to air all that time. Hoses open to air when i was turning. Probably a good idea what you suggest, i might just give it a quick blast into a super clean bucket and see if any visible debris comes through. If the motor is a bit pitted on the gerotor lobs how long do they last in service or is that taking the risk of putting fine metal flakes in my EX?