I picked up a big old parts washer from an auction for almost nothing. It doesn't look like the tank leaks and the motor turns on, so I think it is serviceable. I'll pick up a new filter and get the gunk cleaned out but before I invest in a bunch of solvent (looks like I'll need 10-20 gallons) I want to actually run the pump to make sure it actually pumps fluid OK. Is there any reason I can't fill it with water to do a test run and make sure the pump works? I'm not going to run for a long time (i.e. pump lube problems). But I don't know if these pumps will be otherwise negatively affected by running water through them.