The answer is yes and yes. Many refrigeration supply houses in big cities carry direct drive pump oil for refrigeration technician servicers system exhausting pumps.
I use this local source for all of my direct drive oil.
Direct drive oil is usually less viscous that belt drive oil and will work fine, but might not allow the depth of pumping when hot in a belt drive system.
Likewise, belt drive oil will work ok in a direct drive pump PROVIDED it never gets below room temperature. My big lab is un-heated in winter and any direct drive pump I have out there where I had used a more viscous direct drive oil, would not start in temperatures below freezing!! You also run the risk of overheating a marginal motor is you throw belt drive oil in a direct drive pump.
Direct drives are sonically nerve racking to me, but allow a portability that is very nice. They trade off the need for massive chamber volume against rotational speed to obtain decent pumping speeds. This makes them rather noisey and grating on the nerves, long term.
Belt drives are a study in unfettered inertia. The clasic immovable objects. However, their slow pace and gentle, quiet, blup, blup, blup is almost soothing to the psyhce is a modern fast paced, racket laden world.
The 35 micron 1400 is probably OK. A flushing with two or three oil changes with good belt drive pump oil should lower that a bit.
Richard Hull
Created on Wednesday, March 14, 2001 11:07 AM EDT by Richard Hull