Having owned and maitained about 20, mostly GM cars in the 70 - 90 era I have a lot of old power steering and engine oil pumps. Now I need to pump waste vegetable oil through a de-watering and particulate (3 micron) filter to a storage tank. I have looked at the price of a commercial item and am horrified. It needs quite a small flow at about 50 psi.
I have looked at engine oil pumps and they have a pressure relief valve that just releases into the sump. I was thinking of putting a much heavier spring in so it will not operate, but the PS pumps do not have this problem.
Given that I am willing to modify and sacrifice any old pumps I have, I rigged up a motor drive to an old PS pump and filled it up with WVO with the outlet connected to the inlet. It was only running at about
100 rpm but nothing at all happened. It did not prime or circulate. Thinking I had a broken pump I tried another with the same result. Both these pumps were working when I took them off old engines and I wonder why this should be. I assume that looking from the "front" the pump will rotate clockwise. ( I did reverse the rotation of the motor, but it did not change anything.) The oil is obviously a bit thicker than Auto transmission fluid, but I thought it would pump in the end, if only for a short while. I assume that these pumps are gear type and if I could get the pulley off, (does it just pull off?) I would get it apart to see what is happening.Can any one explain this and suggest the best way to cheaply pump veg. oil
Thanks for any suggestions George.