Hi,i have a 1998 penta 5.7 and this past weekend my power steering pump locked up,bone dry.i have read where the power steering cooler is the usual culprit.what i did was take it out and used an air gun to pressurize it under water but i did not see any air bubbles at all come out the water side.i did notice the small sheen of oil when it is in the lake that i have read about but thought it was from me greasing outdrive.i dont have 1/2 quart of oil in bilge from an inside leak and i trailer it every week i thought i would notice it when i pull plug.my question is ,is there a better way to test it or just replace the pump and keep a close eye on the fluid level.is there any other place it could be going?thanks in advance for your time