I have a 85 chaperral 187xl with a 3.8l chevy and a stringer 800 sterndrive. I changed the oil in the engine and after the service i hooked it up to the muffs and ran it for a till worm up. I was in the boat and had my son turn the hose on. Not knowing that he turned it on all the way till it stoped is it possible to over pressure the outdrive and get water in the upper and lower gear case. the upper was milkey but when i pulled the plug on the lower it was frash clear water. what should i do i am going to change the water pump. should i change the fluid and put it in the water and see what happens? thanks in advance all help is greatfull