Hi, my friend just bought a brand new bayliner with a mercruiser drive. The tilt/trim was working fine when we were out on the boat but when we got back and went to lower outdrive the pump was working but would not lower. Brought it to dealer and they bled it out but after getting home and testing a couple of times it again stopped working. Anything obvious we should be looking for ? The fluid is topped off and the pump does run .The motor has about 4 hrs. on it. Thanks.