Mercury trim and tilt problem

[BoatingIsNewToUs]

Recently bought a 1979 4 winns boat with a 115 hp mercury with power trim.
Fixed everthing up and our last time out the trim stuck in the up position.
Have tried re bleeding the lines but the down lines will not pump oil, the up lines pump a good stream of oil.

Any ideas on what to do?

 

[Wingedwheel]

Re: Mercury trim and tilt problem

Does the pump run when you try to lower the outboard?

 

[Blevins]

Re: Mercury trim and tilt problem

You may have air in the line try toggling the up and down quickly to try and work the air out. Then refill with oil. If the situation does not correct itself then on the port side of the trim cylinder there should be a screw or plastic nut...that is the manual release you may need to release it down and be easy on the trim until you are certain it is air free. Also I'm sorry to say this but I actually stopped to help a guy this happened to. He was drifting and tilted his motor up when he did this his swing arm that keeps the motor from going down swung down and he could figure out why his motor wouldn't trim down. Sorry I hope that's not it but I had to say it.

 

[Chris1956]

Re: Mercury trim and tilt problem

Do you have the year of the motor? The PTT units are different for different years. It sounds like you have the two trim cylinders on the motor and the trim pump and resevoir in the boat. if that is the case and you see no oil from the pump when the motor is running in the down direction, it is likely the check valve has failed.