Motor wont hold it's trim

[BrandonD]

I have a 1985 Mariner and the trim wont hold. Like if I trim it up it will go all the way up, but then just fall slowly all the way back down.

Will I have to replace the whole trim system or are there something less major I can try to see if it will fix it?

Thanks

 

[Barnacle_Bill]

Re: Motor wont hold it's trim

First check your manual release valve to be sure its tight.

 

[Fieldzy]

Re: Motor wont hold it's trim

Like bhile said, Check to see if the manual release Valve knob is tight, Also take a look in to see if there is any hydraulic fluid. If you can't see any in it then add some. If its full and you have tighten the Manual release Valve and it still won't hold, Check for leaks. Still does not hold.Then you may have air in there.

Good luck, Fieldzy

 

[BrandonD]

Re: Motor wont hold it's trim

I imagine the hydraulic fluid has not been added for many years. Is it normal to have to add that or does that mean there is a leak?

Thanks

 

[Chris1956]

Re: Motor wont hold it's trim

Brandon, A PTT unit can leak a bit, and still work fine. Fill and bleed your unit. The bleeding procedure depends on the type of system you have. The PTT units will use either Dextron III Auto trans fluid or 5W-30 motor oil. If the existing fluid is red, use the ATF. if it is brown use the motor oil.

If it still won't hold trim, you likely need a new piston seal. Look around for a replacement seal kit for your motor. If you have the two cylinder with teh boat mounted pump, you need a special tool to install the piston seal.

 

[BrandonD]

Re: Motor wont hold it's trim

I'll probably have to take the entire engine off the boat to do this sorta work huh?

Is that something I should even mess with or should I just take it in? It's a 175 hp engine so it's pretty big.

Thanks

 

[Chris1956]

Re: Motor wont hold it's trim

Brandon, I was able to work on my 150HP Johnny PTT unit without removing the motor from the boat. Your luck will depend on which PTT unit you have.