'99 Yamaha 90 HP

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: '99 Yamaha 90 HP

You don't drain and refill the tilt and trim fluid, only add some if necessary, and only if the system's seals have leaked. I've never had to add any fluid to the tilt and trim on my 1999 Yamaha 90C. It's a sealed hydraulic system and should stay that way. I believe folks use automatic transmission fluid when they do have to add any. I believe it's a good idea to maintain your tilt rams as clean and shiny as possible to reduce any wear on the rubber seals. Good Luck!
 

Louielizard

Recruit
Joined
Jul 25, 2009
Messages
3
Re: '99 Yamaha 90 HP

I don't think it's as simple as just adding it to it. You somehow must work the fluid in there and relieve all the air out. I want to know how it's done. Thanks.
 

dbarker

Cadet
Joined
May 23, 2010
Messages
6
Re: '99 Yamaha 90 HP

The system is self bleeding. Tilt the motor all the way up, fill the reservoir until fluid is level to bottom of fill hole. Normally it runs out a little bit. Put fill screw back in and operate tilt system up and down a few times to bleed out the air. I agree with last post you dont normally chage fluid out, just add some more of the appropiate fluid.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: '99 Yamaha 90 HP

If the fluid is contaminated and needs to be drained, you need to remove the whole unit and disassemble, clean, and reassemble replacing the things that need it. filling as you put back together. If you are just adding fluid the do a search for adding fluid and follow the steps. running the T&T motor while low will just airreate the fluid and cause problems from the foam
 

Louielizard

Recruit
Joined
Jul 25, 2009
Messages
3
Re: '99 Yamaha 90 HP

Thanks my man. Filling reservoir and cycling the piston a few times releases the air. Slow removal of the plug letting air and bubbly foam escape and adding more fluid did the trick. I wanted it drained thinking it may have been contaminated but just adding ATF did the trick. Thanks again to all responses.
 
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