Mercury 1989 90hp Power Tilt Leaks Down

[crkranz]

My dad was going to give me his 90hp motor to put on my boat this winter. Unfortunately this boat was just rear-end as he was driving back from the lake the other day and did some damage to this motor. The power tilt seems to work fine, but very slowly leaks down if the motor is left tilted up. Any ideas on what the likely problem is or how do I go about trouble shooting this? Can I do this with the motor on the boat or do I have to pull it off?

Thanks for your help.

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

Can you visually see where the fluid is leaking from? Tilt the motor all the way up, wipe it completely down. then determine where its coming from. If it is just the seals at the tilt and trim rams you can fix with relative ease. You might have a crack somewhere in the manifold.

 

[crkranz]

Re: Mercury 1989 90hp Power Tilt Leaks Down

I don't believe it is leaking any fluid externally. I will do the wipe down and double check.

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

if your not finding any fluid, you have a crack internally.

 

[crkranz]

Re: Mercury 1989 90hp Power Tilt Leaks Down

if your not finding any fluid, you have a crack internally.

Any idea on what component is most likely to crack or where to look first?

 

[snowbrd84]

Re: Mercury 1989 90hp Power Tilt Leaks Down

I had to pull my boat back out of the water real quick when launching last month and forgot to trim up the motor. It dragged a little on the way out but everything seemed to work fine after... However, just like yours, it very slowly leaks down now without dripping any fluid. I havent had time to look at it, but hoping there is a "simple" fix... Ill post back if i figure it out this weekend...

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

you wrote the was a impact, where did it impact.

 

[crkranz]

Re: Mercury 1989 90hp Power Tilt Leaks Down

you wrote the was a impact, where did it impact.

He was sitting at a stoplight and a lady rearended him. He said the motor kind of slid up her hood. The prop is dented a little and skag is busted off.

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

Well you probably don't have a crack, I am leaning towards a blown seal.

 

[Faztbullet]

Re: Mercury 1989 90hp Power Tilt Leaks Down

The impact valve in tilt cylinder has not reseated....

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

Faztbullet nice call
Impact relief valves not seating in trim ram.
Lower check valve not seating in port side trim ram.
Upper check valve not seating in port side trim ram

 

[crkranz]

Re: Mercury 1989 90hp Power Tilt Leaks Down

Thanks for the ideas, I appreciate all your help. It gives me a idea on where to start. Hope I can fix it myself. I think he has the factory service manual, is the hyd tilt unit covered in the manual? I have never worked on one and have no idea what is involved. Do I have to pull the motor off the boat?

 

[hall832]

Re: Mercury 1989 90hp Power Tilt Leaks Down

the Mercury service manual covers the Trim Tilt assembly.