Trim Leaks Down

[Larry (Bo) Bolander]

I have a "94" 115 Mercury motor. My motor won't stay up. I tried trimming it up and down a few times to purge the air out, didn't work.

I noticed a small leak in the filler plug. Going to buy a new one today.

Is there a torque specification for the filler plug?

Any other solutions or do I need to buy a new tilt and trim unit? (It's the early version with the black filler plug)

 

[zman]

There’s a Oring gasket that might be bad on that plug

 

[Larry (Bo) Bolander]

Finally got a new plug. While I was there, I bought a new release valve plug.
Naturally I lost all the fluid when I took the plug out.

Dropped the bow of the boat/trailer all the way to the ground to get maximum amount of fluid back in the tilt/trim unit.

Had the motor up as far as it would go.
Couldn't get near as much fluid in as what came out.

Anyway, got as much fluid in as possible, tightened both plugs and now the motor won't go up or down.

Where did I go wrong?

 

[jerry shack]

You still got air in the pump. Run the trim and keep opening the fill plug to get the air out and keep adding fluid. Some times you will have to help the motor up by hand while running the pump motor. That's a good time to add fluid get a board or something to support the motor from falling down .

 

[Larry (Bo) Bolander]

I tried to raise the motor but, it wouldn't move at all. I tried lifting it but, with my bad back, it was a no go.

I finally gave up and took it to my local boat marina. They said the tilt/trim unit was bad, needed to be replaced. ( of course it did)

$1400.00 for a new tilt/trim!! I replaced one myself several years ago, parts were $700.00. Has the cost gone up that much or am I getting reamed?

 

[jerry shack]

I checked and the price of a new unit from Mercury is $1,107.84 Possibly the $1400.00 that included the install also. However I did find some other units a lot cheaper but not new.

 

[Old Outlaw]

I checked and the price of a new unit from Mercury is $1,107.84 Possibly the $1400.00 that included the install also. However I did find some other units a lot cheaper but not new.

Most hydraulic cylinders can be rebuilt. Around at some of the shops that do that sort of thing.

 

[Charleesdad]

Having the same issue with an ‘85 Mariner magnum 150. No oil on the ground. Trimmed up and set on the stop; added QS trim and steering fluid. Trimmed up/down a few times. Checked again. Still full. Still falling. Any help appreciated.

 

[Finman55]

Here’s my experience with trim on a new Mercury 115, should have bought a Yamaha.
https://www.nitroowners.com/threads/2nd-time-to-change-out-115-trim-assembly.84951/

 

[Kirby Wilson]

The Trim/Tilt leaks off through the seals between the pistons and cylinders. These can be rebuilt. Most of the time they replace the unit due to the wear on the unit. Pumps can also go out.
When filling with hydraulic oil or oil, the unit has air trapped in the cylinders and reserve, that will require the trim to be raised and lowered a number of times. Even after this take it out and use it for a day the check and fill if necessary.
There should be a screw on the side of the unit to release the pressure while trying to raise the motor. Loosen the screw to raise or lower the motor, retighten the screw before taking pressure off of the motor or it will drop before you can tighten the screw.
Also when trimming the motor do not trim the unit to maximum height. The piston can come partially out of the cylinder causing damage to the seal and also can hang up the motor in full tilt sometimes. I have shaken the motor to get the piston back into the cylinder.
This is based on Mecury outboards.

 

[con70dor1]

The Trim/Tilt leaks off through the seals between the pistons and cylinders. These can be rebuilt. Most of the time they replace the unit due to the wear on the unit. Pumps can also go out.
When filling with hydraulic oil or oil, the unit has air trapped in the cylinders and reserve, that will require the trim to be raised and lowered a number of times. Even after this take it out and use it for a day the check and fill if necessary.
There should be a screw on the side of the unit to release the pressure while trying to raise the motor. Loosen the screw to raise or lower the motor, retighten the screw before taking pressure off of the motor or it will drop before you can tighten the screw.
Also when trimming the motor do not trim the unit to maximum height. The piston can come partially out of the cylinder causing damage to the seal and also can hang up the motor in full tilt sometimes. I have shaken the motor to get the piston back into the cylinder.
This is based on Mecury outboards.

Just did my 96 Honda 90, easy rebuild. Lots of Youtube help available. Kits available. 5star marine has parts and will rebuild them. A lot of tile and trim actuators are built by the same manufacturer and installed in a number of engines, including Merc and all the asian motors.