MOBILE OUTBOARD MECHANIC

Why isn't my power trim working?

- What to do if your outboard power trim unit stops working
- How to avoid power trim problems

Outboard power trim units use a 12 volt electric motor to drive a small hydraulic pump which pumps oil through a series of valves and cylinders to lift the outboard up and down.

Outboard power trim units are items that commonly have problems.

The brushes inside the electric motor get worn out.

The cover on the electric motor is made from mild steel and then submerged in salt water so they often rust away and allow salt water into the electric motor and cause it to fail.

The rams often corrode or get chatter marks on them and that causes the seals to fail and the hydraulic oil to leak out.

The switches and electrical relays often fail. Electrical diagnosis is required for this.

What to do if your outboard power trim unit stops working:

The most important thing you need to do is understand how to operate the manual release valve.

The manual release valve allows bypassing of the pump and motor so you can lift the outboard up to get it on the trailer at the boat ramp or to get it down while at the reef for example.

It is best to familiarise yourself with this step while the boat is at home in the garage.

Access to the manual release valve is located on the side of the large clamp bracket that bolts to the transom of the boat. There is usually a little picture of an outboard moulded into the clamp bracket.

A large flat blade screwdriver is required to turn the valve anti-clockwise to loosen.

These manual release valves are often seized and useless unless they are regularly activated and lubricated.

Once the valve is loosened, the outboard will drop down so be careful where your fingers are.

The outboard can be lifted up but it won’t lift up quickly as you are squeezing a lot of oil through a small passage. Keep holding upward pressure.

Once the outboard is lifted up, the tilt locks should be applied to keep it in the up position.

If the power trim stopped working because all the hydraulic oil leaked out, the reservoir can be refilled in the up position. With the outboard up, the fill plug should be visible.

Automatic transmission fluid is used in most applications and is filled to the bottom of the fill plug.

Bleeding of the power trim unit is achieved by trimming the outboard up and down several times and topping up the fluid as required.

How to avoid power trim problems:

Protect the power trim unit from the harsh salty environment.

Always tilt the outboard up when you return from salt water use and wash the entire power trim area with plenty of fresh water.

Spray the entire power trim unit with lanolin every time you return from salt water use.

Spray the power trim motor casing with a heavy duty rust preventative such as Tectyl 506 on a regular basis to keep it thoroughly covered.

Check the condition of the power trim unit seals and get them replaced as required.

Regularly check the level of power trim fluid and keep it topped up.

Regularly activate and lubricate the manual release valve.

- Contact Cairns Outboard Service for your outboard service requirements.

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