Power Trim Boat Maintenance: Adding Oil The Right Way

Power trim motors are an essential component of a boat's functionality, and regular maintenance is required to keep them in good working order. The process of adding oil to the power trim can vary depending on the boat's specific model and the type of oil being used. It is important to consult the owner's manual or seek advice from experienced boaters to ensure the correct procedure is followed. The oil used can range from standard hydraulic fluid to specific power trim oils, and even transmission fluid or power steering fluid in some cases.

How to put oil in a power trim boat

What type of oil to use

When it comes to the type of oil to use for your power trim boat, there are a few options available, and the choice depends on the specific requirements of your boat's trim system and your personal preferences. Here is a detailed guide to help you choose the right oil:

Types of Oil for Power Trim Boats

• Mercury Power Trim Oil: Mercury manufactures a specific power trim oil that is readily available at most marinas. This oil is designed to meet the requirements of Mercury boat engines and can be a reliable choice if your boat uses a Mercury motor.
• Motor Oil: Some boat owners prefer to use standard motor oil for their trim systems. The recommended viscosity for this option is often 10W30, 20 or 30 weight non-detergent motor oil. Using a thinner viscosity motor oil can make your trim pumps work faster.
• Transmission Fluid (ATF): Automatic transmission fluid (ATF) is another common choice for power trim boats. It is available at affordable prices, and some users find that it provides better accuracy during trimming due to its slightly thicker consistency.
• Hydraulic Fluid: Regular hydraulic fluid can also be used for power trim systems. It is important to note that hydraulic fluid varies in foaming characteristics, but this is typically not an issue for tilt and trim applications.
• Power Trim and Steering Fluid: There are specific fluids marketed as power trim and steering fluids. These are designed for maximum pump and seal life and often contain special anti-wear and anti-foam additives, as well as corrosion inhibitors.

Additional Considerations

When choosing the type of oil to use, it is essential to refer to your boat's user manual. The manual will provide specific recommendations for the type of oil that is suitable for your boat's trim system. Additionally, always purchase high-quality oil from reputable brands to ensure the longevity and optimal performance of your boat's trim system.

How to add oil to the trim motor

Step 1: Prepare the Boat

Before you begin, ensure the boat is on land, with its bow facing downwards. This will level the trim motor's reservoir.

Step 2: Locate the Reservoir

The trim motor's reservoir is located between the uprights of the engine mounting bracket. It will be at the same negative 13- to 15-degree angle as the transom.

Step 3: Prepare the Engine

Tilt the outboard engine up and put the support bracket in place to prevent it from falling. This is essential for your safety.

Step 4: Remove the Fill Cap

The fill cap is a hex-headed or slotted screw on top of the hydraulic reservoir. Remove this with the appropriate tool.

Step 5: Fill the Reservoir

Using a syringe or pump, add oil to the reservoir until it is full. Fill it until oil starts to come out.

Step 6: Bleed Air from the System

Tilt the engine up and down several times to bleed air from the system. Check the fluid level and add more fluid if necessary. Repeat this process as needed.

Step 7: Reinstall the Fill Cap

Once the reservoir is full and the air has been bled from the system, reinstall the fill cap.

Step 8: Check for Leaks

Topping off the fluid may only be a temporary fix. Check for any leaks and, if necessary, take your engine to a professional for repair.

Oil Type

It is important to use the correct type of oil for your trim motor. Some sources recommend using a specific power trim oil, while others suggest straight 30W or 10W30 motor oil. It is also possible to use transmission fluid or power steering fluid, but check your owner's manual or the manufacturer's recommendations for the best type of oil for your boat.

How to grease the tilt tube

To grease the tilt tube of your boat's engine, you'll need to locate the tilt tube itself, which can be found at the front of the engine, where it connects to the transom. Once you've found the tilt tube, follow these steps:

• Get your hands on a grease gun loaded with waterproof marine grease.
• Apply a generous amount of grease to the grease fittings on the tilt tube using the grease gun.
• Stop squeezing the grease gun when you see new grease pushing out old grease from the fittings.
• Wipe off any excess grease with a clean cloth or rag.

It is recommended to use a marine grease designed for outboard motors, such as Quicksilver® 2-4-C, as it acts as a lubricant and a moisture barrier, protecting the engine's moving parts from water damage.

Additionally, remember to always deploy the tilt support bracket when your boat is docked or moored with the engine tilted up. This inhibits corrosion and fouling on the rams.

How to bleed the lines

Bleeding the lines of your power trim boat is a crucial step to ensure the proper functioning of the trim-and-tilt system. Here's a detailed guide on how to effectively bleed the lines:

Prepare the Boat:

Before initiating the bleeding process, it's essential to prepare your boat. Park your boat on land and ensure that it's in a bow-down attitude, levelling the reservoir. This is important because the reservoir is located at the waterline, and you want to ensure it's easily accessible and not submerged.

Locate the Hydraulic Reservoir:

The hydraulic reservoir is typically a cylindrical component situated between the uprights of the engine mounting bracket. It's positioned at the same negative 13- to 15-degree angle as the transom. To access it, you might need to crank down the trailer's tongue jack or borrow a trailer if you don't have one.

Tilt Up the Outboard and Secure It:

For safety reasons, always use the tilt support bracket to secure the boat's engine. Tilt the engine all the way up and deploy the support bracket. Then, trim the engine down until it rests comfortably on the support. This step is crucial to prevent any accidental engine movement, which can be hazardous.

Remove the Fill Cap and Fill with Fluid:

Once the engine is securely tilted and supported, locate the fill cap on top of the hydraulic reservoir. It's usually a hex-headed or slotted screw. Remove this screw carefully and begin filling the reservoir with the appropriate hydraulic fluid. Fill it to just overflowing, and don't forget to wipe off any excess fluid.

Tilt the Engine to Bleed Air:

After filling the reservoir, it's time to bleed the air from the system. Tilt the engine up and down several times. This action helps to remove any trapped air bubbles in the lines. You may need to repeat this step a few times until you no longer see any air bubbles and the fluid level remains consistent.

Reinstall the Fill Cap and Check Fluid Level:

Once you've bled the air and are satisfied that there are no more air bubbles, reinstall the fill cap securely. Recheck the fluid level and top it off if necessary. It's important to ensure that the fluid level is correct to maintain the proper functioning of the trim-and-tilt system.

Repeat as Needed:

In some cases, you may need to repeat the entire process a few times to ensure that all air is removed from the lines. Each time, fill the reservoir, tilt the engine, and check the fluid level. Additionally, pay attention to any changes in the sound of the pump, as this can indicate that the air has been successfully removed.

Additional Tips:

• Always refer to your boat's manual for specific instructions and fluid recommendations.
• When working with hydraulic fluid, wear protective gear, and be cautious of any spills or leaks.
• If you notice a leak or if the fluid level consistently drops, consider taking your boat to a professional for further inspection and repairs.

How to check if the reservoir is full

Checking if the reservoir on your power trim boat is full is a relatively simple process. The reservoir is usually located near the back of the boat engine. It is a cylindrical container found between the uprights of the engine mounting bracket.

To check the fluid level, start by locating the dipstick on the side of the engine. It usually has a yellow handle. Clean the dipstick with a rag or paper towel, then insert it into the fill hole and pull it out again. Check the fluid level on the dipstick. If it's below the "full" line, you'll need to add more fluid.

Another way to check is by removing the fill cap or screw from the reservoir. On some boats, this may be a hex-headed or slotted screw, while on others, it may be a plastic oring-sealed plug. Once the cap or screw is removed, you can visually inspect the fluid level inside the reservoir. If the fluid is below the fill hole or the top of the reservoir, you will need to add more.

It is important to note that the boat should be on land and positioned with the bow down to level the reservoir, which is at the same negative 13- to 15-degree angle as the transom. This can be achieved by cranking down the trailer's tongue jack.

Additionally, before checking the fluid level, it is recommended to tilt the engine all the way up and deploy the support bracket to prevent the engine from accidentally falling and causing injury.

Frequently asked questions