HYDRAULIC SYSTEMS

(Answers from page 22)

Many boats use hydraulics to activate and control different systems; mostly, we see hydraulics employed in steering systems, power trim and tilt, trim tabs, and outboard jack plates. On larger hulls, hydraulics actuate hatches, bow thrusters, davits, windlasses and stabilizers. Let’s take a look at hydraulics, how they’re used, and how you can maintain them.

—John Tiger

1. Your boat’s hydraulic steering system seems to be getting sloppier and less precise as the seasons go by. How should you tighten things up?

A. Check for fluid leaks from the helm unit back to the engine cylinder, and the hoses from the dash to the transom.

B. Add hydraulic fluid and bleed the system according to instructions.

C. Replace the entire system.

D. A and B

2. Your bass boat’s jack plate is operating erratically; when you raise it, the operation is slow and jittery. When you press the down button, the unit moves easier but still not like new. Where should you look first?

A. Check the plate and lift cylinder for binding; often there are fittings that should be greased, or plastic slide bearings that may be worn out.

B. The lift piston and cylinder may be leaking; check for obvious traces of fluid.

C. The electric motor/pump assembly may be leaking and needs fluid.

D. A and C

E. All of the above

3. Your outboard’s power trim system sometimes doesn’t work; you press the buttons for up and down and hear a clicking, but nothing happens. What might be the problem?

A. The connection from the relays (or solenoids) to the power trim electric motor is likely corroded and not continuous all the time. Start troubleshooting by wiggling the wires (blue and green) while a helper presses the trim and tilt buttons.

B. The electric motor is worn out, has a flat spot in the armature, or is corroded and on its way to failure.

C. The hydraulic pistons in the unit won’t move. Replace the unit.

D. A and B could both be correct.

4. Your boat’s hydraulic steering system is rated to handle engines up to 150 hp and boatspeeds up to 55 mph. Your engine is a 150, and the boat runs right at 50 mph. Your hull is rated for a 200 hp outboard, and you’re thinking about an upgrade. Your buddies say the steering system will be fine. Your dealer says it must be upgraded.

Who’s right and why?

A. Your buddies are right; the 50 extra horses and expected gain in speed won’t tax your present steering. After all, the designers anticipate that owners will overpower, so they always add a safety margin.

B. Your dealer is correct. The added 50 hp is beyond what the system is designed to handle; in addition, the expected speed gain will push the limits. Go for the upgrade.

C. Neither are correct; with that much power and speed, you should have a racing-quality system installed.

5. If your power trim system leaks, can you fix it with “weekend mechanic” tools and improvisation?

A. Not likely. Special spanner wrenches are required to remove the trim and tilt cylinder end caps. A service manual is key for understanding how the system works.

B. For sure; you can fabricate homemade tools or adapt existing ones to fit and replace all the seals and O-rings you find. They will work fine.

C. You will need to take a special class to service trim and tilt units.

6. Your sterndrive power trim and tilt cylinders are corroded. You keep your boat docked at a facility with dozens of other boats nearby. Upon inspection, you don’t see the same corrosion with the others. What could be the problem, and how do you solve it?

A. Your sacrificial anodes could be in need of replacement. Replace the anodes and the problem should abate.

B. Your corrosion may be due to your lack of pride in your boat.

C. The corrosion may be caused by interaction between your boat and another docked close by with a problem in its electrical system.

You may have to do some detective work or move to another slip.

D. A or C

1. D. A and B are the logical first steps. A system would have to be worn out indeed, or highly corroded, to warrant complete replacement before fixing leaks, adding fluid and rebleeding.

2. E. All of the answers could be correct and are easy to check.

3. D. A and B are both possible problems. Start by troubleshooting as described in A.

4. B. Your dealer is correct. While there is likely a safety margin built into the design, the system has limits for good reason. The helm, hoses and cylinder are not designed to handle the added pressure that 200 hp and 55-plus mph speeds will impart. In addition, should you ever be involved in an incident, you’ll want the steering system to be up to snuff to avoid any potential liability.

5. A is the most likely scenario. If you’re willing to invest in the tools and manual, you have a reasonable chance of fixing a power trim and tilt unit.

6. D. A or C are both possible causes of this corrosion. (Although B, lack of pride in your boat, could be a potential cause as well.)

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