Trailer Maintenance checks

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Kick the Tyres

You’re stuck on the side of the road… the middle of nowhere. You’ve lost both wheels on one side of your trailer and your boat has just missed becoming a right-off! Think it won’t happen to you… think again…

Basic trailer maintenance is essential for all boaties. While reams of information on this exist, here’s a reminder of key points … especially if you’re soon to be laying up your boat for the winter.

Washing your trailer

Washing your trailer after salt-water use is always a good idea – regardless of whether steel, galvanised, or alloy. This is because salt water is an electrolyte solution containing more dissolved ions than freshwater… this enables electrons to move more easily and bring forward corrosion more quickly in salt water than it does in fresh water. If your trailer has a box section construction, pay particular attention to rinsing the internal cavities as well.

A trailer washing system fitted to your trailer such as ‘Spitwash’ can significantly assist this rinsing process, while also facilitating consistent and efficient water jetting onto to critical components.

Your brakes

Braked trailers have either a cable or hydraulic braking system. Cable brakes are simple to maintain and a good squirt of a lubricant on the mechanisms after each trailer use, plus a periodic greasing of the tow-ball piston will often suffice. But note that the brake cables stretch over time and we regularly come across trailers with little or no braking – some owners admit they’ve never adjusted the brakes. Please check and re-tension the cables regularly.

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Hydraulic brakes are more efficient and apply significantly more braking force. These systems are more suited to heavier braked trailers – perhaps 2ton and above. Many people have been challenged and frustrated by brake calliper pistons locking up. When this occurs in callipers using phenolic plastic pistons (looks like a like a brown bakelite) – lockup is caused by the piston swelling and then seizing in the calliper cylinders.

A change to stainless steel pistons would be appropriate or we suggest you seek trailers where stainless steel pistons and cylinders used in the brake callipers are included in the standard build.

Hydraulics brake systems require the brake fluid level to be maintained. Be sure not to let the level fall too low otherwise there is a chance that air can enter the brake circuit and brakes will not be effective again without being re-bled.

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Check your brake pad wear – if you use your trailer regularly and travel significant distances, then a trailer fitted with stainless steel brake discs will be much friendlier to your brake pads. This is because the corroded and rusty surface of steel discs wears your brake pads many times faster.


A set of good quality submersible trailer lights is so convenient. But many people are concerned about water ingress despite many advances in technology – especially LED. Lights that haven’t leaked after a first few immersions are unlikely to be leakers!

Assuming the electrical wires are in reasonable condition and do not have exposed wire connections, the part of lights needing the most attention and regular checking are the trailer plug and tow-ball light socket. This electrical interface needs to be free of damage, dirt, and grime and a regular squirt of CRC and a brush with an old toothbrush will be sufficient to maintain good contact.

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Nuts and bolts check

Boat trailers travelling at 100km/h over bouncy roads suffer many induced stresses in key components through flexing movement. And movement can cause the loosening of nuts and bolts. And all trailers use bolts and nuts to fasten critical items such as wheels, axles, leaf springs, etc. On a regular basis, any critical nuts and bolts should be checked – and nothing is more important than to make sure your trailer wheel nuts are properly tightened.

Winch and Webbing or rope

Winches are used as one of the primary devices to secure the boat to the trailer during travelling, launching, and retrieving. A regular check of the entire length of spooling rope or webbing is absolutely necessary, and any fraying or wear and tear observed must be repaired at the earliest opportunity.


One maintenance item stands out above all others…. Your wheel bearings. When there is an unexpected failure, you’re likely to have run out of options. While others may repair or service your wheel bearings, every boatie needs to self-inform what is inside the wheel hub, how much grease is there, what grease needs to be used, and what seals are used. Boaties are encouraged to check bearings yearly, and some even 6-monthly.

There are other factors but the most important is the bearing lubrication. Do not rely on your Bearing Buddy to grease your bearings properly!

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The best-bearing performance and longevity come from neither too much nor too little grease. Too much grease packed next to the bearing race causes heat to be induced and can lead to degradation of the lubricant, making it more susceptible to breakdown. Too little grease has the same effect except that damage is caused here by friction… also resulting in heat. And when a wheel hub, heated by hotter bearings, is quickly cooled when it enters cold water, then the bearing seals will be in danger of allowing water to enter the wheel hub chamber.

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