Wash your trailer with warm water. Note that most trailers are finished off with several coats of auto paint and sealant, so use soap that is specially formulated to be gentle on auto finishes. Use a regular hose instead of anything high-powered. Remember to wash and rinse underneath your utility trailer, too. A boat trailer will need a washing every time it's used, especially if it's been in saltwater. Finish up by cleaning the smaller details of your trailer, like the license plate and lights.
Look for rusted parts when your trailer is fully dry. Sand away these patches with sandpaper or steel wool. Touch up these areas with rustproof paint. Wait for the paint to dry. Then apply a healthy coat of wax on your trailer's freshly painted metal parts. Keep your trailer waxed on a regular basis after that. Doing this will protect the metal parts of it from the elements and will prevent rusting. Touch it up, even if it's just a small thing, because it can always build over time.
Keep up with your trailer's mechanical parts by greasing up the joints and axles. Do some greasing, especially before taking it back onto the road. Dirt is your trailer's biggest enemy, as it causes friction and breakdown. Lubricate features like the winch, ball hitch, springs and tongue jack. One of the most important parts to grease are the wheel bearings, the cylindrical rings that connect the wheel to the axle and allow the trailer wheel to freely rotate.
Inflate your tires, especially if your utility trailer has been sitting around for some time. Check the manufacturer's suggested pounds per square inch (psi) of inflation. It should be listed in the owner's manual for your trailer. Also, check your tires for wear and tear because they might need to be replaced, too. Add the proper amount of air into your tires at a local air pump. Note that driving with deflated tires is dangerous and could lead to a blowout.
