Since the function your trailer performs is based largely on its tires, it's a good idea to keep your trailer tires well maintained. In many cases, especially with large trailers, the added weight the tires support even when stationary can cause trailer tires to wear out significantly faster than the tires on your coach vehicle.
If your trailer's been sitting around unused for a while, it's a good bet the tires could use inflating. Using your trailer often can obviously lead to loss of air pressure, but tires also lose pressure when not in use. All tires leak air over time, and so keeping an eye on your air pressure is essential to keeping your trailer properly maintained.
The reason for maintaining proper air pressure in your tires is simple: Taking a trailer fully loaded out on the open road with under inflated tires is extremely dangerous. The friction created when the rubber meets the road can cause degradation of your tires. This situation can lead to a blow out, which is the last thing you want to happen to a trailer hitched to your car and traveling at high speeds. Even if a blow out doesn't occur, improperly inflated tires flatten under the strain of an overly heavy load. This can create another dangerous situation, one where swaying of the trailer can occur.
Before inflating your tires, check the manufacturer's suggested pounds per square inch (psi) of inflation. It should be listed in the owner's manual for your trailer. You should also note if your trailer's tires call for a high psi when carrying heavy loads. If so, be sure to observe this when you inflate your trailer tires.
Before every trip, check your trailer tires for wear. It's recommended that you replace your trailer tires every three to five years. When replacing tires, make sure the ones you purchase match the ones you already have, if you're not buying a complete set. It's a good idea to shell out the extra cash to replace all of your trailer tires at once, as even good tires are worn to some extent and the addition of a new, unworn tire can lead to handling difficulty when towing. Some manufacturers make tires that are specially designed for trailers. Bias ply tires are stiffer than the radial tires found on most cars and trucks. This stiffness helps to protect against sway, since the tires don't give from side to side as much as more pliable auto tires can. When you store your trailer, drape tarps over them to protect against sun damage, which can cause cracking and splitting.
Okay, you've gone ahead and spent the money to replace your trailer's tires. You've got them properly inflated and you're good to go. Your trailer's almost back to mint condition. Read the next page about checking your trailer's light systems.