Before the show season gets going full swing, now is a good time to do your horse trailer yearly safety check and service. If you aren't mechanical enough to do it yourself, a qualified professional can do all the work for you. If you are going to send it out for service you should know exactly what needs to be done so you can be sure that nothing gets overlooked. The local body shop or mechanic may not be familiar enough with horse trailers to be completely thorough unless you ask for specific tasks.
Before you take it to someone else, give it a good going over. For the safety of your horses, it is imperative that the floor is in perfect condition. Take out the mats and check the floor. If you have a wood floor, gently but firmly stick a knife into the surface and twist it. Do the same test from underneath. Rot can be hiding there where you can't see it. If the wood crumbles easily you may have to replace the floorboards. If you have an aluminum floor, check for corrosion or pitting. Also check the welds for stress fractures. If you see a potential problem with the aluminum, contact your dealer or manufacturer.
While you're underneath, look at the undercarriage. Any kind of rust or corrosion should be repaired immediately. Sometimes steel beams will have some surface rust that isn't much of a concern because it does not cause structural weakness, but ask an expert for an assessment. Cleaning surface rust off and repainting or undercoating the trailer can slow the rusting process. If you have an aluminum trailer, look for potential problems in the welds and joints where stress fractures can occur. A common source of potential problems in an all aluminum trailer is where the axles are attached to the frame. There should be a steel subframe that makes the transition to the aluminum frame. Check the bolt holes and fasteners for excess wear and loosening. Do the same where the coupler is attached to the frame.
All components of your suspension system should be visually inspected for signs of excess wear, elongation of bolt holes, and loosening of fasteners. Loose fasteners should be tightened or replaced. Worn spring-eye bushings, sagging springs, or broken springs should be replaced.
Examine the coupler for excess wear inside. Sometimes the coupler can wear enough inside to make the coupler fit too loosely on the trailer ball. The closure system should work perfectly. The coupler should be repaired or replaced if it is not working perfectly. Check safety chains and breakaway break system. Check or replace the breakaway brake battery. Is the jack working satisfactorily?
Look at each part of the hitch system. Does the ball size match the coupler size (2" or 2 5/6")? The hitch is only rated as strong as the weakest link. The rating on the ball, the slide in ball mount, and the hitch itself should meet or exceed the Gross Vehicle Weight Rating of your horse trailer. (There are two ratings on the hitch - weight carrying and weight distribution. The weight distribution rating is only valid when stabilizer bars are used) Check the welds and/or bolts where the hitch is attached to the tow vehicle.
Turn on the lights. Are all the lights and turn signals working properly? Replace bulbs as necessary. If they still don't work, have the wiring checked.
Look inside the trailer for any potential problems. Do all moving parts, doors, and latches work properly? Make sure all quick release functions are not frozen. If you have the rubber tire kind of mats that have wires in them, make sure the wires are not sticking out.
If you have any concerns, take the trailer to a trailer dealer, body shop, or other professional. Unless you are up to doing the job yourself, you will have to have such a professional check over and service the mechanical parts as well.
Wheels are a very important part of your running gear system. It is important that the wheels, tires, and axle are properly matched. Many bolt circle dimensions are available and some vary by so little that it might be possible to attach an improper wheel that does not match the axle hub. Make sure the wheel is matched to the axle hub and they have enough load-carrying capacity and pressure rating to match the maximum load of the tire and trailer. "Offset " refers to the relationship of the centerline of the tire to the hub face of the axle. Care should be taken to match any replacement wheel with the same offset wheel as originally equipped. Failure to match offset can result in reducing the load carrying capacity of your axle. If you have to replace a wheel, use only the approved rim contours in the tire manufacturer's catalog. The use of other rim contours is dangerous and could result in explosive separation of the tire and wheel and could cause a serious accident. Warning: Do not attempt to repair or modify a wheel. Even minor modifications can have a great effect.
Wheel nuts or bolts must be applied and maintained at the proper torque levels to prevent loose wheel, broken studs, and possible dangerous separation of wheels from the axle. Wheel nuts and bolts should be torqued before the first road use and after each wheel removal. Check and re-torque after the first 10 miles, 25 miles, and again at 50 miles. Check periodically thereafter.
The wheel hub must be removed to inspect the bearings and brake drums. Bearings must be cleaned or replaced and lubricated. If the axle is equipped with E-Z lube feature, the bearings can be periodically lubricated without removing the hubs from the axle, but bearings must still be inspected yearly.
Brakes drums must be inspected. The drum surface must be examined for excessive wear or heavy scoring. Depending on the amount of wear, the drums may have to be turned or replaced. For electric brakes, the armature surface should be refaced if it is scored or worn unevenly. The magnets should be replaced when the armature surface is refaced; the armature surface should be refaced when the magnets are replaced.
Electric brake lock up or grabbiness may be due to lack of synchronization between the tow vehicle and trailer brakes, too high a threshold voltage, or underadjusted brakes. Synchronization can be accomplished by setting the controller in the tow vehicle so the trailer brakes come on just slightly ahead of the tow vehicle brakes. Some brake controllers have a gain control that allows adjustment of the voltage that is applied to the brake system. It is important that the controller provide approximately 2 volts to the braking system when the brake pedal is first depressed and gradually increases the voltage to 12 volts as the brake pedal pressure is increased. If the controller jumps to a high voltage output, even during a gradual stop, the electric brakes will always fully energized and will result in a harsh brake and potential wheel lockup.
Brakes should be adjusted directly at the wheel itself after the first 200 miles of operation and at 3,000-mile intervals. For detailed instructions follow the brake manual included with your trailer.
Your trailer brakes must be cleaned and serviced at yearly intervals or more often as use and performance requires. Magnets and shoes must be changed when they become worn or scored. Brakes should be lubricated with a light film of Lubriplate or similar grease, or antiseize compound.
The most common electrical problem is low or no voltage and amperage at the brakes. The following are common causes of this condition: Poor electrical connections, open circuits, insufficient wire size, broken wires, blown fuses (fusing of brakes is not recommended), and improperly functioning controllers or resistors. Another common electrical problem is shorted or partially shorted circuits. Some of the possible causes are shorted magnet coils, defective controllers, bare wires contacting a grounded object.
Air and hydraulic brakes systems have very similar components, and maintenance is comparable to electric brakes. Some different kinds of problems would be air or vacuum leaks, hydraulic system leaks, air in brake lines, water or other impurity in brake fluid, or rusted or corroded master or wheel cylinders.
If your trailer has been stored for a while, check the tires for dry rot. More horse trailer tires wear out from rot rather than from road miles. The most common causes of sway and uneven tire wear are improper tire pressure or unequal tire pressure. Check that the tires are rated to carry the load. Note: the capacity and rating molded into the sidewall of the tire is not always the proper rating for the tire if used in a trailer application. Use the following guideline: LT and ST tires - use the capacity rating molded into the tire, Passenger car tires - use the capacity molded into the tire sidewall divided by 1.10.
Tire inflation pressure should be as recommended by the manufacturer for the load. Pressure should be checked cold before operation. Check inflation pressure weekly during use to insure maximum tire life and tread wear.
Before you put your horse in the trailer, make one final check to make sure wasps or other creatures have not made a home inside. You might also want to give the trailer a nice washing and wax the outside and inside, too. Aluminum trailers that do not have a painted or clear-coated finish can be given an acid bath. Be careful not to burn the aluminum.
Taking the time to make these yearly maintenance procedures will definitely increase your safety margin when you are on the road, and will add years to the life of your trailer.