Hydraulic actuators (or surge brakes) are a popular braking system in the rental industry. By confining the braking system to the trailer it allows the rental customer to tow trailers and equipment without installing expensive devises or controllers normally needed for electric brakes. However, since it is a self-contained system, good maintenance and upkeep is vital to safe and reliable operation. The key to successful and lasting operation of the surge brake unit is to keep the master cylinder free of contamination and always maintain proper levels of brake fluid, says Lancaster.
"Inspect the master cylinder for proper fluid level and use only DOT-3 or DOT-4 brake fluid from a sealed container," he notes. "Improper fluid level is one of the most common causes of hydraulic brake failure but also the most easy to prevent. If the fluid gets too low, or goes empty, you will have to bleed the complete brake fluid system. This is not an easy task and might never have to be done under normal operating conditions. Refer to the manufacturer's owners manual for fluid requirements."
Lights and wiring can be damaged by road salt, debris, age, etc. Wiring issues can be as simple as a light not working or as extreme as having no brakes. The wiring system should be inspected, repaired or replaced as needed.
Make sure connector-plug prongs and receptacles, lightbulb sockets, wire splices and ground connections are clean and shielded from moisture. Lightly coat all electrical terminal connections with nonconducting (dielectric), light waterproof grease.
Clean the prongs with very fine sandpaper, being careful not to damage the contact area. And clean the surface deposits in the connector holes. (Make sure the lights are off to prevent blowing a fuse.) Clean off only the deposits and lubricate lighting with dielectric, light waterproof grease.
Hitch and coupler. Check the nuts, bolts and other fasteners to ensure that the hitch remains secured to the tow vehicle and the coupler remains secured to the trailer. The connection point might require periodic lubrication to permit free movement of the coupler to the hitch ball. The coupler is the main securing component to the tow vehicle. It's the only thing holding the trailer and cargo to the vehicle. It should be the right size and capacity for the job.
Every trailer is unique, so be sure to check your specific owner's manual for the proper maintenance of your particular trailer.
The hub bearings require grease on a regular basis. "This is often one of the most overlooked items and simplest to maintain," says Lancaster. Failure to maintain greased bearings can cause the hub and axle to seize — which means the wheel and tire won't rotate.
Several suppliers offer hydraulic load and lift trailers to the rental industry. "These types of trailers need to be maintained on a more regular basis, because they have more moving parts in addition to a complete hydraulic system," says Knudsen.
The hydraulic system oil level should be checked at least once a month, if not more often. The oil should be inspected for moisture and changed, along with the filter (if there is one), if any moisture is detected. The hinge or pivot points should be lubricated and checked for wear or cracking as well as any other mounting points.
The final word
Trailers are some of the most overlooked and abused pieces of equipment in a rental fleet. Customers don't always operate trailers carefully and often overload the unit. To make sure your customers continue to have a safe, productive rental, scheduled maintenance for your trailers is a must.
"Often rental businesses have more invested in the equipment on the trailer than in the trailer itself," says Jeff Ford with JLG Industries Inc. "Trailers might not be a tool to get a job done, but they're a necessary component to get the tool to the job, so don't forget the trailer."
Additional information for this article was provided by bil-jax, JLG Industries Inc., Towmaster Trailers and the National Highway Traffic Safety Administration, www.nhtsa.dot.gov.