For optimum trailer brakes everything in the trailer brake system must be in proper working order. If you own a travel trailer, 5th wheel trailer or other towable RV it is important that you perform routine maintenance on the the trailer brake system. Intervals for trailer brake and wheel bearing inspections vary depending on the axle manufacturer. If you don’t have the trailer axle manual a general guideline for inspection intervals is annually or every 5,000 miles. This routine inspection should include trailer brake linings, brake wiring, brake drums, brake springs & mounting hardware, brake magnets, wheel bearings and races and seals.
Important Note: If you are not comfortable performing this type of maintenance on your trailer have the inspection/work done by an authorized RV repair facility.
Caution: Before removing any tires/wheels to work on the trailer brakes certain safety procedures must be followed. The trailer needs to be parked on a hard flat level surface. The tires on the opposite side you plan to work on must be chocked (front & rear) to prevent any possible movement forward or backward. The trailer must be jacked up according to manufacturer instructions and properly rated jack stands installed to support the trailer’s weight while the work is being performed. Never go under a trailer that is not properly supported by jack stands.
5,000 mile/annual inspection:
Brake Linings:
brake lining
Inspect the brake linings for wear and any contamination that can affect the operation of the brakes. It’s not uncommon to see oil, grease and other contaminants on the brake linings. As brake linings wear and/or are contaminated the braking force diminishes. Inspect the brake linings for cracking (typically caused by excessive heat from braking) or excessive wear. If the linings are only 1/8 inch thick they should be replaced.
Brake Adjustments: As the brake linings begin to wear the brake actuating lever must travel further to apply the same braking force against the drums. Eventually the brake linings cannot effectively reach the drums and manually adjusted brakes need to be adjusted. This requires a brake adjusting tool and proper clearances from the manufacturer. It’s probably best left to the professionals.
Brake Drums:
brake drum
Inspect the brake drums for excessive wear and scoring or grooves that may affect the operation of the brakes and damage brake linings. If you are not sure about the amount of wear, or if it looks like the brake drums were exposed to extreme heat have the drums inspected by a machine shop or brake specialist.
Brake Springs & Hardware:
brake hardware
Inspect the brake return springs and brake mounting hardware for proper mounting and operation. Replace any damaged or defective parts.
Brake Magnets:
brake magnet
Inspect the brake magnets for wear. If excessive wear is evident (i.e., windings can be seen through the surface) the magnet needs to be replaced. Inspect the brake magnet wiring for wear and good connections. Repair the wiring as required.
Wheel Bearings, Races & Seals:
wheel bearings
Another common problem with trailers is lack of wheel bearing maintenance. Wheel bearings need to be inspected for damage and proper lubrication. Seals and wheel bearing races need to be inspected for damage. If the wheel bearing grease is old or insufficient the bearings need to be thoroughly cleaned and repacked. If you are not familiar with how to properly repack wheel bearings have the work done by a qualified repair facility.
Axle, Springs and Suspension Components: When the tires are removed from the trailer it’s a good time to inspect suspension components. Look for any loose or damaged mounting hardware and for any broken or cracked welds. Have any damage repaired prior to using the trailer.
Battery Maintenance: Don’t forget to include routine battery maintenance too. The trailer break-away switch will not operate if the auxiliary battery is not connected or properly charged.
When you reinstall the tires torque the lug nuts to manufacturer specifications.
Trailer Pre-Trip Checks
All too often a trailer sits for periods of time not being used. Many times this non-use is for extended periods of time. When it’s time to use the trailer we tend to hook it up and drive off without really considering what may have gone wrong while it sat in storage. It’s quite common for a battery to discharge, for tires to be dangerously low on air, and the trailer plug contacts to get dirty and corroded. If the trailer brakes don’t work properly because of a bad contact in the plug, or a tire fails because of under inflation it puts us and others in harm’s way.
To help prevent these types of things from happening I want to include a simple pre-trip trailer checklist you can follow to make sure your trailer is ready to hit the road. After properly hitching the trailer (i.e. WDH adjustments, sway control, safety chains) to the vehicle make the following checks:
- Inspect the trailer plug and vehicle receptacle contacts for dirt, debris and corrosion. Clean the plug and contacts as required, ensuring a proper connection. Plug the cord in and test all trailer lights.
- Connect the trailer break-away lanyard to a secure connection on the tow vehicle.
- Test the operation of the trailer brakes. Remove any wheel chocks. Pull the trailer forward slightly and depress the brake pedal to verify the trailer brakes are engaging. Test the brake controller manual override for proper operation.
- Check all tires for abnormal wear and any weather cracking/checking. If any cracks in the tire sidewalls are deeper than 1/32” have the tire inspected by a professional before towing the trailer.
- Check and adjust tire pressure in accordance with the federal certification label on the trailer or using the tire manufacturer load and inflation tables.
- Check the condition of the battery. Check the water level in each cell and add distilled water as required.
- Check the battery state of charge with a multimeter or battery hydrometer. If you don’t feel comfortable working on or around lead acid battery’s have battery maintenance performed by an authorized service center.
- Every 3,000 mile or annually schedule a trailer brake and wheel bearing inspection.
A little trailer brake and wheel maintenance goes a long way. Now you won’t be the guy you always see broke down on the side of the road. To learn more about maintaining your RV visit www.rveducation101.com
Have a great camping season,
Mark Polk
Mark Polk
RV 101® / RV Education 101® 
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