One of the most common questions we hear at Trailer Parts Unlimited is:
“How do I know if I installed my trailer brake axle the right way so the brakes aren’t backwards?”
It’s a great question—because installing a brake axle backwards can cause serious performance and safety issues. Here’s the simple way to double-check your work.
Check the Brake Wires
The easiest way to confirm your trailer brake axle is installed correctly is to look at the brake wires.
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The wires should face toward the back of the trailer.
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If the wires are pointing forward, the axle is likely flipped the wrong way.
Look for Left & Right Labels
Many brake backing plates come with small stickers that say “Left” and “Right.”
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Left = Driver Side (same side as when you’re sitting in your truck).
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Right = Passenger Side.
Keep in mind—these stickers aren’t always there, so don’t rely on them 100%.
Quick Rule of Thumb
If you don’t see stickers, just remember this rule:
Brake wires face the rear of the trailer.
That’s the easiest way to make sure your trailer brake axle is set up correctly and ready to go.
Shop Trailer Brake Axles With Confidence
At Trailer Parts Unlimited, we stock brake axles, idler axles, hubs, drums, brake assemblies, and suspension kits—all designed to get your trailer on the road safely and reliably.
Shop now at TrailerPartsUnlimited.com – or stop by our store in Huntsville, TX (Exit 118 off I-45, next to Pilot and Chicken Express).
Remember: The price you see is the price you pay—no hidden tariff fees, no pickup fees, just honest business.