Adjusting your trailer brakes is a crucial part of trailer maintenance that should be done every 3,000 miles or 3 months. Properly adjusted brakes are essential for safe towing and preventing wear on your tow vehicle brakes. But how tight should those trailer brakes be? Let’s take a look at some best practices for getting the right adjustment.
Finding the Sweet Spot
The goal when adjusting trailer brakes is to find the “sweet spot” – tight enough to sufficiently slow the trailer, but not so tight that the wheels lock up. Here are some signs you’ve hit the right adjustment:
- The tire still spins freely but has a slight scraping sound and added resistance.
- Dragging the trailer by hand takes noticeably more effort.
- The brake shoes or pads show even contact across the drum or rotor.
Adjust the brakes incrementally until you reach this point. Typically 2 to 10 clicks back off the maximum tightness works for most trailers. But factors like load weight, brake type, and components will impact the ideal adjustment.
Step-by-Step Adjustment Process
Here is the full process for adjusting your trailer brake shoes or pads:
- Jack up the trailer and secure it on jack stands.
- Remove the adjusting hole cover. On drum brakes it will be a round cover, for disc brakes remove the caliper.
- For drum brakes, insert a brake spoon, screwdriver, or specialized brake tool into the adjusting slot. Pry the starwheel up until the brake shoes push firmly against the drum.
- For disc brakes, tighten the adjustment hex screw until the pads squeeze the rotor.
- Back off the adjustment the specified amount – usually 2-10 clicks or half a turn. The exact amount will vary based on your trailer model.
- Check drum runout by spinning the tire and inspecting the fit.
- Replace the adjusting hole cover and lower the trailer.
- Torque the lug nuts to the specified setting.
Be sure to adjust each brake evenly so one side doesn’t carry more of the load. Uneven brakes can cause handling issues while towing.
Some newer trailers feature self-adjusting electric or surge brakes that automatically compensate for pad and shoe wear. For these models, no manual adjustment may be needed. Consult your owner’s manual or dealer – adjusting self-adjusting brakes improperly can actually cause damage.
Signs Your Brakes Need Adjustment
Watch for these clues that your trailer brakes need tightening or refreshing:
- The trailer surges or pushes the tow vehicle when stopping
- Braking feels uneven or pulls to one side
- You hear screeching, grinding or clicking sounds when braking
- The trailer is slow to respond when braking
- Excessive wheel lockup during hard braking
Any of these indicate worn pads or shoes, seized components, or loose brakes needing a tightening adjustment.
Uneven Adjustment Symptoms
If the brakes are adjusted unevenly side to side, you may experience:
- The trailer dogtracking or fish tailing while towing
- Premature tire wear
- Pulling to the left or right under braking
Adjust both sides equally to prevent these handling and tire issues.
Along with regularly adjusting your trailer brakes, be diligent about these maintenance practices:
- Inspect brake linings and drums every 6 months or 6,000 miles for wear.
- Lubricate brake components and check magnets on electric brakes.
- Check brake fluid level and flush lines every 1-2 years.
- Inspect brake wires and connections for corrosion.
- Check brake controller settings and power output.
Proper adjustment paired with diligent maintenance will keep your trailer braking safely for the long haul. Don’t let it drag on too long between adjustments!
Frequently Asked Questions
How often should I adjust trailer brakes?
In general, trailer brakes should be adjusted every 3,000 miles or 3 months. More frequent adjustments may be needed with heavy use or if you notice performance issues.
What tools do I need to adjust trailer brakes?
Basic drum brake adjustment requires a brake spoon, flathead screwdriver or specialized brake adjustment tool. Disc brakes use a hex wrench to tighten the caliper bolts. You’ll also need a torque wrench, jack, and jack stands.
How do I adjust electric trailer brakes?
Electric trailer brakes are adjusted the same way. Tighten the starwheel or caliper bolts to push the pads/shoes out against the drum/rotors, then back off to the sweet spot.
What happens if I adjust too tight?
Over-tightening the brakes can lead to overheating, rapid lining wear, and wheel lockup. If adjusted too loose the trailer will have delayed and inadequate braking.
How do I adjust hydraulic surge brakes?
Surge brake adjustment involves tightening or loosening the coupler nut to deliver the right pressure to the master cylinder and brake shoes when stopping.
Properly adjusting your trailer brakes takes some finesse and knowing what to feel for. But with the right incremental tightening and testing, you can dial in just the right brake performance for safe, smooth towing.