Weak Brakes on One Axle of Tandem Axle Trailer

Updated 07/22/2022 | Published 07/21/2022

Products Featured in This Question

Brake Adjustment Spoon for Drum Brakes

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$8.08

Digital Multimeter with 42" Long Test Leads - XL LCD Display

(5)

$40.24

Question:

Weak brakes on rear tandem axle on kaufman 3 car wedge 50ft trailer. I recently had the trailer rewired using 10 gauge wire for the brakes from the connector to the rear axles. Checked all the connections and cleaned all the grounds. Replace both magnets on the rear axle and adjusted the brakes. Pulled for a hour and half to let the new magnets seat. I turned the brake controller to 10 max for 2015 f350 factory controller and the forward tandem axle brakes lock up but as I slightly pull the trailer I can see the rear axle wheels start moving while the forward axle tires are locked and sliding. Re adjusted the rear axle and repeat the process but same results. I had someone hold the manual lever on the controller and I can hear all the magnets humming. Could really use your expertise on this problem, thanks.

asked by: Jameel M

Expert Reply:

So the first thing you'll want to do is just check the brake magnets to see if there is proper power getting to them, which you will need to do with a multimeter like the Digital Multimeter # PT29ZR. I've added a link below to a help article which explains how to do this, but you'll want 3.2-4.0 Max amps at 12-13 volts.

If that's fine, it is possibly the ground being weak at the rear axle. I'm not sure where your ground is, but you can try and relocate the ground wires from the magnets to the frame near the brakes as opposed to running them to the junction box, which can help minimize power loss.

Your brakes may also need to be re-adjusted with brake spoon # W80630 if they are manual adjust brakes as this can also be an issue with weak brakes. Finally, check the actual wires since you mentioned you had it re-wired to make sure the wires are not somehow pinched, punctured, or otherwise damaged.

expert reply by: Kyle S