Troubleshooting Brakes Locked Up on Surge Brake Coupler

Updated 09/26/2025 | Published 04/21/2025

Products Featured in This Question

Replacement Shock Absorber for Dexter Model 60 Brake Actuators

(117)

$68.94

Replacement Master Cylinder Assembly for Dexter Model 60 Brake Actuators - Disc

(79)

$137.01

Question:

I purchased a surge coupler from you about 2 years ago. Disc brakes While towing the trailer today, the brakes locked up driving forward to the point that I had to relieve pressure by opening the caliper zerks to get the wheels to turn. of course, now I do not have working trailer brakes. I do not have a visible shock absorber as identified as a potential problem in one of your parallel posts. Also, both wheel calipers froze up together so I don’t think it is a caliper problem. I’m thinking the master cylinder failed/frooze in a “braking” position. Prior to this the system was working great. What do you think??

asked by: Gene L

Expert Reply:

Hi Gene; I agree it is probably the master cylinder. I'm not 100% sure about the shock absorber since I don't see your order to know what actuator it actually is. However, I can't imagine you not seeing it is an issue if it worked for the last two years. If it is a Dexter Model 60 the correct master cylinder replacement is the # T4820000.

expert reply by: Robin H

Model 60 Master Cylinder
(click to enlarge)

Robin H.

9/26/2025

Hi Gene, did replacing the master cylinder solve the issue with your trailer brakes? I'm asking because your experience could help others facing similar brake problems.