Troubleshooting a Dico Surge Brake Coupler on Boat Trailer with Disc Brakes  

Im inquiring about my boat trailer surge coupler. The trailer make is Trail Rite and as best I can tell, its using a Dico 12,500 coupler with possible a Dico model 60, maybe? master cylinder. The boat and trailer combo probably weighs no more than 6000lbs fully loaded and both axles have disks. My question is this: I realize that youre supposed to get a clunk when you pull away from a stop as the master cylinder extends but what Im experiencing is ridiculous. Ive gone so far as installing two shock absorbers in the coupler but it makes no difference. Im beginning to wonder if the master cylinder is bad and compressing too much. Can you confirm the ID of this coupler and maybe give me some insight as to what I could do to stop the excessive clunking? It almost seems like this coupler is overkill for this application. Would a smaller coupler do as good of a job but more smoothly? Here are a few pics- Thanks!

asked by: Paul H