Replacement Disc Brakes and Actuator for Magnum Boat Trailer

Updated 12/08/2025 | Published 11/27/2025

Products Featured in This Question

Dexter Surge Brake Actuator - Disc - Elec Lockout - 2" Ball - Zinc - 7.5K - 3" x 5"

(266)

$347.58

Kodiak Hydraulic Brake Line Kit - Single Axle - 18'

(164)

$164.44

DeeMaxx Disc Brake Kit - 10" Rotor - 5 on 4-1/2 - Maxx Coating - 3,500 lbs

(64)

$420.68

Demco Hydraulic Brake Actuator w/ Electric Lockout - Disc - Zinc - 2" Ball - 7,000 lbs

(134)

$213.36

Kodiak Disc Brakes - 8" Hub/Rotor - 5 on 4-1/2 - Dacromet - 3,500 lbs - E-Z Lube

(73)

$505.36

Question:

Good afternoon, I have a Magnum boat trailer that I would like to replace the current disc brakes with something newer. One side appears to have a broken pad seat, but even if I found that part, Im not sure of the overall condition of the calipers due to the previous over by passing the surge actuator and the actuator no having any fluid in it. All of that brings me to my question. What would a budget friendly recommendation to upgrade the current brakes? The part number on the front follower hubs is H-1377, which I believe is a 3500 lbs. hub. Also, I know I will need to replace the actuator. With that said, do you have a recommendation for the actuator? I have not taken it off yet to see what other numbers on stamped or on a tag, but there is a tag with the number 19383 stamped on the underside of the actuator. Please let me know if you need additional information. Thanks, Michael

asked by: Michael S

Expert Reply:

Hey Michael! It sounds like that is a UFP H-1377 which would be a 3,500 lb hub using the standard bearing combination. I'm guessing you have slip on rotors based on that information. If you want to use the existing hubs the DeeMaxx Disc Brake Kit # DE42FR is the best option. If you want to go ahead and replace everything I recommend the Kodiak Disc Brakes # KOD87FR which cost a little bit more. Disc brakes are always on the higher end, these are the most budget friendly available.

I don't have any information on an actuator with that number but if you're using a 2" ball and have a 3" wide trailer tongue I recommend the Demco Hydraulic Brake Actuator # DM62VR. This has an electric lockout and can handle up to 7,000 lbs which is enough for most trailers. It also has the Demco eZ-Latch which makes hooking up a lot easier.

Since it sounds like everything is pretty worn I also recommend inspecting the brake lines. It wouldn't hurt to replace them with # 18SI-BLKIT while you're at it.

What kind of boat do you have?

expert reply by: Robin H

Demco Hydraulic Brake Actuator
(click to enlarge)

Michael S.

11/30/2025

Good morning Robert, Thank you for getting back to me. I have a 2000 Stratros 20SS Extreme bass boat. I believe the hubs and rotors currently on the trailer are all one piece; at least that is what I remember when I changed the seals and bearings when I bought the boat a year and a half ago. With that said, I'll go with the Kodiak Disc Brakes (#KOD87FR). That will let me replace everything, even if the hubs and rotors are two-piece, so that I can have everything new. Yes, sir, I have a 2-inch ball. However, the current actuator appears to be welded to the tongue. The measurements of where the actuator slides into are 3.5 inches wide, 17.5 inches long, and just over 4 inches tall. The center of the reservoir cap is 9.5 inches. I tried to upload or paste pictures into this reply, but I couldn't figure out how. Nonetheless, it appears that the actuator and housing I currently have on my trailer are Dexter DS7.5L A-60L. Again, I can't find a number other than the number on the tag mentioned above. However, on top of the housing, UFP is stamped into it with a max trailer GVRW of 6,000 lbs. If I have Dexter DS7.5 L A-60L, would the replacement for the inside components be DX99FR? Thank you for recommending the brake line kit. I inspected them while replacing the bearings and seals. While they looked okay, they appear to be the original lines. Even if they are okay, how long will they last after several years? I would rather replace them while I'm doing all this work than have to go back a month or two later. Thanks, Michael

Robin H.

12/2/2025

@MichaelS good idea, I would go ahead and completely replace them with the # KOD87FR as well. Pictures were never going to work here since they can't be added in the comments. If it looks like the Dexter DX7.5L A-60 it probably is, and that inner member # DX99FR would slide right in the old housing. However, you can save some money grabbing the whole thing # DX63FR so I would do that. You can pull the inner member out and you will have a spare housing if you need it for some reason. Hard to say on the brake lines, so many possible variables. Depends on the material and how everything was cared for, how it was stored, where you're located (somewhere like Florida is especially rough on trailers), etc. If they're rubber I would go ahead and do it. The # 18SI-BLKIT is for a single axle and if you you have tandem you can use # 18TA-BLKIT.

Michael S.

12/7/2025

@RobinH, Luckily, I am not on the coast, but the age of the trailer and the overall condition of the brakes led me to believe the lines are the original. I agree with you, replacing the lines would be the best course of action. My luck, they will fail the minute pressure is applied. One more question, where can I find the mechanical lockout tab pictured in DX79FR? I looked through etrailer's website, but I couldn't find it. I move my boat around my garage and shop using a trailer dolly, and need the tab to lock out the brakes when doing so. The previous owner slid a bolt head into the slot and used electrical tape to hold it in place. Thanks, Michael