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Parts Needed To Replace Hydraulic Braking System On Boat Trailer


Im looking to replace/upgrade the brakes on my boat trailer. Boat weighs about 6k lbs. tandem axel. currently brake system is shot. do you offer a marine grade or water friendly drum brake? seems more boat trailers are going electric. thx


Expert Reply:

Hydraulic systems are preferred on boat trailers because water and electricity do not mix well. The hydraulic surge brake system is self contained on the trailer and the only connection to the vehicle is the reverse lockout switch that is powered through the trailer connector. This switch keeps the surge coupler from locking the brakes on the trailer when you are backing up.

I know that you told me that your boat weighs 6k, however I need your help to identify the axle so we can select the correct brake assembly. Depending on how the trailer was made there will be a few spots you can check to identify the axle. First, if the trailer was pre-made by a specific company you may be able to find this information in either the paperwork or on a placard somewhere on the frame.

Another way to find what drum brakes fit is to measure the diameter and width of the hubs (see picture). Ideally you would be able to get the measurement of your hub by using a precision instrument like a tape measure or ruler.

Sometimes, the axle identity is stamped into the axle itself or into the hub if it was purchased as a complete assembly.

The bearings, races, and seals should have an industry standard number on the back edge which can be used to match replacements.

If you cannot find any markings or notation for the axle, you will need to look for replacement parts based on the capacity and dimensions of your existing parts.

For example, if your boat trailer has a two 6000lb axles, then the Hydraulic Brake Kit you will need is # T4489600-500. These brakes have galphorite plating that delivers superior corrosion protection. The backing plate and shoe levers are sealed with permanently bonded electrocoat primer. The second coat of rugged acrylic is applied to backing plate which is nearly rustproof.
The wheel cylinders are treated with hot black oxide and the internal components are olive drab and zinc plated.

Since the brake system on your trailer is shot I can definitely get you started with replacement parts you will need.

If you need an actuator and your trailer will not exceed 12,500 lbs and, I recommend looking at a coupler like the Titan Zinc-Plated Brake Actuator for Drum Brakes # T2477600 . Using a coupler with a significantly higher weight capacity could result in poor braking. This coupler can be bolted onto a 3 inch wide channel tongue and also comes with a protective shield in case you add an electric lockout solenoid valve, # T4748800. The solenoid valve will allow you to back up your trailer without actuating the brakes.

You will also need brake lines. For this, you can use the Tandem Axle Hydraulic Brake Line Kit, # 9579-2. Lastly you will need the brakes and you will be set to go.

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