Trailering Guys

Answers To Your Boat Trailering Questions From The Experts

By Ted Sensenbrenner and Dustin Hoover

Outing Brake Fluid

Q: If I bleed my brake system on the trailer, does that remove all of the old brake fluid or will I still have some in the lines? Should I worry if there’s old brake fluid in there? Do you use brake bleeder kits?

Dustin:There comes a point during the bleeding process when you can almost push all the old fluid out. When we change a master cylinder, we push lots of fluid through the lines to clear out the old stuff. You need to open the lines and then push all the old stuff out by continuously adding new fluid. When everything coming out is clear, then you have done a good job and the system is filled with new brake fluid. As far as using brake bleeder kits, I find them to be time-consuming and difficult. I prefer having one person pumping the fluid in and another letting the fluid out. That works better than anything else.

Bolt Numbers

Q: My trailer's coupler seized up, requiring me to replace it. A friend that is well-versed in car trailers replaced it for me, but I have a concern that the installation is not correct for a boat trailer. The new coupler has three bolts (the old one had two), and the trailer has three holes; however, the coupler was installed using only the back two bolts on the coupler and the front two holes on the trailer, which does not look correct to me. Is there any advice you can give me?

Dustin: More bolts are always best. Make sure the bolts toward the front are single bolts in each hole rather than long bolts that span from one side through to the other side. Long bolts, when over-tightened, can pinch the front of the coupler, causing the coupler to bind. Jo responded: Dustin's answer was most helpful and directed me to know what to look for. All is great with the coupler and she tows like a champ! I'm glad I remembered you guys are there for me.

One or Two?

Q: I have a 20-foot center console on a single-axle trailer. Is this OK, or should a boat that size be on a dual-axle?

Ted: If the 20-foot boat doesn't weigh much, then it's fine. I like my 20-foot CC on a dual-axle trailer because it rides so nicely and doesn't stress the trailer. The general rule is, anything over 20 feet requires a tandem axle but a number of trailer manufacturers are basing the decision between single and tandem axle on the weight of the boat being carried.


Q: I have an older 1970s 23-foot Formula with a single sterndrive. Can you tell what size trailer I should be using? I do like the bunk style, but how much overhang should I have at stern?

Ted: The first thing you need to find out is how much the boat weighs, with everything onboard, including the weight of fuel and other supplies. Then you should visit a trailer dealer or their website to find a good match. Your tow vehicle must be able to accommodate the weight of the boat AND trailer. If you are close to your capacity, you might want to go for a single-axle trailer, which will weigh slightly less and have fewer components to maintain. You should have the bottom of the boat supported as much as possible. I wouldn't let more than two feet of hull overhang the end of the bunk.


Q: Could the color coding on my trailer connection to the truck be off if I connect green to green and yellow to yellow and so on, and continue to blow a fuse? What's my next step?

Dustin: Yes, it can absolutely be off. Brown is running lights, green is right turn, yellow is left turn, white is ground, and blue should be for a brake solenoid if you have disc brakes. Now, excuse the double negative, but this doesn't mean someone didn't change that. You need to trace the wires to see where each goes. As far as the fuse blowing out, that sounds like a short so you need to trace things out to see if something is pinched or rubbing. I speak from experience on this because it could be a million things. One other thing I do is check my truck with another trailer to see if the truck is OK. That way, you'll know if it's your truck or trailer causing the problem.

A Hull-Mark Moment

Q: I'm getting black marks on my hull from some of the trailer rollers. Does this mean they aren't turning and need lubrication, or does it mean it's time for new rollers because the surface is worn down?

Ted: When the boat is off the trailer, give each roller a spin by hand to see if anything is hanging up. I'm going to bet your rollers are aging and have seen too much sun. Try switching to the polyurethane rollers or thermo-plasticized rollers. They're stronger than black rubber and won't leave marks. They will also last longer and stand up better to the abuse. The other thing to consider is lubrication of the rollers or buying new components inside the rollers. Believe me, that does wonders to help them roll. If the components are rusted and dry, it's time to replace the bad parts.

Suspension Dilemma

Q: I'm going to buy a new trailer, and all the stuff I'm reading says torsion axles are the way to go instead of leaf springs. I trailer long distances and I'm not very handy at fixing things. Do you have suggestions as to what's going to work best for me?

Ted: Each setup has its advantages. A longer trailer hauling a heavier load tends to ride better with torsion axles and is a good choice provided the load is perfectly balanced, the tongue is level, and the tongue weight is within a safe range. If not, torsion axles can result in uneven tire wear. Leaf springs tend to have fewer uneven tire wear issues, but they also tend to have more parts like springs, shackles, and other connections that rust but are easy to inspect and fairly easy to replace. Torsion trailers have parts that will need to be replaced eventually, too, usually rubber bushings, which can be harder to replace. A final thought: Leaf-spring trailers tend to have a higher center of gravity, so if you have a tall boat, you might want to consider a trailer with torsion axles, which lowers the load's overall center of gravity. Also, a boat that is lower in the trailer means you don't have to drive as far down the ramp and can launch in shallower waters. Dustin and I vote for torsion axles because there are fewer moving parts that can rust or break.

Rotor Ruin?

Q: Is it true I shouldn't touch my brake rotors because the surface will be contaminated, or is this just a bunch of nonsense?

Dustin: You will not damage your rotors by touching them as long as your hands are not dirty with grease or oil. Too many people never even think about this. Rotors need to be clean to do their job. 

This article was published in Fall 2012 issue of Trailering Magazine.


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