Trailering Guys

By Ted Sensenbrenner and Dustin Hoover

Please, Let's Not Float Our Trailers

Q I have a trailer with 12-inch wheels. If I install 15-inch wheels, do you think the trailer will float?

Ted: This might seem like a silly question to some, but I've seen it happen. I once delivered a boat on an aluminum trailer with aluminum wheels and it floated once the boat was off-loaded. The real trick was getting the boat back on the trailer when trying to retrieve it. At issue is this: will larger tires with a higher PSI, make the entire trailer float? Dustin and I agree that you're probably not going to have any trouble with a too-buoyant trailer so long as it's made of galvanized steel. If your trailer is aluminum, the situation changes because aluminum is so much lighter and that's when you might be facing a floating trailer. One more thing that is going to help if the trailer is bunk: Use cypress wood because it's denser which means it's heavier than the usual pine used to build bunks. If you have a roller trailer, this is a good time to make sure you have galvanized brackets. But you've got one more concern, and this is important: Will the larger tires hit the fenders? If so, then that's a bigger problem because the trailer isn't going to be able to move. Let us know how this goes.

What's The Hang-Up Here?

Q I have a dual-axle trailer with surge drum brakes on the front axle only. The left brake locks up regularly either after having the trailer parked for a while (backed uphill) or when applying the brakes going down the road. It doesn't happen on the right side. I've removed the drum to verify proper lubrication; I've adjusted the brake shoes both looser and tighter; I've bled the brake lines and had a shop bleed the brake lines. The trailer is essentially new, 2010, and typically only driven a few miles to the water, although I've taken it to Maryland and back to Vermont twice. Any ideas?

Dustin: The brake wheel cylinder could be hanging up, causing the wheel to lock. This happens a lot with drum brakes and it's not always obvious why they do it. We've had to take many, many brakes off trailers and replace them and the drum because we just couldn't find a distinct problem. Proper lubrication is a good first step. While you're in there, carefully inspect the return springs and where the shoe and backing meet, and ensure it's properly lubed and free of corrosion. If that doesn't change anything, it's easiest to replace the cylinder instead of wasting time trying to find the missing link, or should I say "kink."


Q My brake line has a 3,000-psi pressure rating. I noticed there are brake lines that use only 1,200 psi. Is this because of the difference between drum and disc brakes?

Photo of a boat trailer brake line

Ted: Most brake lines will handle the psi load of both drum or disc brakes. Disc brakes do have a higher psi because they activate stronger and harder. It never hurts to go heavy on an item such as a brake line. Generally speaking, lighter trailers tend to use drum brakes and use lighter brake lines. The physics of drum brakes is such that there's a levered force at work, which delivers better braking torque at a lower hydraulic pressure. Disc brakes require higher static-line pressure for effective braking. You often see trailers lighter than 3,000 pounds GVW (gross vehicle weight) with drum brakes, which are cheaper and more effective. For trailers over 3,000 pounds, braking performance is comparable with both drum and disc brakes. I prefer disc brakes as they tend to have better performance when driving in the rain because the water is flung from the braking surface, whereas water can pool slightly in the drums on drum brakes.

Weight Or Wait

Q I'm pulling 3,500 pounds with a 2-inch hitch ball. I've seen other 2-inch hitch balls that can carry 5,000 pounds. Do I gain anything by getting a heavier one even if my boat and trailer weigh 3,500 pounds fully loaded?

Dustin: You're not going to gain much by going to a larger-rated ball other than peace of mind. The larger rating is probably because the ball has a larger shank with which to bolt it on.

Ted: A 2-inch hitch ball is usually affixed to a Class III or Class IV hitch and has a 1-inch shank diameter. If your 2-inch ball is affixed to your bumper, it makes no sense to increase the hitch-ball capacity because your bumper can't handle a capacity of 5,000 pounds. If you're using a standard Class III or Class IV hitch, the beefier the better. A 2-inch ball can go up to 8,000-pounds capacity and even greater. But over 8,000 pounds, I'd consider using a 2 5/16-inch hitch ball. Trailer hitch balls are sold in various shank lengths and diameters, ball diameters, and weight capacities to meet your towing needs. It sounds like what you have now fits the bill, so I wouldn't change anything.

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