View Full Version : Hot Hubs

06-06-2008, 12:03 PM
Upon returning from lake (15 miles) I noticed both hubs were hot. My attention was drawn to the hubs when my hand was near the fender. It felt unusually warm. I felt the hub. It was hot enough that you wouldn't want to hold onto it for more than a few seconds. Also noticed the grease, in liquid form, was running out the small hole in the bearing buddy. Checked the other hub. Same deal.

Now at the end of the season last year I serviced the hubs. I cleaned the bearings, replaced the grease seals, and repacked. Start of the season I pumped in some grease (red tacky expensive stuff). Each day I pull the boat I check the hubs to see if more grease is required. Never noticed a problem before.

I plan to pull the hubs apart to inspect, clean, and repack. Any idea what kind of problem I should be looking for?

06-06-2008, 12:17 PM
If I was going to pull my hubs apart.... after they were extremely hot... I would replace the bearings, races and seals. I'd hate to lose a wheel on the freeway. Bearings, races and seals aren't very hard to replace by yourself and not too expensive. Pays to be safe! Rick

06-06-2008, 12:21 PM
Roger. Thanks.

06-06-2008, 12:24 PM
I dropped bearings and tore my hub up a couple weeks back - service the bearings today!! - it gets expensive to machine out a spindle and replace bearings, hub, etc.

06-06-2008, 12:26 PM
And to think that I almost didn't read this thread because I thought it was about Hot Tubs.

06-06-2008, 12:47 PM
And to think that I almost didn't read this thread because I thought it was about Hot Tubs.

Same here!!!

06-06-2008, 01:31 PM
My right hub still gets a bit warm even after replacing seals and repacking. I think that I have a brake that is dragging.

06-09-2008, 06:31 AM
Brakes are the problem. When I removed the brake drum thick black mud mixed with small rocks surrounded severely rusted brake components. Our lake has a gravel (and mud) launch ramp that we built ourselves.

Replaced the bearings, sleeves, and grease seals. Removed, cleaned, rust treated, and painted the brake components. When I reinstalled them I used a liberal coating of anti-sieze lubricant. Really need to replace all of the brake components in the near future.

Still found that it was dragging the brakes. Traced it to the tongue where the surge brake portion of the trailer is supposed to move back and forth to activate the brakes. Sprayed some WD-40 (saturated actually) into the area to free it up.
Not sure if corrosion is the problem. May be that the tongue rides about 1-1/2" too low with my drop hitch.

Anybody have any ideas what to do about dragging brakes?

Vern Swieringa
06-09-2008, 06:45 AM
I would check the brakes. I had to replace all the calipers on my '03 tandem axel trailer within two years.

06-09-2008, 09:08 PM
I just did the entire brake system on my '98 single-axle Mastercraft trailer. What do you want to know?

I'll tell you a few things I learned:
1. New brake shoes ($80) aren't significantly cheaper than two entirely new backing plates ($120), and the new backing plates come with new shoes, springs, hold downs, and slave cylinder.
2. A new UFP actuator is about $200.
3. Once you've replaced those two, a complete change-out of the steel brake line tubing is like a walk in the park.

So, for about $400, you can have a brand-new brake system, and you won't have to try to diagnose individual issues.

BTW, if you have a similar trailer, I have a couple of sets of 12x2 shoes that I can let you have cheap...

From your description, the problem may be a rusted master cylinder or brake line - the surge from applying the brakes on the truck may be enough to pressurize the brakes, but there may be no way to unpressurize them. Drive the trailer normally, stop, and jack up one wheel. It should turn freely - if it doesn't, try opening the bleed valve on the slave cylinder, and see if the wheel will turn freely afterwards. If so, it could be either the main brake line or the MC itself.


06-09-2008, 09:29 PM
A frozen piston in the caliper will lead to dragging brakes .... I suggest you push the piston with a caliper tool or C-clamp ..... see if they move back a bit under pressure ...

you should also verify that the spring on the actuator/master cylinder is really pushing back on the release of the brakes (as the tow vehicle pulls the trailer) .... so I usually jack a wheel (leaving the tire on for safety) and push the actuator while someone spins the wheel and then check the brake release as I release the actuator .... test all your wheels and you will quickly know if it is brake related heat. If the wheels release then we may be back to the hub.

Keep us posted.

06-09-2008, 09:31 PM
I would also add that the 2 guide pins for the actuator should have a decent marine grease and not just WD40......... make sure the actuator has full travel without binding and restores to a fully extended position easily. .... sorry for 2 posts.

06-10-2008, 10:21 AM
How are the brakes measured? Is it the inside diameter of the drum? I am considering replacing both backing plates (complete).

06-10-2008, 10:53 AM
I had the same problem with my last trailer. It turned out to be a vapour lock in the surge brake, sticking them on.

The first thing I'd check is brakes. pull the wheel and have a look (once I had a piece of the brake mechanism fall off - made a heckuva mess), make sure it's clean and working. The put the wheel back on and make sure it spins freely. Might as well have a look at the bearings while the wheel is off.

After the issues I've had I tend to check the hub for heat whenever I stop.