Bearings and Brakes

Did you think bearings and brakes were related? It’s easy to agree they are in the same vicinity, but I think of one as going and the other as stopping. More than thirty years ago, when I hitchhiked from Chapel Hill, NC, to San Diego, CA, the Corvette I was riding in (maybe my tenth or eleventh ride of the trip?) suddenly had a rear wheel lock up and start skidding. A case of the bearing stopping the car, you see.

Wheel bearings, some say, can roll hundreds of thousands of miles without service if properly installed and kept clean. Remove the drum to inspect the electric brake parts and you have disturbed the clean environment of the bearings. It was the hard steel bearings and races separated from the dusty brake drums until a human opens the seal between the drum and the shaft.

Brakes can die from any number of causes, apparently, at any time. Springs can break, subsequently allowing the adjuster to fall into the drum and ruin linings and the drum surface. Wires (for electric brakes as on many travel trailers) wear and sever in two, rendering the brake for that wheel temporarily useless. Brake shoes may last 20,000 miles to 50,000 miles but if worn through the linings will ruin the drum surfaces, necessitating drum replacement.

Annual inspections of the electric brakes can allow easy detection of a number of faults or weaknesses. Skip the inspection and the owner is playing roulette with an expensive and, perhaps, unwieldy missile on the highways. We really do need to inspect our brakes annually. The wheel bearings will just have to accommodate this inconvenience. And we’ll do our very best to perform a technically sound job cleaning, repacking, and reinstalling the bearings.

It was with this sense of duty I began the chore of taking off our wheels and drums two days ago. Loosen the lug nuts while the tires are on the ground. Pull the front wheels onto blocks so the rear wheels are above the ground. Remove the rear wheels, then the drums. Clean the accessible old grease from the axle spindles and the drums and bearings.

Now I inspect the electric brakes wiring on the wheels. Look for continuity on the wires, and test the circuit to ensure the parts are all working. And guess what I found? Three wheels show damaged wiring, threatening proper operation now or in the near future. One wire was completely severed, one was nicked, and one was chafing. Locating and correcting these three problem areas makes the entire job worth the six hours I spent working on it. And this commits me to another careful inspection a year, at most, from now.

The most lengthy part of the job is removing all the old grease. Meticulously clean the bearings in solvent to remove all the grease, then blow them thoroughly with compressed air to drive out bits of grease, then clean in solvent again, and compressed air again, until no more grease comes out and the bearings are dry. Then the fun begins. Take a large walnut-sized ball of wheel bearing grease into my palm and press grease into the edge of the bearing until it squeezes out the other edge. Repeat all the way around the bearing until it is fully packed with grease and ready to remount on the axle spindle.

I remounted the hubs and adjusted the bearings for sufficient end play on the axle spindle. This allows the bearings to wiggle around just a little bit and not feel too tightly squeezed between the drum and the axle. I’m ready to reinstall the wheels, after rolling them down to the lower driveway where the air compressor is ready to check their air inflation pressures. Now a visitor drives up and asks if my father-in-law, John, is home? We talk a little while and I explain John is fishing at the NC coast with my brother-in-law and a few other men. The fellow says he’ll drop by Monday and talk to John then.

No sooner did I start mounting a wheel on the trailer than I realized I hadn’t checked the inflation on this tire and I didn’t install the hub cap in the wheel before remounting on the drum. I allowed myself to get distracted by the visitors and didn’t recenter myself before starting again. No big deal this time, but it may speak volumes for why some products are made better than others. Humans still make many things we buy and use. And we might sometimes forget just what we were doing. Then what happens? It could have had a bearing on our brakes this time. But I caught a lucky break.

Better lucky than good.

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One response to “Bearings and Brakes

  1. Brakes and tires … my nemesis. Yep, check ’em early and often. Good advice all around in this article!

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