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Old June 24th 17, 08:03 AM posted to rec.aviation.soaring
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Default 1987 Cobra Trailer Brake drum removal

Based on my older Komet and 1992 Cobra (they both use ALKO axles): remove the grease cap, then remove the cotter pin and large spindle nut. The outer wheel bearing should easily pop out in your hand and the brake drum should be removable with just a little tug.

In the real world, the spindle nut comes off easily but everything else is stuck together, which is probably where you are now. Make sure the brakes are off. Back off the manual adjuster by using a screwdriver to click the teeth of the toothed "star wheel", accessible from the inner side of the backing plate (crawl under the trailer and you'll see a slot in the back of the steel plate the the brake drum almost touches, possibly with a rubber plug.. The direction is marked by an arrow, which I think tightens it. To loosen it, use a second, smaller screwdriver to hold the pawl away from the starwheel and turn it.

If that doesn't help, with cars and vans, one technique is to rap the face of the drum sharply with a big hammer a few times to knock it loose. But you could crack the drum so for my trailers, I've used a 2- or 3-jaw puller, possibly with (IIRC) short lengths of chain or longer bolts or other jury-rigged device to pull the drum off. It only takes slight movement to break it free, then it should slide off. Older AL-KO axles don't, I believe, have a retainer screw that most be removed; the drum is held on by the wheel and lug nuts. They also don't have threaded holes into which you can insert bolts and tighten them up, forcing the drum away from the hub.

If the bearings are damaged, removing the inner race of the inner bearing may be difficult, requiring judicious application of heat (torch) and large Vice Grips. The parts--bearings and grease seal--are available here in the U.S. but you may have to order them so don't start this repair on Saturday morning expecting to have the trailer driveable the same day...or even week..

Google how to clean and pack the existing bearings or packing new bearings, and how to remove the grease seal (probably bending it in the process) and replacing it with a new grease seal, and then reassembling it and retightening the spindle nut correctly.

If the brakes got the whole hub assembly pretty hot, you might want to replace the springs inside the mechanical drum brake itself when you replace the brake shoes. The springs pull the brake shoes away from the inside of the drum when the brakes are released so if those springs are not strong enough, the shoes could hang up causing even more overheating.

Take photos of everything you disassemble to make reassembly easier. The AL-KO mechanical actuators are very similar to conventional hydraulic drum brakes but different enough that it can be difficult to reassemble a brake if you don't know where all the parts go.

Chip Bearden
"JB"