Does the manufacturer's operation/maintenance manual give this information?

Operation manual is revering to service book which I dont have.

Don't know about this particular kit, but on vehicle drum brakes with hydraulic (foot) and mechanical (hand) brake actuation, and no automatic adjustment - ensure both actuators are right back in the off position, temporarily disconnecting handbrake cable if necessary. Tighten the adjustment till the brake binds, then back off until it's just free.

If your brake is something like that the above might help.

Codey

AM77EF is double drum water fall design Mooring winch,the brake lining is fastened to the brake band with rivets that are countersunk.There is one brake actuator for each brake drum. About 8 spring loaded bolts are secured on top half cover of the brake drum.

OK, sounds like the brake band is on the outside of the drum, quite different from vehicle drum brakes. I'm not familiar with these things, and a web search didn't help. Is it manually actuated, or air applied, or spring applied with air to hold it off (fail-safe)? Can you see anything which you can adjust to bring the band closer to the drum? eg a nut on an actuator rod.

Codey

Normaly brake are engaged due to the powerful spring brake,released when air is applied via brake actauator to hold it off.On top cover of the drum there about 8 spring loaded bolts along the band which look like by unscrewing them may release bolt spring tension and bring the band closer to the drum.

That doesn't sound right. I'd have thought when the air is on the springs compress to a fixed point determined by a stop somewhere in the mechanism. When the air is released to apply the brake, the springs expand until the brake band meets the drum. But the springs will have limited travel available before they're stopped by something internal. If that happens before the brake band meets the drum the brake doesn't work. I think you need to adjust it with the air on until there is minimum clearance between the brake band and the drum (the drum only just turns). But just what you do depends on the details of how the brake is made. Any pictures or sketch available?

Codey

You are describing the manner in which a parking, or emergency brake works on an air brake truck. The regular service brake is air to apply, low tension spring to release.

Not in UK it isn't. The service brake is also air release, spring applied. Failsafe, if you lose air pressure, you can't move (though of course spring-applied parking brake would have the same effect). Earlier brakes were air applied, but above is an improvement for greater safety. I haven't been involved in it recently, but I doubt if they would have reverted to earliier type.

I'm pretty sure above is the case, but I wouldn't bet my life on it.

Codey

Thanks for the reply. Any one out there in Europe know how current air brakes are plumbed?

Bob

From a quick look on the web it seems I was mistaken, so apologies! The descriptions show spring applied just on the parking brake. I've read about the risks of using springs other than from non-original manufacturing, which were failing, but must have been for parking brake.

I'd have thought it simpler and cheaper to have spring-applied all round and no separate parking brake. Then only one actuator per wheel, and for parking just vent the air from the actuators, giving parking brake on all wheels. But no doubt "they" have thought of that and decided against .

I'll look a bit more, see if I can find anything else.

Codey

I'll look a bit more, see if I can find anything else.

While you are looking, see if you can find my marbles. I seem to have lost them.

You need a test weight with 100% of the hoist load spec to make these adjustments. With the load slung while traveling the load down brake should stop the load completely. The momentum of the load when stopped should not be able to force the drum to turn. Should stop it dead no drift to a stop at all. Once to that point the manufacture usually has some additional increase like 1/4 to 1/2 turn of the adjustment nut.

These are adjustment that i would send it out to be made. For one test weights are costly. The manufacture may have used the drifting back down of the load as indicator of over load and to get the load off of the hoist in a slow way. With gearing in a hoist it does not that much to stop some so it doesn't take much to over adjustment some.