Highway 1 and brake chatter

[bevman]

On my recent trip from Ferndale over to Fort Bragg (CA) on Hwy 1, it was about an hour of hairpin turns, something that I've never done. About half way, and at speeds under 20 mph, the brakes would grab and chatter. Is this a heat issue, or something that needs repair attention?

[overlander63]

I think you should take a look at them. It could be something as innocuous as brake dust, or as serious as a brake lining worn off.
My gut feeling is the drums may need machining. The part that may need machining is the flat part the magnets ride on. You do still have electric drum brakes? Discs would be another matter.

[Excella CM]

Did the problem go away when the brakes cooled down?

[bevman]

Yep, they are electric drums, and OLD... got the round magnets. I took off the drums not too long ago to check bearings and brake lining. Linings are more than half thick, so that's good. The magnets have a few more trips still on them. I adjusted the star wheels at that time.

As to the cool-down... I spent the night in Mendocino, and at the front end of the way home the problem reoccurred at slow speeds (cool brakes) but, since the road wasn't nearly as serpentine, it wasn't a problem.

[uwe]

Originally Posted by bevman

Yep, they are electric drums, and OLD... got the round magnets. I took off the drums not too long ago to check bearings and brake lining. Linings are more than half thick, so that's good. The magnets have a few more trips still on them. I adjusted the star wheels at that time.

As to the cool-down... I spent the night in Mendocino, and at the front end of the way home the problem reoccurred at slow speeds (cool brakes) but, since the road wasn't nearly as serpentine, it wasn't a problem.

I would take another look at the brakes. Inspect every aspect, and replace the backing plates as a unit if you find worn components. I would also have the drums machined, or get new ones. My 58 flying CLoud has original brakes - they don't work so well either...My plan is to upgrade to discs once the trailer gets more attention. I run discs on my 1963 Overlander. That is one of the best upgrades I have ever done.

[Excella CM]

You may have a faulty circuit. Check the wiring for lose or shorted wires at the plugs and in the umbilical. You may be getting uncommanded brake application due to crossed wires.