Tech Articles

Emergency brake

On 1981 and later trucks, having the emergency brake seize up is a common problem in areas where corrosion is prevalent. This is especially true if the truck hasn't been used in a while. In fact, if you're going to park the truck for a while, leave the brake off!

The brake cable runs to the back wheels to a pair of sprung levers on the backing plates. The levers are attached with brackets called bellcranks, made of steel with an aluminum sleeve on the inside. It's the combination of metals that causes the problem: together, with a little water and salt, they form a cell, and thus corrosion. With a build up of corrosion, the lever can't move within the bellcrank, and the brake seizes.

The recommended (and free!) solution is to take the levers, springs and bellcranks apart (the latter unbolts, from the backing plate). Disassemble, and then pry the aluminum sleeve out of the bellcrank. Put it back together, perhaps with some plastic washers to take up some of the slack. There should now be enough free movement to avoid seizing.

I haven't actually gone through this. Instead I freed up my brakes with a mallet, big screwdriver for leverage, and lots of WD40. After an hour or two, things moved pretty smoothly again. Then I packed the whole thing with a lot of grease. I check them regularly, visually inspecting for full release.

If your parts, particularly the bellcranks, look bad, eaten away by rust, you're better off replacing them. Apparently the new bellcranks don't have the sleeve in them any more.