Breathe New Life into Aged Brakes
Brakes can be a hit-and-miss proposition on many tractors. The concern here always is safety. A good set of brakes is crucial when loading and unloading a tractor. They are essential when parading through streets lined with folks.
So always make it a point to examine brakes and adjust and repair whenever necessary.
Three Brake Types
Basically, a brake system on an older tractor is one of three types:
• Externally contracting band brakes
• Internally expanding Bendix drum brakes
• Disc brakes
Late-model tractors may have hydraulic brake systems. Leave those to the professionals!
Before working on brakes, be sure to refer to your tractor’s service manual or an I&T Shop Service Manual (913/341-1300).
The first step to boost stopping power is to expose the mechanism by removing all coverings and cowlings. Once in, test all working parts to make sure they’re moving freely – but not too freely. Don’t forget to examine the condition of the brake’s linings or pads.
While you’re at it, give the brakes a thorough cleaning. Clear away any debris that might be clogging up working mechanisms. Then remove any surface rust with sandpaper or emery cloth.
If everything is in working order, then it’s possible you’ll only have to make adjustments. This may require raising the rear wheel of the tractor off the floor. Tighten the brakes until you can’t physically move the rear wheel when you rotate the brake. Next, back that adjustment off a bit until the brakes rotate with a slight drag.
Another procedure calls for depressing the brake pedal 2 inches or engaging the lever (again, this depends on brake type and tractor make). Next, adjust the brake until the lining makes contact. As a rule, a brake’s lining or bands should contact the drum when you depress the pedal just ¾ to 1 inch.
While operating the pedals or lever, make sure they move smoothly and in a straight line. If not, you may have to renovate pivot points with bushings or replace a worn casting.
Also examine springs to see if they are stretched out and replace them if necessary. Look at the adjusting clevis or stops. If during your examination you find that repairs are in order, start with the brake lining or pads. If linings aren’t oil-soaked, they can often be renovated just by scuffing up their contact surface with sandpaper.
A warning: Most brake lining material contains asbestos. Because of that, be sure to wear a mask when sanding or removing brakes.
It is possible to dry out oil-soaked pads by lightly heating them with a torch. Before resorting to this, make sure that lining replacements are available and not too costly. It is always better to replace old linings, if possible. Otherwise, try the torch method and see if it works.
Renovating band brakes can be a simple job. Often, replacing the bands and making some adjustments are all that’s required.
Automotive-type drum brakes may need professional help. Long wear and particularly the creation of excessive heat during use can distort a drum’s surface (referred to as coning or bell mouthing). Uneven wear on the lining is a good indicator of this.
Truing up a drum requires a metal lathe and, thus, is best handled by a mechanic or machining shop.