The Farmall letter series tractors are very popular with antique tractor collectors, and they still used by farmers in 2011. The Farmall M began production in 1939 and ran though 1952. The M was offered with a gas and a diesel engine. All the letter series tractors use the same brake system, which consists of a brake drum connected to each wheel with a brake band around them. The brake pedals can be applied individually to help turn the tractor or to stop one wheel from spinning. Lock the pedals together to use as one.
Clean the threaded clevis adjusters or the threaded brake adjuster bolt with a wire brush. The brake adjusters are located at the brake housing on each side, with a separate pedal adjusting rod at the pedals.
Spray penetrating oil on all the adjusting threads and mechanism.
Loosen the lock nut on the brake adjusting clevis or threaded rod protruding out of the brake housing. Thread the brake adjuster so it pulls the brake band tighter. Allow about one inch of free play in the pedals. Adjust the brakes individually using the left and right side adjusters.
Adjust the pedal rods to align the pedals after adjusting the brakes. The brake pedals must remain even so the brake pedal combination lever can join the individual pedals to act as one.
Retighten the brake adjuster lock nut to lock the adjustment. Retighten the pedal position lock nut to lock the pedal position in place.
The Farmall M was produced for over 20 years, and some of the newer M models used a brake disc with a mechanical disc expander. The adjustment is still made at the brake pedal and the adjustment from the brake housing. Be sure the seals on the brake drum or disc are not leaking. If the seal is leaking, adjustment will not help. Apply heat to the adjustment bolt as needed to break it loose.
Always wear safety glasses when working in or around motorized equipment. Be careful when applying heat to loosen adjustment nuts.