How to Replace the Brakes on Husqvarna Chainsaws

The chain brake on a Husqvarna chainsaw is a crucial safety feature. You shouldn’t run the chainsaw if it is not working properly. The brake stops the chain instantly in a kickback situation, even if it’s running full throttle. A brake strap connects to the front hand guard and wraps around the clutch assembly. After much use the chain brake will need replacement as the clutch gradually wears it down until it’s too thin to stop the clutch.

Wrench

Screwdriver

Socket wrench

Piston stop tool

Clutch tool

All-purpose engine cleaner

Engine grease

Dismantle the chain cover by unscrewing both of the bar nuts with the wrench. Free the bar and chain from the clutch and remove them. Unscrew the chain guide plate to the right of the clutch with the screwdriver.

Pop off the circlip, the metal clip on top of the clutch, with the tip of screwdriver. Slide the washer, clutch drum, needle roller bearing and drive sprocket from the crankshaft stub; these parts are all interconnected and will pull off together. Below, you will see the clutch shoes and the clutch spring.

Unhook the spark plug cable's black rubber boot from the end of the spark plug. Fit the socket wrench and remove the spark plug. Insert the rubber piston stop tool into the spark plug’s vacant hole. Turn the clutch assembly by hand until it stops spinning.

Attach the clutch tool around the clutch hub, and loosen the clutch hub by turning the tool clockwise. Free the clutch assembly, which includes the springs and shoes, from the crankshaft. They will pull off together. Push the front hand guard, on top of the engine, forward to activate the chain brake. Unscrew both hand guard bolts, one on each side of the engine, which hold the hand guard in place.

Loosen and remove the four bolts holding the chain brake cover over the brake system. Pry out the cover, using the end of the screwdriver. Locate the lever arm and retaining bush on the top of the brake, just before the top of the engine; they will look like a small arm and pivoting joint, and will have a spring connected to them.

Push the retaining bush down while pulling the lever arm out. Slip the tip of the screwdriver underneath the rear end of the pressure spring. Release the rear end from the hook. Disconnect the brake strap from its hook on the toggle joint just beside the retaining bush, and pull them out. Pry the spring and retaining bush out slowly, while keeping your hand over the spring to prevent it from snapping out.

Clean all of the parts with an all-purpose engine cleaner. Inspect them for signs of damage. Replace the necessary brake parts, the toggle joint and brake strap to the clutch. Seat the strap into the engine. Grease the toggle joint’s moving parts.

Grease and install the lever arm. Grease the retaining bush, and push it down with the spring connected to it. Hook the rear end of the spring onto its seat. Connect the retaining bush to the lever arm. Set the brake cover in place, and tighten all four of its bolts.

Reattach the front hand guard, and tighten both of its bolts. Set the chain guide plate in place, and tighten its screw. Pull back on the front hand guard to disengage the chain brake. Make sure the brake strap is recessed into its slot behind the clutch assembly area. Reassemble the clutch parts in reverse order from the way you disassembled them. Reinstall the cover, bar and chain. Remove the piston stop tool, and reconnect the spark plug wire.