Drum Brake System: Service and Repair

DISASSEMBLY





1. After removing the wheel, remove the brake drum.
2. Remove the shoe hold down spring, the automatic adjuster spring and adjuster lever.





3. Spread the shoes and remove the shoe adjuster.
4. Remove the shoe to shoe spring and shoe hold down spring.

INSPECTION





1. Measure the brake drum inside diameter. Check the runout of brake drum using a dial indicator.

Standard value:
Inside diameter 180 mm, 7.10 inch
Limit:
Inside diameter 182 mm, 7.165 inch
Limit:
Out-of-round (brake drum) 0.015 mm. 0.00006 inch





2. Measure the brake shoe lining thickness.

Standard value:
Lining thickness (leading) 4.5 mm, 0.177 inch
limit:
Lining thickness 1.0 mm, 0.039 inch
Standard value:
Lining thickness (trailing) 4.6 mm, 0.181 inch





3. Inspect the brake lining and drum for proper contact.
4. Inspect the wheel cylinder outside for excessive corrosion and damage.
5. Inspect the backing plate for wear or wear or damage.

REASSEMBLY





1. Apply the specified grease to the locations indicated in the illustration and to each component.
- Shoe and backing plate contact surfaces
- Shoe and anchor plate contact surfaces

Recommended grease: Multipurpose grease SAE J310, NLGI No. 2





2. Install the shoe hold down pin.





3. Assemble the return spring with the push rod shorted.
4. After assembling the drum components, pull the parking brake lever all the way up several times.