Parts Reminder List
BASIC SERVICE- New or rebuilt shoes/linings
- Emery cloth or light grade sandpaper
- High temperature silicone lubricant
- New/fresh brake fluid
IF REQUIRED BY INSPECTION
- Hardware and spring kit
- New drums
- New wheel cylinders
IF WHEEL CYLINDERS ARE TO BE OVERHAULED
- Wheel-cylinder overhaul kits (2)
- Brake assembly lube (optional)
OPTIONAL BUT HIGHLY RECOMMENDED
- Aerosol brake cleaner
Shoes/Linings
- Compare new and old shoes/linings. They should match exactly in shape and lining width. Check that the spring connection holes in the brake shoe support web are in the same places.
NOTE: Due to the Self-Energizing design of drum brakes, the leading (forward) shoe is smaller in size than the trailing shoe. Incorrect installation (reversing) of the shoes will result in excessive brake grab or lockup.
- New shoes may occasionally require some pre-assembly. Spring and emergency brake pivot points may need to be transferred from the old shoes to the new shoes.
Emery Cloth or Light Sand Paper
- During installation the friction surface of the new shoes/linings may become contaminated with grease or dirt. This contamination should be quickly removed by very lightly sanding (by hand) the affected area. Any lining which requires more than very light sanding to remove the contamination should be discarded.
NOTE: Oil or grease contamination of the linings will cause brake grab or brake lockup.
High Temperature Grease
- High temperature grease is required to lubricate the contact points between the shoes/linings and the backing-plate. Internal drum temperatures can rapidly increase to greater than 300 ° F during normal braking. Normal wheel bearing or lithium based grease will rapidly melt and contaminate the brake linings and drum.
Brake Fluid
- Proper bleeding and flushing of the brake system will require a minimum of 16 oz of brake fluid.
- Never mix DOT 3 or 4 (light amber in color) with DOT 5 (purple in color). There have been reports of damage to brake system seals when DOT 3/4 and DOT 5 fluids are mixed.
- Always store brake fluid in a sealed container. When left open brake fluid will absorb moisture from the air. This reduces the boiling point of the brake fluid and could lead to a soft pedal or brake system failure during prolonged or emergency braking.
- Never add automatic transmission fluid, engine oil, or power steering fluid to the master-cylinder. Petroleum based fluids will cause the rubber seals and gaskets in the brake system to swell and leak.
Hardware and Spring Kit
- Replacement springs are normally color coded. Prior to installation match the color, size and shape of the new springs with the old springs
- Mounting and adjusting hardware may be specific to the left or right side drum. When removing the shoes/linings it is highly recommended to complete one side (remove and install) prior to begining the next side.
Drums
- Closely compare the old drum with the new drum. The diameters and widths should match exactly.
- New drums are often covered with an oily film or protective coating to prevent oxidation or rusting during shipping. This coating should be completely removed prior to installation. Soap and water or generic solvents are often the most effective in removing this substance. After removing the coating the drum should be rinsed thoroughly with brake cleaner to remove any remaining residues.
New Wheel-Cylinders
- If the wheel cylinders are to be replaced it is very important to verify that the new wheel cylinders are the same diameter as the old ones. One type or style of wheel-cylinder will often be available in several different diameters.
The wheel-cylinder diameter is directly proportional to the pressure developed. Wheel cylinder diameters are closely matched with the:
- Master Cylinder
- Proportioning valve
- Brake shoe surface area
- Vehicle weight
Incorrect mixing of wheel-cylinder diameter will result in:
- Very sensitive brakes, prone to grab and lockup (diameters too big).
- Steering Pull (different diameters side-to-side).
- Reduced braking performance or nose diving upon braking (diameters too small).
Wheel-Cylinder Overhaul Kit
- Overhaul kits will generally come with several different sizes of cups and dust seals.
- The sizes will be marked on the backside of the new and old cups. Always check these markings and verify that the sizes are matched. Incorrectly sized cups will often fit in the wheel-cylinder bore but they will not seal properly.
Brake Assembly Lube
- Assembly lube can greatly simply the wheel-cylinder overhaul process and prolong the life of the new seals.
- Clean brake fluid can be used to lubricate the wheel-cylinder bore during assembly but assembly lube is much slicker and prevents any sticking or binding and possible damage to the new cups.
Aerosol Brake Cleaner
- Commercially produced aerosol brake cleaners are designed to effectively clean brake systems while not leaving an oily residue.
- Do not use carburetor cleaner or solvent based products to clean brake system components. These products will leave a residue which could contaminate the pads/linings and cause a reduction in braking performance.