1 Drum Brake Overhaul Roger Bortignon

2 hubless drums slide right offhubless drums slide right off  often they may have to be tapped with a hammer to free them up some imports have 2 threaded holessome imports have 2 threaded holes  install two 8mm bolts to pull the drum off drums with integral hubsdrums with integral hubs  remove dust cap  unlock retaining nut  remove washer & bearing Drum Removal

3 Drum Brake Replacement & Overhaul items that will need inspection, service or replacement include…items that will need inspection, service or replacement include…  Friction related parts  brake shoes  brake drum  Hydraulic parts  wheel cylinder & brake fluid  Hardware  emergency brake cables  brake return springs  brake adjuster

4 this is NOT a step-by-step procedurethis is NOT a step-by-step procedure drum brakes are slightly different from one car make to the nextdrum brakes are slightly different from one car make to the next experience & personal preference dictates the order for re & reexperience & personal preference dictates the order for re & re

5 Brake Shoe Removal clean brake assembly by wet washing – use a dust maskclean brake assembly by wet washing – use a dust mask  use brake washer – if on the hoist  or use spray bottle with soapy solution set to mist  do NOT use compressed air on dry brake assembly! remove upper return springsremove upper return springs

6 Brake Shoe Removal – Special Tools use brake spring pliers, not screwdrivers or general purpose pliers – easier, safer & quickeruse brake spring pliers, not screwdrivers or general purpose pliers – easier, safer & quicker

7 Brake Shoe Removal remove hold down springs (may require special tool – fig. a)remove hold down springs (may require special tool – fig. a) unhook e-brake cable (see next slide)unhook e-brake cable (see next slide) remove shoesremove shoes fig. a

8 Emergency Brake Cable Removal

9 Wheel Cylinders – what should I do with it? has the brake fluid been flushed out every 2 years?has the brake fluid been flushed out every 2 years? is it leaking?is it leaking? how old is the vehicle?how old is the vehicle? should I leave it alone?should I leave it alone? rebuild or replace?rebuild or replace?

10 Rebuilding Wheel Cylinders loosen the bleeder screw – this is importantloosen the bleeder screw – this is important cast iron cylinders can be honedcast iron cylinders can be honed  aluminum cylinders should only be cleaned & not honed use brake fluid when honinguse brake fluid when honing hone only enough to clean cylinderhone only enough to clean cylinder  (≈10 seconds) ensure there is no pitting where the cup seals slideensure there is no pitting where the cup seals slide

11 Rebuilding Wheel Cylinders replace cup seals (note diameter) & dust bootsreplace cup seals (note diameter) & dust boots use clean brake fluid or rubber lubricant to assembleuse clean brake fluid or rubber lubricant to assemble reassembly – cups on seals face inwardreassembly – cups on seals face inward

12 New Wheel Cylinders notice new brake line – olds ones often twist when you loosen themnotice new brake line – olds ones often twist when you loosen them use a flare nut wrench to loosen & install hydraulic linesuse a flare nut wrench to loosen & install hydraulic lines

13 Lubricate Shoe Support Pads use anti-seize compound on the 6 shoe support padsuse anti-seize compound on the 6 shoe support pads this will reduce/eliminate brake squealthis will reduce/eliminate brake squeal if the pads are groovedif the pads are grooved  replace backing plate, or…  mig weld grooves then grind smooth

14 Test Emergency Brake Cables apply & release e-brake while watching the cable move in & out of its’ housingapply & release e-brake while watching the cable move in & out of its’ housing any “laziness” or binding = cable needs replacingany “laziness” or binding = cable needs replacing

15 Service Brake Adjuster disassemble, clean threads & lubricate with anti-seize compounddisassemble, clean threads & lubricate with anti-seize compound some imports use a wedge to spread the shoes apartsome imports use a wedge to spread the shoes apart pay attention to the ends of the adjusterspay attention to the ends of the adjusters  ensure you understand how they are to be assembled brake adjusters are side specific – don’t mix up the left & right sides!