Tuesday, December 23, 2014

Change Drum Brake Footwear

Rear drum brake shoes apart tally for up to 25% of the braking force of a vehicle. With that in brains, they hurting for less maintainance than front brakes. Nevertheless coextensive everything on a vehicle, after a while, they Testament wear down and demand to be replaced. There are a parcel of inadequate components that comprise the rear drum brake shoe operation. A acceptable mindfulness and fist/finger dexterity Testament besides lift to remove and convert the rear drum brake shoes on your vehicle.


Instructions


1. Remove the hub caps of both rear wheels and crack the lug nuts loose with a lug fan wrench. Cause not loosen the nuts further all the more with the vehicle all the more on the ground.


2. Lift the rear of the vehicle with the floor jack and put the vehicle onto jack stands in a protected and secure position to facilitate the weight of the vehicle. Measure the inside diameter with a drum micrometer and compare the measurement to the discard and minimum specifications stamped on the hub face of the drum. If necessary, have the drum turned on a lathe to resurface if necessary. Auto parts stores or local repair shops will often do this for a nominal charge as long as the drum is within measurement specifications.


Contrary vehicles employment deviating style drums. Some may get retaining screws holding them to the hub. Scrutinize the hub face of the drum for any retaining devices and remove them before attempting to remove the drum. Some drums remove from the rear hub by removing a dust cap, spindle aficionado, and bearing. Other drums simply sit over the shoes and are easily removed; yet all the more, brake shoes may be adjusted upward, manufacture the Emigration of the drum aggrandized challenging, or the inside diameter of the drum may bear a rust ridge causing the drum to clutch on the shoes. De-adjusting the shoes would be accessible using a brake shoe spoon concluded the porthole located in the backing plate. Be sure to refer to a repair manual for your specific vehicle to determine how the drum is affixed to the vehicle. Apply a coat of anti-seize compound to the contact points.14. Reassemble the rear brakes by reversing the procedure. Replace the old return springs and hold-down spring and pins with new ones.


4. Inspect the inside diameter of the drums (but leave them on their respective sides to not mix them up). Check for surface cracks, scoring, or unevenness of the surface. Remove the lug nuts and wheels.3. Remove the drum. If the drum is over the measurement specifications, it needs to be replaced.


5. Inspect the wheel cylinders (both sides) with a screwdriver. Press in on the bore of the cylinder and watch to see if it returns properly. Move the rubber boots back to inspect for seepage of brake fluid. Leaking, seeping, or seized bores require the wheel cylinder to be removed. To do this, the cylinder needs to be removed from the steel brake line connection at the backing plate, and the brake system needs to be bled to purge air out after the replacement is complete.


6. Leave one side of the rear brakes together as a reference while removing and replacing the other side.


7. Inspect the shoes. Even if you're replacing the shoes, you should look at the old ones and how they're retained to the backing plate. Also note if the primary shoe (towards the front of the vehicle) is smaller than the secondary shoe. Although the shoe horns are the same size, in some vehicles, the friction material of the shoe is smaller on the primary shoe then the secondary. Inspect the new shoes to make sure you're replacing them correctly and the correct set was purchased.


8. Remove the hold-down spring on the secondary shoe (holding the parking brake actuator). Press the hold-down pin secure against the backing plate with a finger and place the brake shoe retaining spring tool onto the face of the spring and turn. The end of the pin has a wider slot that mates to the spring cap in a position that will release the pin from the cap and spring.


9. Remove the return springs using the brake shoe pliers. In most cases, there are three different return springs connecting the two shoes together. Two at the top and one at the bottom. Refer to the repair manual for any variation for your specific vehicle. Also, for vehicles with a self adjuster cable, remove this from the secondary shoe.


10. Remove the hold-down spring from the primary shoe as you did in step Eight for the secondary shoe.


11. Remove the shoes. Remove the parking brake retaining clip and pin (if applicable) from the secondary shoe. Spread the clip with a screwdriver and knock the pin out of the shoe with a hammer. Not all rear drums brakes have this option, so refer to the repair manual.


12. Remove the adjuster mechanism. Most common is a star wheel adjuster. Note the position for correct replacement. Separate the star wheel mechanism, clean it with brake clean spray, and apply a coat of anti-seize compound to the threads of the adjuster, and then set it aside. Import vehicles may use a cam adjuster. Again, remove the adjuster and clean thoroughly and make sure the cam is moving. Spray with penetrating lubricant and work it back and forth.


13. Spray the backing plate with brake clean spray and then use a piece of emery cloth to clean the surface of the shoe contact points (three per shoe). One last note on brake drums: in some cases, the brake drum hub may be rusted stuck to the rear axle hub. To separate, apply a generous amount of the penetrating oil to the junction and strike the hub face of the drum (never the side) with a hammer to "shock" the drum from the axle hub. Remove the other drum in the same fashion.


Refer to the opposite wheel for reference if needed. Repeat the procedure for the other side, again leaving the drum off on the completed side for reference.


15. Replace the drum and adjust the shoes up using the brake spoon. On the imported vehicles with the cam adjuster, the cam needs to be positioned to allow the drum to fit on and then activating the parking brake on and off repeatedly will self-adjust the shoes. For star wheel adjusters, use the spoon until you can feel the shoes dragging on the inside surface of the drum. Do not over-adjust the shoes. The drum should be able to move, with the shoes dragging enough to stop it before it turns one complete revolution.