DIY Network

4-Wheel ATV: Front-Brakes Service From "Weekend Mechanic" episode WKM-313

	Bruce and Roger begin the front-brake service on this Honda 4-wheeler.
	The replacement brake shoes.

In this segment of DIY's Weekend Mechanic host Bruce Bonebrake performs front-brake service on a 4-wheel all-terrain vehicle, replacing the front-brake shoes and ensuring a watertight seal to protect the drums.

Materials:

In addition to standard auto-mechanic's tools (wrenches, ratchets, extenders, screwdrivers, nut-drivers, etc.), some of the specialty tools that will be needed for these projects include hydraulic bleed pump, brake-cleaner spray, brake grease, waterproof bearing-grease, needle-nosed pliers, high-speed drill, hole saw, torque wrench and an air-compressor and set of pneumatic tools.

DIY Difficulty Rating for the Project: This routine maintenance shown in this episode should be no problem for the experienced weekend mechanic. The brake work, wiring and winch addition are a little more challenging. Some experience with motorcycle maintenance and repair would be a plus. Overall, we gave these projects a difficulty rating of 2 on a 5-point intermediate-level scale. It took us about 8 hours to finish this job. Allow yourself a full weekend to complete this project properly.

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Front-Brakes Service

• To begin the front-end brake work, carefully jack the 4-wheeler and make sure that it is safely supported on jack stands.

• Remove the front wheels and tires using an air-wrench.

• With the wheels off, remove the cotter pin (figure A) at the right-front wheel to access the brake shoes. The cotter pin should later be replaced with a new pin.

  Important: Never re-use an old cotter pin that has already been used in an axle. A worn cotter pin could brake and cause serious problems.

• Use the air-wrench to loosen and remove the castel nut from the axle (figure B).

  Figure B

  Figure A

  
  

• With the castel nut removed, carefully slide the brake drum off the axle (figure C), taking care to protect the watertight seal and avoid scratching the drum.

• With the drum removed, the brake shoes and hydraulic wheel cylinders can be inspected (figure D). Individual adjustments for each shoe can be made on the end of each cylinder.

  Figure C

  Figure D

  
  

• To change out the old brake-shoes, two sets of springs will first need to be removed. First, use needle-nosed pliers remove the two tension springs between the shoes (figure E).

• The second set of springs -- the hold-down springs at the center of each -- may be more difficult to remove. Compress the springs while using the needle-nosed pliers to turn the spring-post at the center of each spring to release it (figure F).

  Figure E

  Figure F

  
  

• Once the springs have been removed, the brake shoes should come right off. With the old shoes removed, use spray brake-cleaner to spray down the brake backing-plate to remove residue and dirt (figure G).

• Use a clean shop rag to wipe down the backing plate to remove residual spray, grease or dirt.

• Apply brake-shoe grease on the plate at the locations where the shoes move (figure H).

  Figure G

  Figure H

  
  

  Figure I

• Position the new shoe in position and apply the hold-down spring (figure I). The spring must be compressed while the spring-post is turned 90 degrees to catch and secure the spring.

  Note: If the hold-down springs seem easy to put on, they probably are worn out and should be replaced.

• Repeat the procedure for the hold-down spring on the other brake shoe.

• Reinstall the original tension springs on each new shoe.
  

• With the new brake shoes and springs in place, check and lubricate the O-ring on the brake spindle. This O-ring helps keep water out of the brake area. If it is damaged, it should be replaced, and the replacement well lubricated.

• Use spray brake-cleaner to clean dirt and residue from the brake drum (figure J), and re-grease the seal around the outer edge of the drum.

  Note: Use a waterproof wheel-bearing grease on the brake-drum seal.

• Slide the drum back onto the axle (figure K), screw on the castel nut and tighten down the nut to the proper torque-specs. (For this particular ATV, the castel nut was torque-tightened to 50 foot-pounds.)

• Install a new cotter-pin and bend it up to secure the nut.

  Figure J

  Figure K

  
  

In the segment that follows, the front brakes are serviced and the brakes are bled.

Important: Included in this segment are the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most vehicles. With any particular vehicle, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of repair-kit you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.

Safety Alert: As a standard safety precaution, don't rely solely on a jack to support the weight of a vehicle. When using a jack to access or work beneath a vehicle, always use jack stands for support. Make sure that the jack and stands that you use are rated for the weight and type of your vehicle.

Safety Alert: Always dispose of automotive fluids (antifreeze, motor oil, transmission fluid, etc.) and other toxic substances responsibly. Most auto center offer recycling of automotive fluids.

RESOURCES :

The Complete Idiot's Guide to Motorcycles
ISBN: 0028624165
Author: editors of Motorcyclist magazine

Warn Industries Inc.
Provided the winch installed on the ATV in WKM, episode 313.
Website: www.warn.com