1. Introduction
This manual provides essential instructions for the proper installation, operation, and maintenance of the Dexter K71-165-00 hydraulic brake assembly. This brake is designed for a single wheel on 8K, 9K, and 10KGD trailer axles. Please read this manual thoroughly before attempting any installation or service to ensure safety and optimal performance.
2. Product Overview
The Dexter K71-165-00 is a 12-1/4 inch by 3-3/8 inch hydraulic drum brake assembly. It is specifically designed for the left-hand (driver's side) of a trailer. This assembly is compatible with Dexter 8K, 9K, and 10KGD axles that utilize hydraulic drum brakes.
Figure 1: Dexter K71-165-00 Hydraulic Brake Assembly. This image displays the Dexter K71-165-00 hydraulic brake assembly, designed for a single wheel. It includes the brake shoes, backing plate, and associated hardware such as nuts and adjustment plates. The brake shoes feature a friction material surface and are curved to fit within a drum. The assembly is for the left-hand (driver's side) of the trailer.
Key features and compatibility:
- Fits Dexter 8K, 9K, and 10KGD Axles with Hydraulic Drum Brakes.
- Dimensions: 12-1/4 inches diameter x 3-3/8 inches width.
- Designed for the left-hand (driver's side) wheel.
- For complete 8K assembly, refer to part numbers K23-402-00 and K23-403-00.
- For complete 9-10K GD assembly, refer to part numbers K23-410-00 and K23-411-00.
3. Safety Information
Always prioritize safety when working with trailer brakes. Failure to follow these safety guidelines can result in serious injury or property damage.
- Professional Installation Recommended: If you are not experienced with trailer brake systems, it is highly recommended to have a qualified technician perform the installation.
- Personal Protective Equipment (PPE): Always wear safety glasses, gloves, and appropriate protective clothing.
- Vehicle Support: Ensure the trailer is securely supported on jack stands on a level surface before beginning any work. Never rely solely on a jack.
- Brake Fluid: Hydraulic brake fluid can be corrosive. Avoid contact with skin and painted surfaces. Dispose of used fluid responsibly.
- Torque Specifications: Adhere to all torque specifications provided by the axle or trailer manufacturer for fasteners.
- System Bleeding: Proper bleeding of the hydraulic system is critical for brake function. Air in the lines will result in brake failure.
4. Setup and Installation
This section outlines the general steps for installing the Dexter K71-165-00 hydraulic brake assembly. Specific procedures may vary based on your trailer model and axle type. Consult your trailer's service manual for detailed instructions.
- Prepare the Trailer:
- Park the trailer on a level surface.
- Chock the wheels that will remain on the ground.
- Raise the trailer and support the axle securely with jack stands.
- Remove the wheel and tire assembly.
- Remove Old Brake Assembly (if applicable):
- Disconnect the hydraulic brake line from the old backing plate. Be prepared for brake fluid leakage and have a drain pan ready.
- Remove the nuts or bolts securing the old brake backing plate to the axle flange.
- Carefully remove the old brake assembly.
- Install New Brake Assembly:
- Ensure the new K71-165-00 assembly is for the left-hand (driver's side) of the trailer.
- Position the new backing plate onto the axle flange, aligning the mounting holes.
- Secure the backing plate with the appropriate nuts/bolts. Torque to the manufacturer's specifications.
- Connect the hydraulic brake line to the new brake cylinder on the backing plate. Use a new copper washer if required and tighten securely.
- Install Drum and Wheel:
- Reinstall the brake drum over the new brake shoes.
- Adjust the brake shoes as necessary (refer to Section 5.1 for initial adjustment).
- Reinstall the wheel and tire assembly. Torque lug nuts to manufacturer specifications.
- Bleed the Hydraulic System:
- Bleed the entire hydraulic brake system to remove any air. Start with the wheel furthest from the master cylinder and work towards the closest.
- Ensure the master cylinder reservoir is kept full of the correct type of brake fluid during the bleeding process.
- A firm brake pedal/lever indicates successful bleeding.
- Test Brakes:
- Before road use, perform static and low-speed brake tests in a safe, open area.
- Check for proper brake engagement and release, and ensure there are no fluid leaks.
5. Operation and Adjustment
The Dexter K71-165-00 hydraulic brake operates by converting hydraulic pressure from the master cylinder into mechanical force to press the brake shoes against the inside of the brake drum, creating friction and slowing the trailer.
5.1 Initial Brake Adjustment
Proper adjustment is crucial for effective braking. New brakes require an initial adjustment and periodic checks.
- With the wheel and drum installed, locate the adjustment slot on the bottom of the backing plate.
- Using a brake spoon or flat-head screwdriver, rotate the star wheel adjuster until the brake shoes lightly drag against the drum.
- Back off the adjuster approximately 8 to 10 clicks, or until the wheel rotates freely with minimal drag.
- Repeat for all brake assemblies on the trailer.
Note: After the first 200 miles of operation, re-check and adjust the brakes as the shoes seat into the drums.
6. Maintenance
Regular maintenance ensures the longevity and safe operation of your hydraulic brake system.
- Brake Fluid Level: Check the master cylinder fluid level regularly (e.g., before each trip or every 3 months). Top off with the recommended brake fluid type.
- Fluid Leaks: Inspect all brake lines, connections, and wheel cylinders for any signs of fluid leaks. Address leaks immediately.
- Brake Shoe Wear: Periodically remove the brake drum to inspect the brake shoes for wear. Replace shoes if the friction material is worn down to the rivets or if uneven wear is observed.
- Drum Condition: Inspect brake drums for scoring, cracks, or excessive wear. Replace or machine drums as needed.
- Wheel Bearings: Ensure wheel bearings are properly lubricated and adjusted according to axle manufacturer specifications.
- General Inspection: Annually, or every 12,000 miles, perform a thorough inspection of the entire brake system, including springs, adjusters, and hardware.
7. Troubleshooting
This section addresses common issues you might encounter with your hydraulic brake system.
| Problem | Possible Cause | Solution |
|---|---|---|
| Soft or Spongy Pedal | Air in hydraulic lines; low brake fluid; faulty master cylinder. | Bleed the brake system; check and fill master cylinder; inspect/replace master cylinder. |
| Poor Braking Performance | Improper brake adjustment; worn brake shoes/drums; contaminated brake shoes; air in lines. | Adjust brakes; inspect/replace shoes/drums; clean or replace contaminated shoes; bleed system. |
| Brakes Dragging | Over-adjusted brakes; seized wheel cylinder; restricted brake line. | Back off brake adjustment; inspect/replace wheel cylinder; check brake lines for kinks or blockages. |
| Fluid Leaks | Loose fittings; damaged brake line; leaking wheel cylinder. | Tighten fittings; replace damaged lines; replace leaking wheel cylinder. |
8. Specifications
| Attribute | Detail |
|---|---|
| Model Number | K71-165-00 |
| Brake Type | Hydraulic Drum Brake |
| Brake Dimensions | 12-1/4 inches (diameter) x 3-3/8 inches (width) |
| Axle Compatibility | Dexter 8K, 9K, 10KGD Axles |
| Side Specificity | Left-hand (Driver's Side) |
| Manufacturer | Dexter |
| Item Weight | Approximately 15 pounds |
| Product Dimensions | 12 x 10 x 6 inches (packaging/shipping dimensions) |
9. Warranty Information
Specific warranty details for the Dexter K71-165-00 hydraulic brake assembly are typically provided by the manufacturer, Dexter, or the point of purchase. Please retain your proof of purchase. For detailed warranty terms and conditions, refer to the documentation included with your product or contact Dexter customer support directly.
10. Support
For technical assistance, troubleshooting beyond this manual, or to inquire about replacement parts, please contact the manufacturer or your authorized dealer. When contacting support, have your product model number (K71-165-00) and purchase information readily available.
Manufacturer: Dexter Axle Company
Website: www.dexteraxle.com
