1. Introducció
This manual provides essential information for the Dorman W51081 Rear Drum Brake Wheel Cylinder. This component is designed as a direct replacement for the original wheel cylinder in specific vehicle applications, ensuring proper fit, function, and performance within the vehicle's drum brake system. Adherence to these instructions is crucial for safe and effective operation.
2. Producte acabatview
The Dorman W51081 is a critical component of a vehicle's drum brake system. It converts hydraulic pressure from the master cylinder into mechanical force to push the brake shoes against the drum, initiating braking.
Característiques principals:
- Substitució ideal: Dissenyat específicament per ser una coincidència directa amb el cilindre de roda de fre de tambor original en vehicles particulars.
- Cost-Effective Fix: Replacement of the cylinder while servicing drum brakes is often the most efficient way to ensure brake performance.
- Materials de qualitat: Manufactured with high-quality EPDM rubber cups and boots for long-lasting performance and resistance to brake fluid.
- Professionally Tested: Wheel cylinder bores are surface-tested to ensure an optimum sealing surface for the pressure cups, preventing leaks and ensuring consistent braking.

Figura 1: Frontal view of the Dorman W51081 Rear Drum Brake Wheel Cylinder, showing the main body, bleeder screw, and mounting points.

Figura 2: Pro lateralfile of the Dorman W51081 Rear Drum Brake Wheel Cylinder, highlighting its cylindrical shape and protective rubber boots.

Figura 3: Angle view of the Dorman W51081 Rear Drum Brake Wheel Cylinder, focusing on one of the rubber boots and the overall construction.
3. Compatibilitat del vehicle
This Dorman W51081 Rear Drum Brake Wheel Cylinder is compatible with select vehicle models. To ensure proper fitment for your specific vehicle, it is crucial to verify compatibility using a vehicle fitment tool or by consulting your vehicle's service manual.
Refer to the following OEM Part Numbers for cross-referencing:
Números de peça OEM: 134.62001; 135.62001; 172-1219; 18E1034; 18E56; 2037048; 33469; 51081; 784-36001; 84-36001; 84-50001; F51081; W-82001; W906224; WC13469; WC37048; WC51081; 18004880; 18004890; 18029236; 18060028; 5465580; 5469302; 8124565; 8129723; J8126742; J8129723
4. Instruccions d'instal·lació
Safety Warning: Brake system work requires specialized knowledge and tools. Improper installation can lead to brake failure, serious injury, or death. If you are not confident in your ability to perform this repair, seek assistance from a qualified automotive technician.
Required Tools and Materials (Typical):
- Gato i suports per a vehicles
- Clau de rodes de roda
- New brake fluid (compatible with your vehicle's specifications)
- Line wrenches (for brake lines)
- Bleeder wrench
- Drain pan for brake fluid
- Shop rags or towels
- Guants i ulleres de seguretat
- Clau dinamométrica
Passos generals d'instal·lació:
- Preparació: Park the vehicle on a level, firm surface. Engage the parking brake and place wheel chocks behind the wheels that will remain on the ground. Loosen the lug nuts on the wheel to be serviced, but do not remove them yet.
- Vehicle elevador: Safely lift the vehicle using a jack and secure it firmly with jack stands. Ensure the vehicle is stable before proceeding. Remove the wheel.
- Remove Brake Drum: Carefully remove the brake drum. This may require releasing the automatic brake shoe adjuster through an access hole in the backing plate. Consult your vehicle's service manual for specific procedures.
- Disconnect Brake Line: Place a drain pan beneath the wheel cylinder to catch leaking brake fluid. Using a line wrench, carefully disconnect the brake line from the old wheel cylinder. Be prepared for brake fluid leakage.
- Remove Old Wheel Cylinder: Remove the mounting bolts that secure the wheel cylinder to the backing plate. Remove the old wheel cylinder from the vehicle.
- Install New Wheel Cylinder: Position the new Dorman W51081 wheel cylinder onto the backing plate. Secure it with the mounting bolts, tightening them to the vehicle manufacturer's specified torque.
- Reconnect Brake Line: Carefully reconnect the brake line to the new wheel cylinder. Ensure a snug fit to prevent leaks, but do not overtighten.
- Remuntar els frens: Reinstall the brake shoes and all associated hardware, ensuring all components are correctly seated and adjusted according to your vehicle's service manual. Reinstall the brake drum.
- Sistema de frens de purga: This is a critical step to remove all air from the brake lines. Start with the wheel cylinder furthest from the master cylinder and work your way closer. Follow your vehicle's specific bleeding procedure, which typically involves having an assistant pump the brake pedal while you open and close the bleeder screw. Ensure the master cylinder reservoir remains full throughout the process.
- Comprovacions finals: Reinstall the wheel, lower the vehicle, and tighten lug nuts to the manufacturer's specified torque. Pump the brake pedal several times to build pressure. Check for any brake fluid leaks around the new wheel cylinder and brake lines. Test drive the vehicle in a safe, open area at low speed to confirm proper brake function before normal operation.
5. Manteniment
Regular inspection of your vehicle's brake system, including the wheel cylinders, is crucial for safety and performance. Adhere to your vehicle manufacturer's recommended maintenance schedule.
- Nivell del líquid de frens: Regularly check the brake fluid level in the master cylinder reservoir. A low fluid level can indicate a leak in the system or worn brake pads.
- Estat del líquid de frens: Brake fluid should be clear or slightly amber. If it appears dark, cloudy, or contaminated, it may need to be flushed and replaced according to your vehicle manufacturer's recommendations.
- Inspecció de fuites: Periodically inspect the wheel cylinders for any signs of brake fluid leaks, especially around the rubber boots. Any visible leakage indicates a failing wheel cylinder that requires immediate replacement.
- Rendiment dels frens: Pay attention to any changes in brake pedal feel, such as sponginess, excessive travel, or pulling to one side, which could indicate air in the system, a failing component, or uneven brake wear.
6. Resolució de problemes comuns
| Símptoma | Causa possible | Solució |
|---|---|---|
| Pedal de fre esponjós | Air in brake lines; Leaking wheel cylinder | Bleed the brake system thoroughly; Inspect and replace wheel cylinder if leaking. |
| Low Brake Fluid Level | Brake fluid leak from wheel cylinder or other components | Inspect the entire brake system for leaks, repair or replace components as needed. |
| Brake Dragging / Uneven Braking | Sticking or seized wheel cylinder piston | Inspect wheel cylinder for proper movement; replace if pistons are seized or corroded. |
| Fluid Leak at Wheel | Failed wheel cylinder seal or boot | Replace the wheel cylinder immediately. |
7. Especificacions del producte
- Marca: Dorman
- Model: W51081
- Pes de l'article: 1.1 lliures
- Dimensions del producte: 4.2 x 2.9 x 2.7 polzades
- Exterior: Mecanitzat
- Número de peça del fabricant: W51081
- Números de peça OEM: 134.62001; 135.62001; 172-1219; 18E1034; 18E56; 2037048; 33469; 51081; 784-36001; 84-36001; 84-50001; F51081; W-82001; W906224; WC13469; WC37048; WC51081; 18004880; 18004890; 18029236; 18060028; 5465580; 5469302; 8124565; 8129723; J8126742; J8129723
8. Garantia i Suport
For specific warranty information and technical support regarding the Dorman W51081 Rear Drum Brake Wheel Cylinder, please refer to the official Dorman website or contact Dorman customer service directly. It is recommended to keep your purchase receipt for any warranty claims.
You can visit the Dorman Store for more products and information: Botiga oficial de Dorman.