251-721-401ADK VW Vanagon Clutch Master Cylinder - 1980-1991

Clutch Master Cylinder – 251-721-401ADK

For owners of 1980–1991 Vanagons, the 251-721-401ADK is a vital component for drivetrain reliability. Because the Vanagon uses a hydraulic clutch system rather than a cable, the master cylinder is the heart of your shifting capability. Over time, internal bypass leaks can occur where the pedal travels to the floor but the clutch doesn't actually disengage—installing a new master cylinder solves this safety hazard immediately.

This unit is designed to work with all manual transmission Wasserboxer and Diesel engines. It is a precision-machined component that must be kept free of contaminants to ensure the internal piston moves smoothly without scoring the cylinder walls.

Detailed Vehicle Compatibility

VW Vanagon (Manual Transmission & Syncro):

• 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991

Product Highlights & Features

• Nose-Cone Location: Mounts directly to the pedal assembly under the dashboard for easy access during maintenance.

• Durable Housing: Designed to resist the high-cycle fatigue of daily driving and frequent shifting in heavy transporter applications.

• Brake Fluid Compatible: Utilizes specialized EPDM rubber components compatible with standard DOT 3 and DOT 4 fluids.

Technical Specifications

• Part Number: 251-721-401ADK

• Bore Size: 19.05mm

• Material: Heavy-duty metal housing with rubber dust boot

• Application: 1.6L Diesel, 1.9L, and 2.1L engines

Installation & Maintenance Tips

• The "Vanagon Lean": Bleeding the Vanagon clutch can be tricky because the master cylinder sits higher than the slave. Some owners find it helpful to jack up the front of the van or use a pressure bleeder to ensure all air is removed from the system.

• Check the Feed Hose: When replacing the master cylinder, inspect the Blue Feed Hose that runs from the reservoir. These often become brittle and can leak fluid onto your wiring or carpet.

• System Match: It is highly recommended to replace the Clutch Slave Cylinder at the same time. If the master has failed due to age, the slave is likely in a similar condition and will often fail shortly after the master is replaced.

1130600600

721215003

251721401ADK