Residual Pressure Valve Disc Brakes, 2 lb Metric

OVERVIEW

In the world of custom air-cooled VWs, sand rails, and off-road buggies, achieving a firm and consistent brake pedal is often the difference between a controlled stop and a heart-pounding near-miss. The EMPI 2 lb Metric Residual Pressure Valve is an essential component designed specifically for disc brake systems where the master cylinder is mounted lower than the brake calipers. Without this valve, brake fluid naturally tends to gravity-drain back into the reservoir, causing the caliper pistons to retract further than necessary. This retraction creates a "low pedal" or "spongy" feel, forcing the driver to "pump" the brakes to build enough pressure to engage the pads. By maintaining a constant 2 PSI of residual pressure in the lines, this valve ensures that your brake pads remain in close proximity to the rotors, providing instantaneous engagement and a professional-grade pedal feel the moment you tap the brakes.

Crafted with the precision that Appletree Auto customers demand, this valve features a high-quality billet aluminum body with a distinct blue anodized finish for easy identificationblue always signifies a 2 lb valve for disc applications, whereas red denotes a 10 lb valve for drums. The metric M10x1.0 female threads on both ends are designed for a seamless, leak-free "bubble flare" connection, which is the standard for most late-model air-cooled VW brake lines and master cylinders. Whether you are building a high-performance Baja Bug, a show-winning Karmann Ghia, or a rugged tube-chassis sand rail, integrating this residual pressure valve into your hydraulic system is a critical step in optimizing safety and performance. Don''t settle for a soft pedal when a simple, robust solution like the EMPI 17-2928-0 is available to keep your braking system primed and ready for action.

FITMENT

• VW Beetle (Standard & Super): All years converted to front or rear disc brakes.
• VW Karmann Ghia: 1956-1974 equipped with disc brake upgrades.
• VW Type 3 (Squareback, Fastback, Notchback): All years with disc brake conversions.
• VW Thing (Type 181): 1973-1974 utilizing disc brake setups.
• VW Bus (Type 2): 1950-1979 models running custom disc brake configurations.
• Sand Rails & Dune Buggies: All custom tube-chassis applications using metric M10x1.0 plumbing.
• Baja Bugs: Ideal for off-road builds where the master cylinder is relocated or mounted low in the chassis.
• Meyers Manx: Fits all classic and modern fiberglass buggy builds with disc brakes.

SPECS

• Product Name: EMPI Residual Pressure Valve
• Part Number: 17-2928-0
• Pressure Rating: 2 PSI (Specifically for Disc Brake Applications)
• Inlet Thread: M10 x 1.0 Female (Metric Bubble Flare)
• Outlet Thread: M10 x 1.0 Female (Metric Bubble Flare)
• Material: High-Strength Billet Aluminum
• Finish: Blue Anodized for corrosion resistance and easy identification
• Length: Approximately 2.5 inches
• Function: Prevents fluid drain-back and maintains pad-to-rotor proximity

PRO TIPS

1. Proper Flow Orientation is Critical

One of the most common mistakes during installation is mounting the valve backward. These valves are directional and are designed to allow full fluid flow toward the calipers while maintaining the rated 2 PSI of back-pressure toward the master cylinder. Always look for the flow arrow stamped on the body of the valve. The arrow must point away from the master cylinder and toward the brake calipers. If installed backward, you will experience a "locked-on" brake scenario where the fluid cannot return to the master cylinder, causing the brakes to drag or seize entirely. Always double-check the arrow direction before finalizing your hard lines.

2. Mount the Valve as Close to the Master Cylinder as Possible

For maximum efficiency, the residual pressure valve should be installed in the brake line as close to the master cylinder as physically possible. This placement ensures that the entire column of fluid between the master cylinder and the calipers is held under that light 2 PSI of pressure. This is especially vital in sand rails or mid-engine buggies where the brake lines may have long runs or complex routing. By keeping the valve near the source of the pressure, you minimize the volume of fluid that can potentially fluctuate, resulting in the firmest and most consistent pedal response possible.

3. Never Mix Disc and Drum Valve Ratings

It is imperative to remember that this 2 lb (Blue) valve is strictly for disc brake circuits. Disc brakes require very little pressure to keep the pads seated near the rotor. If you were to accidentally install a 10 lb (Red) drum brake valve on a disc system, the constant 10 PSI would be strong enough to actually engage the calipers, leading to excessive heat, premature pad wear, and warped rotors. Conversely, using this 2 lb valve on a drum system will not provide enough pressure to overcome the heavy return springs found in drum brakes, leading to a dangerously low pedal. Always match the valve color to your brake type: Blue for Disc, Red for Drum.