Residual Pressure Valve Disc Brakes, 2LB

OVERVIEW

When you are building a custom air-cooled VW or a high-performance dune buggy, achieving a firm, consistent brake pedal is often the difference between a confident drive and a white-knuckle experience. The EMPI 2LB Residual Pressure Valve is an essential component for any disc brake system where the master cylinder is mounted at or below the level of the brake calipers. In many custom chassis, sand rails, and lowered Beetles, gravity tends to pull brake fluid back toward the master cylinder when the vehicle is at rest. This creates a "dead spot" in the pedal travel because the first half of your stroke is spent simply moving fluid back into the calipers to reset the pads against the rotors. By maintaining a constant 2 pounds of residual pressure in the lines, this valve ensures that your brake pads remain in close proximity to the rotor, providing instantaneous engagement the moment you touch the pedal.

Crafted with the precision that EMPI is known for, this valve is designed to withstand the harsh environments of both off-road racing and daily street use. It features a high-quality anodized finish for superior corrosion resistance and is color-coded for easy identification in your brake plumbing layout. For the air-cooled enthusiast, this is the professional solution to the common "spongy pedal" syndrome found in disc brake conversions. Whether you are running a classic Type 1 Beetle, a rugged Manx-style buggy, or a dedicated drag car, integrating this 2lb valve into your hydraulic system eliminates the need for "pumping the brakes" and ensures that your stopping power is always ready when you need it most. It''s a small investment that yields a massive improvement in driver feedback and overall vehicle safety.

FITMENT

This residual pressure valve is a universal performance component designed for hydraulic brake systems. It is most commonly used in the following air-cooled VW applications and custom builds:

• VW Beetle (All Years): Ideal for disc brake conversions and custom floor-pan builds.
• VW Karmann Ghia: Essential for upgraded disc brake systems and performance builds.
• VW Type 3 (Squareback, Fastback, Notchback): Perfect for maintaining pressure in custom hydraulic setups.
• VW Thing (Type 181): A must-have for off-roaders with disc brake upgrades.
• Dune Buggies & Sand Rails: Specifically required when the master cylinder is mounted low in the chassis.
• Custom Trikes & Hot Rods: Compatible with any system utilizing 1/8 inch NPT plumbing.
• Baja Bugs: Provides consistent braking performance over rough terrain.

SPECS

Every detail of the EMPI 870-2 valve is engineered for reliability and high-flow performance. Here are the technical specifications:

• Pressure Rating: 2 LB (Designed specifically for Disc Brake applications).
• Inlet Port: 1/8 inch NPT Male.
• Outlet Port: 1/8 inch NPT Female.
• Construction Material: High-grade billet aluminum.
• Finish: Anodized for durability and chemical resistance against brake fluid.
• Function: Prevents fluid drain-back and maintains pad-to-rotor contact.
• Part Number: 870-2 (EMPI).
• Compatibility: Compatible with DOT 3, DOT 4, and DOT 5.1 brake fluids.

PRO TIPS

1. Correct Valve Selection is Critical

One of the most common mistakes in VW brake plumbing is using the wrong pressure valve. This 2lb valve is strictly for disc brakes. If you were to use a 10lb valve (intended for drum brakes) on a disc brake system, the 10lbs of pressure would be enough to cause the calipers to stay partially engaged, leading to overheated rotors, premature pad wear, and "brake drag." Always verify that you are installing the blue-coded 2lb valve for your discs and the red-coded 10lb valve for your drums. If you have a disc/drum combo, you will need one of each installed in their respective lines.

2. Master Cylinder Orientation Matters

You only need a residual pressure valve if your master cylinder is located lower than your brake calipers. In a stock VW Beetle, the master cylinder is relatively low, but in many sand rails and tube-chassis buggies, it sits significantly lower than the wheel cylinders or calipers. Even if your system feels "okay" now, adding this valve will often "crispen up" the pedal feel significantly. When installing, ensure the valve is located as close to the master cylinder as possible in the brake line to maximize its effectiveness in holding the column of fluid steady.

3. Plumbing and Thread Sealant Precautions

The 1/8 inch NPT threads on this valve are tapered, which means they seal by thread interference. When installing your fittings, use a very small amount of Teflon tape or a specialized liquid thread sealant designed for hydraulic systems. However, be extremely careful not to get any sealant inside the valve itself, as even a tiny fragment can clog the internal spring and check-ball mechanism, causing the valve to fail or stick. If you are adapting this to standard VW M10x1.0 metric brake lines, you will need NPT-to-Metric adapters, which are readily available at Appletree Auto to ensure a leak-free installation.