Fuel Pump, Alternator Style For VW Aircooled, Premium

OVERVIEW

When it comes to maintaining the heartbeat of your vintage Volkswagen, settling for anything less than OEM-grade reliability is a risk no enthusiast should take. The Brosol Premium Alternator-Style Mechanical Fuel Pump is widely recognized by air-cooled purists and professional builders as the gold standard for Type 1 engines. Unlike generic reproductions that often suffer from internal diaphragm failure or inconsistent pressure, this Brosol unit is engineered to withstand the rigors of modern ethanol-blended fuels while providing the precise flow required for stock and mild performance carburetors. Whether you are finishing a concourse restoration or refreshing your daily driver, this pump ensures that your fuel delivery remains consistent, preventing the vapor lock and starvation issues that plague lesser components.

The transition from the traditional generator to the high-output alternator in the early 1970s required a significant design change in the fuel pump housing. Because the alternator is physically larger in diameter at the pulley end, a standard "straight" fuel pump will not clear the casing. This premium Brosol pump features the specific angled body designed to tuck neatly away from the alternator, providing the necessary clearance for a trouble-free installation. This is the correct choice for 1973 and later Beetles and Karmann Ghias, but it is also the mandatory upgrade for any earlier engine that has been converted from a generator to an alternator charging system. Precision-cast and factory-tested, this pump embodies the "buy it once, install it right" philosophy that Appletree Auto stands behind.

FITMENT

This fuel pump is designed for Type 1 based air-cooled engines equipped with an alternator. Please verify your charging system style and push rod length before ordering.

• VW Beetle: 1973 - 1974 (Factory Alternator Models)
• VW Beetle: 1954 - 1972 (If converted to an Alternator system)
• VW Karmann Ghia: 1973 - 1974 (Factory Alternator Models)
• VW Karmann Ghia: 1956 - 1972 (If converted to an Alternator system)
• VW Super Beetle: 1973 - 1974 (Factory Alternator Models)
• VW Thing (Type 181): 1973 - 1974
• Custom Applications: Any Sand Rail, Dune Buggy, or Baja Bug utilizing a 1600cc-based Type 1 engine with an alternator setup.

SPECS

• Brand: Brosol (Premium Quality)
• Part Number: 113-127-025GP
• Pump Style: Mechanical (Diaphragm Driven)
• Application: Alternator-specific angled housing
• Push Rod Required: 100mm / 4-inch (Short Style)
• Fuel Inlet/Outlet Size: Standard 5mm / 1/4-inch slip-on
• Body Material: High-grade die-cast zinc alloy
• Internal Components: Ethanol-resistant diaphragm and seals
• Included Accessories: Two (2) base gaskets

PRO TIPS

1. Verify Your Push Rod Length Before Installation

One of the most common mistakes in VW engine assembly is mixing up fuel pump push rods. This alternator-style pump REQUIRES the "short" 100mm (approximately 4-inch) push rod. If you are converting from a generator-style pump (which uses a 108mm rod) to this alternator-style pump, you MUST swap the push rod as well. Using the longer rod with this pump will cause the internal lever to bind, likely snapping the rod, destroying the pump diaphragm, or even damaging your engine''s internal drive cam. Always rotate the engine by hand after installation to ensure there is no mechanical interference before you turn the key.

2. Inspect the Phenolic Spacer Block

The plastic (phenolic) spacer block that sits between the fuel pump and the engine case is a critical thermal barrier. Over time, these blocks can become brittle, crack, or warp, leading to persistent oil leaks or vacuum issues. When installing your new Brosol pump, carefully inspect your spacer for any hairline fractures. We highly recommend applying a very thin smear of high-quality gasket sealant to both sides of the new gaskets. Be careful not to over-torque the two 13mm mounting nuts; over-tightening is the leading cause of cracked spacers and distorted pump flanges.

3. Proper Lubrication and Priming

Before you bolt the pump down, apply a small dab of high-temperature wheel bearing grease to both ends of the fuel pump push rod and the contact point on the pump''s internal lever. This prevents "dry starts" and premature wear on the hardened surfaces. Additionally, if your car has been sitting for a long time, the fuel lines may be dry. To save wear and tear on your starter and battery, you can manually prime the pump or use a small amount of fuel in the carburetor bowl to help the engine fire up quickly, allowing the mechanical pump to take over the suction process immediately.