Porsche Transmission Breather – 911/914/930 (1970–1976) 904-301-071-00-OEM | OEM Gearbox Vent Valve

Maintain smooth and reliable gearbox performance with the Porsche Transmission Breather (904-301-071-00). Designed for Porsche 911, 914, and 930 models produced from 1970 to 1976, this OEM breather valve ensures proper air pressure balance inside the transmission housing. By allowing controlled airflow, it prevents vacuum buildup, fluid leakage, and seal stress under high operating temperatures.

Crafted from heat-resistant aluminum and built to Porsche’s exact specifications, this breather is essential for transmission longevity and consistent oil circulation. Ideal for restorations, maintenance, or gearbox rebuilds, it guarantees factory-correct fit and long-term reliability.

Key Features

• OEM Porsche Engineering – Manufactured to Porsche factory specifications for perfect fitment and performance

• Regulates Transmission Pressure – Balances internal air pressure to prevent leaks and seal damage

• Prevents Fluid Loss – Allows air exchange while maintaining proper lubrication levels

• Durable Construction – Made from corrosion- and heat-resistant materials for long-term reliability

• Direct Fit for Porsche 911, 914, and 930 (1970–1976) – Simple installation with no modification required

• Improves Gearbox Longevity – Reduces internal stress, ensuring smoother operation and longer service life

• Essential for Restorations and Rebuilds – Recommended during transmission overhauls or maintenance services

Frequently Asked Questions (FAQ)

1. What does the Porsche Transmission Breather do?
The breather maintains proper internal air pressure within the gearbox, preventing pressure buildup that can cause oil leaks or seal failure.

2. Which Porsche models use this breather?
It fits Porsche 911, 914, and 930 models manufactured between 1970 and 1976.

3. What happens if the transmission breather is blocked or damaged?
A blocked or failing breather can cause internal pressure buildup, leading to fluid leaks, poor lubrication, and potential transmission seal failure.

4. Is this part OEM quality?
Yes, this is an OEM-grade Porsche component designed to meet or exceed factory standards for reliability and fitment.

5. Should I replace the breather during a gearbox rebuild?
Yes, replacing the breather during a transmission rebuild or fluid service helps maintain proper pressure balance and extends gearbox life.