Water Drain Hose. Porsche 911 / 930 1976–89 › 91157122400

Genuine Porsche water drain hose for selected Porsche 911 and 930 fresh-air ventilation assemblies. It carries collected water away from the fresh-air inlet box through the intended drainage route.

Fits:

• Porsche 911 1976–1977 2.7L / 1976–77 3.0 Carrera
• Porsche 911 1978–1983 3.0L / SC
• Porsche 911 1984–1986 3.2L
• Porsche 911 1987–1989 3.2L G50
• Porsche 911 1975–1977 3.0L Turbo (930)
• Porsche 911 1978–1989 3.3L Turbo (930)

Diagram Ref No 4

Check fitment for your specific vehicle (model, year, engine) before ordering. Confirm the installation position and required hose length against the original arrangement.

What Is This Part?
This hose forms part of the water drainage arrangement associated with the fresh-air inlet box and ventilation housing. Water entering the intake area needs an unobstructed route away rather than collecting beside the blower and surrounding bodywork. The hose provides that route when correctly connected and seated. Different installations use different lengths, so matching the vehicle's existing arrangement matters as well as checking the part reference.

What Does This Part Do?

• Provides a drainage outlet: Carries water collected in the fresh-air intake area away from the inlet box.
• Directs moisture: Keeps drainage following its intended route rather than escaping through a damaged or disconnected hose.
• Limits standing water: An unobstructed hose allows collected water to leave the ventilation assembly.
• Completes the drainage arrangement: Works with the inlet box and associated connections in the applicable installation.

Why Replace This Part?
A split, hardened or damaged hose may leak before water reaches its intended outlet. A hose that has become loose or disconnected can also allow water to collect around the ventilation housing. Replacement is appropriate where deterioration prevents the hose from seating correctly or carrying water without leakage.

Slow drainage does not automatically mean a new hose is needed. Inspect for debris and check the connections first; an intact hose may only need clearing and refitting. During ventilation repairs, check the hose before reassembly rather than replacing it solely because the inlet box has been removed.

When to Replace This Part?

• Visible damage: Splits, cracks or damaged ends allow water to escape.
• Poor seating: Hardened or distorted ends no longer remain correctly connected.
• Missing hose: The original drainage route is incomplete.
• Persistent restriction: Drainage remains slow after checking for removable debris and incorrect routing.
• Water accumulation: Standing water or dampness beside the inlet box warrants inspection of the hose and surrounding assembly.
• Retained moisture: Musty smells alongside visible dampness are a reason to investigate drainage, not proof that this hose alone is faulty.

Where Is This Part Fitted?
Location: At the fresh-air inlet box within the front ventilation and heating assembly, connected to its water drainage arrangement.

Technical Details

• Factory component description: water drain hose.
• Porsche 911 1984–86 /LL installations include 520 mm and 600 mm applications.
• Porsche 911 1987–89 installations include a 600 mm application and a 480 mm /RL application.
• Match the applicable length and routing to the original installation; these application lengths do not describe multiple hoses supplied together.

Product Summary

• Product: Water drain hose.
• Brand: Porsche.
• Part reference: 91157122400.
• Purpose: Carries collected water away from the fresh-air inlet box.
• Selection checks: Model year, installation position, drive-side qualification and applicable hose length.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91157122400

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