21389074 Rubber Bellows | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta Saildrive Rubber Bellows / Diaphragm Seal Kit - Part Number: 21389074

Primary through-hull rubber diaphragm service kit for compatible Volvo Penta saildrives. The diaphragm forms the flexible watertight barrier between the saildrive leg and the hull opening, while the external cover protects the installation at the hull surface. Volvo Penta service guidance commonly specifies replacement at least every seven years, or earlier if deterioration is found.

⚙️ Key Features

• Genuine Volvo Penta saildrive through-hull sealing kit

• Forms the primary flexible water barrier around the saildrive leg

• Includes the main diaphragm and external hull cover components listed below

• Suitable for established 110S, 120S, 130S, 150S and MS25S saildrive families

• Preventive replacement item commonly renewed on a seven-year service interval

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 21389074 (current Volvo Penta service-kit reference)

• Replaces earlier Volvo Penta references: 21112450, 3840050, 3856597, 877362, 872026, 854934

OEM / Related Numbers:

• 22303438 - external hull cover / rubber flap supplied with the service kit

• 854932 - earlier reference for the external hull cover / rubber flap

• 22222853 - clamping ring used on specified 130S and 150S installations; inspect and order separately when required

Aftermarket / Verified Equivalents:

• RECMAR: REC877362

Kit Contents:

• Main saildrive through-hull rubber diaphragm / bellows: 21389074

• External hull cover / rubber flap: 22303438, superseding 854932

🚤 Compatibility

Commonly used on:

• Volvo Penta saildrive installations requiring the 21389074 through-hull diaphragm service kit

Typically suits:

• Saildrive models:

• 110S

• 120S, 120S-B, 120S-C, 120S-D, 120S-E

• S120C

• 130S, 130SR

• 150S

• MS25S

• SR saildrive applications using the corresponding diaphragm arrangement

• HP Range: Saildrive-model controlled; not selected by engine horsepower alone

• Engine Type: Inboard marine diesel with Volvo Penta saildrive

• Year Range: Saildrive model- and serial-controlled; verify the drive designation before ordering

🔌 Function

Seals the opening where the saildrive passes through the hull while allowing controlled movement between the engine, saildrive and vessel structure. The external cover reduces direct exposure of the diaphragm area to water flow and debris.

Common signs of failure:

• Surface cracking, checking, hardening or loss of elasticity

• Distortion, swelling or separation of the rubber diaphragm

• Water seepage or dampness around the saildrive hull opening

• Corrosion or staining around the clamping ring and retaining surfaces

• Diaphragm age exceeding the recommended service interval

📦 Condition

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging