# 21189037 Expansion Plug | Genuine Volvo Penta Part

## 🔧 Product Description

Genuine expansion plug used in the governor-housing or fuel-control assembly of the Volvo Penta D1-30F marine diesel engine. It closes a machined opening in the housing.

## 🚤 Compatibility

Typically suits:

-   Volvo Penta D2-40F
-   Volvo Penta D1-30F

-   **Engine Family:** D
-   **HP Range:** 30-40 HP

## ⚙️ Key Features

-   Confirmed D1-30F governor-system application
-   Factory diameter and material
-   Closes a machined housing passage
-   Designed for the engine operating environment
-   Requires correct seating depth

## 🔌 Function

The plug seals the machining opening in the governor housing and prevents fluid leakage or contamination entry.

## ⚠️ Common Signs of Failure

-   Seepage around the plug
-   Plug displaced from the bore
-   Damage caused during previous disassembly

## 🛠️ Service Notes

-   Clean the bore out to bare, sound metal and check it for corrosion, pitting or a raised lip — a plug will not seal in a wasted or scored bore, and that bore may need attention first
-   Fit the plug square to the bore and drive it evenly with a tool or socket that bears on the correct part of the plug, to the depth the manual specifies; driven in cocked or too deep it will leak
-   Seal it with a sealant of the type specified for that joint, not with a silicone or rubbery compound, which is slippery and lets a plug creep out under pressure
-   With an expanding rubber type, seat it fully, then tighten the centre nut to expand it against the bore and check it again after the first heat cycle
-   Fill, pressure-test or run the system and check the plug for weeping before closing up access, since many of these sit where you cannot see them once the engine is back together

## 📦 Condition

-   Genuine Volvo Penta part
-   Brand new
-   Supplied in original or equivalent packaging

## Details

- **Price:** 20.87 AUD
- **Vendor:** Volvo Penta
- **Type:** Fasteners & Fixings
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 20.87 AUD | In stock |

## Images

- 21189037 Expansion Plug | Genuine Volvo Penta Part
- 21189037 Expansion Plug | Genuine Volvo Penta Part - photo 2 of 2

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21189037-expansion-plug-genuine-volvo-penta)
> Updated: 2026-09-06