# 20405829 Cap | Genuine Volvo Penta Part

## 🔧 Product Description

Genuine Volvo Penta service cap fitted to air cleaner 20405837 on the TD720GE Stage 1 / Tier 1 engine. It closes the housing around filter insert 3840034.

## 🚤 Compatibility

Typically suits:

-   Volvo Penta TD720GE
-   Volvo Penta TD520VE
-   Volvo Penta TAD720GE
-   Volvo Penta TAD520VE

-   **Engine Family:** TD, TAD

## ⚙️ Key Features

-   Air-cleaner housing end cap
-   Confirmed specifically for TD720GE
-   Used with filter insert 3840034
-   Works with dust ejector 20405839
-   Must seal and latch securely
-   Engine type: Volvo Penta 7-litre industrial diesel

## 🔌 Function

Closes the air-cleaner housing and retains the filter insert against its sealing surface.

## ⚠️ Common Signs of Failure

-   Dust entry around the cap
-   Broken or loose latch
-   Cracked or distorted cap
-   Filter element movement
-   Poor sealing to the cleaner body

## 🛠️ Service Notes

-   Clean and inspect the seating face on the housing as well as the cap — most leaks past a cap are the seat or the seal rather than the cap body
-   Renew any separate O-ring or gasket that goes with the cap, and lubricate rubber seals lightly with clean oil or grease so they slide home instead of rolling or tearing
-   Do not over-tighten a cap into a plastic or aluminium housing; it seals on its gasket or O-ring, not on force, and stripped threads mean a much bigger repair
-   Where a cap blanks a port during a repair, keep it fitted right up to the moment of assembly so nothing enters the opening
-   Check the cap is fully home and that any retaining clip, lanyard or locking tab is secure before returning the boat to service

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   20405829 → Supersedes 21056447

### OEM / Related Numbers

-   21056447 earlier number superseded by this part
-   20405837 - complete air cleaner
-   3840034 - filter insert, related earlier number 20405830
-   20405839 - dust ejector
-   20405833 - mounting bracket

## 📦 Condition

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

## Details

- **Price:** 216.65 AUD
- **Vendor:** Volvo Penta
- **Type:** Inlet & Exhaust
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 216.65 AUD | In stock |

## Images

- 20405829 Cap | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/20405829-cap-genuine-volvo-penta)
> Updated: 2026-09-19