# 20405721 Cap Plug | Genuine Volvo Penta Part

## 🔧 Product Description

Genuine Volvo Penta A45 press-fit cap plug used to close cylinder-block core openings. Six are used on four-cylinder blocks and ten on six-cylinder blocks.

## 🚤 Compatibility

-   **Engine Family:** D, TD, TAD, MD

Full model list at the end of this description.

## ⚙️ Key Features

-   A45 press-fit cylinder-block core plug
-   Six used on D5 four-cylinder blocks and ten on D7 six-cylinder blocks
-   Closes casting-core openings in the coolant jacket or block
-   Requires correct bore preparation and installation depth
-   Should be replaced if removed or corroded
-   Engine type: Volvo Penta 5- and 7-litre industrial diesel

## 🔌 Function

Closes the cylinder-block casting-core openings and retains coolant or internal gallery integrity.

## ⚠️ Common Signs of Failure

-   Coolant leakage from a core plug
-   Plug corrosion or perforation
-   Plug displaced by freezing or pressure
-   Damaged block bore
-   Slow coolant loss

## 🛠️ Service Notes

-   Fit a new plug rather than refitting a used one — a plug that has been driven or screwed out will not seal reliably a second time
-   Clean the bore or threads out fully and check the sealing seat for corrosion pitting and damage; a pitted seat will keep weeping whatever plug is fitted
-   Fit the plug squarely and to the depth or tightness given in the workshop manual for your engine, using only the sealant or thread compound specified for that joint
-   Support the surrounding casting where you can and drive or tighten without distorting the plug, then pressure test or run the engine up and check the plug for weeping

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   20405721 → Supersedes 20405720 → Supersedes 11700286

### OEM / Related Numbers

-   20405720 earlier number superseded by this part
-   11700286 earlier number superseded by this part
-   20405719 - M22 block plug
-   20405717 - M30 plug
-   11700284 - related block bushings
-   11700285 - related block bushings

## 📦 Condition

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

## 🔎 Full Model Compatibility

Typically suits:

-   Volvo Penta D7A-B TA, D7A-T, D7A-TA, D7C-B TA, D7C-TA
-   Volvo Penta D5A-B TA, D5A-T, D5A-TA
-   Volvo Penta MD2010, MD2010B
-   Volvo Penta TAD520GE, TAD520VE
-   Volvo Penta TAD530GE MECH, TAD530GE EDC4
-   Volvo Penta TAD531GE MECH, TAD531GE EDC4
-   Volvo Penta TAD720GE, TAD720VE
-   Volvo Penta TAD721GE, TAD721VE
-   Volvo Penta TAD722GE, TAD722VE
-   Volvo Penta TAD730GE MECH, TAD730GE EDC4
-   Volvo Penta TAD731GE MECH, TAD731GE EDC4
-   Volvo Penta TAD750GE, TAD750VE
-   Volvo Penta TD520GE, TD520VE
-   Volvo Penta TD720GE, TD720VE PP
-   Volvo Penta TAD420VE
-   Volvo Penta TAD532GE EDC4
-   Volvo Penta TAD550GE
-   Volvo Penta TAD551GE
-   Volvo Penta TAD560VE
-   Volvo Penta TAD561VE
-   Volvo Penta TAD620VE
-   Volvo Penta TAD650VE
-   Volvo Penta TAD660VE
-   Volvo Penta TAD732GE EDC4
-   Volvo Penta TAD733GE EDC4
-   Volvo Penta TAD734GE
-   Volvo Penta TAD751GE
-   Volvo Penta TAD752GE
-   Volvo Penta TAD753GE
-   Volvo Penta TAD754GE
-   Volvo Penta TAD760VE
-   Volvo Penta TAD761VE
-   Volvo Penta TAD762VE
-   Volvo Penta TAD763VE
-   Volvo Penta TAD764VE
-   Volvo Penta TAD765VE
-   Volvo Penta TD420VE

## Details

- **Price:** 14.78 AUD
- **Vendor:** Volvo Penta
- **Type:** Fasteners & Fixings
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 14.78 AUD | In stock |

## Images

- 20405721 Cap Plug | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/20405721-cap-plug-genuine-volvo-penta)
> Updated: 2026-10-09