# 21100407 Spring | Genuine Volvo Penta Part

## 🔧 Product Description

A genuine Volvo Penta calibrated compression spring for the oil-pressure control valve inside the TAD650VE/TAD660VE oil cooler and oil-filter housing. The spring applies the specified closing force to control plunger 20862028. Its free length and spring rate determine the pressure at which the internal oil-control circuit begins to open or bypass.

## 🚤 Compatibility

Typically suits:

-   Volvo Penta TAD650VE
-   Volvo Penta TAD660VE

-   **Engine Family:** TAD

## ⚙️ Key Features

-   Calibrated spring rate for the lubricating-oil control valve
-   Works directly with plunger 20862028 and valve seat 21100405
-   Heat-treated spring material maintains force through repeated cycling
-   Correct free length is essential for the designed oil-control threshold
-   Must not be substituted with a similar-size general-purpose spring
-   Engine type: Inline-six industrial diesel lubricating-oil system

## 🔌 Function

Loads the oil-control plunger against its seat and establishes the pressure response of the internal bypass or regulating circuit.

## ⚠️ Common Signs of Failure

-   Low hot-idle oil pressure from a weakened spring
-   Excessively high differential pressure from a seized or incorrect spring
-   Broken or permanently shortened coils
-   Intermittent oil-pressure warnings
-   Abnormal filter bypass or cooler-flow operation

## 🛠️ Service Notes

-   Compare the new spring with the old for free length, wire diameter and number of coils before fitting; springs that look alike often have different rates
-   Never stretch, shim or cut a spring to change its behaviour, and never refit one that has taken a set, is pitted, or shows a bright rubbed patch from coil clash
-   Where springs work as a set, renew the whole set together so the loading stays even
-   Fit the spring the way it came out where the ends or the coil pitch differ from one end to the other, and make sure it seats fully in its locating step or pocket
-   Keep the spring and its seat clean and check for corrosion — a corroded spring in a fuel or engine assembly is a broken spring waiting to happen

## 🔄 Supersession & Cross Reference

### OEM / Related Numbers

-   21100405 - valve seat
-   20862028 - control plunger
-   21100410 - guide/control sleeve
-   21099784 - oil cooler/filter housing

### Other-Brand OEM Numbers

-   VOE21100407

## 📦 Condition

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

## Details

- **Price:** 25.82 AUD
- **Vendor:** Volvo Penta
- **Type:** Oil & Lubrication
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 25.82 AUD | In stock |

## Images

- 21100407 Spring | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21100407-spring-genuine-volvo-penta)
> Updated: 2026-10-08