# 955999 O-Ring | Genuine Volvo Penta Part

## 🔧 Product Description

Genuine Volvo Penta o-ring included in the repair kit for the operating cylinder and available separately under this number, weighing 0.011 kg and listed for 21 applications across the DPH, DPI, DPR and D ranges.

## 🚤 Compatibility

-   **Engine Family:** DPH, D, DPI, DPR
-   **HP Range:** 150-440 HP

Full model list at the end of this description.

## ⚙️ Key Features

-   Included in the operating cylinder repair kit
-   0.011 kg
-   For DPH, DPI, DPR and D applications
-   Available as a single ring

## 📋 Kit Contents

-   Included in repair kit for operating cylinder.

## 🔌 Function

Seals the operating cylinder joint, squeezed into its groove to hold hydraulic pressure.

## ⚠️ Common Signs of Failure

-   Fluid weeping or dripping at the operating cylinder
-   Steering or shift action going heavy, slow or spongy
-   Ring flattened, hardened or gone shiny
-   Nicks or splits from being pinched on assembly
-   Reservoir level falling with no visible external leak

## 🛠️ Service Notes

-   An operating cylinder that has lost fluid should be stripped and checked properly rather than topped up - the repair kit carries the rest of the seals
-   O-ring 955975 is the equivalent ring listed for the operating cylinder on the older engine ranges

## 🔄 Supersession & Cross Reference

### Aftermarket / Verified Equivalents

-   SLP: OR-999

## 📦 Condition

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

## 🔎 Full Model Compatibility

Typically suits:

-   Volvo Penta D6-330A-F, D6-370A-F, D6-300A-F, D6-300A-G, D6-340A-G, D6-380A-G, D6-400A-G, D6-440A-G, D6-400A-F
-   Volvo Penta D4-260A-F, D4-300A-F, D4-225A-F, D4-150A-G, D4-230A-G, D4-270A-G, D4-320A-G, D4-300A-G
-   Volvo Penta DPH-D1, DPH-E
-   Volvo Penta DPI-A
-   Volvo Penta DPR-D

## Details

- **Price:** 3.71 AUD
- **Vendor:** Volvo Penta
- **Type:** Gaskets & Seals
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 3.71 AUD | In stock |

## Images

- 955999 O-Ring | Genuine Volvo Penta Part
- 955999 O-Ring | Genuine Volvo Penta Part - photo 2 of 2

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/955999-o-ring-genuine-volvo-penta)
> Updated: 2026-09-19