# 22857175 Mercury MerCruiser Coupling | Genuine Quicksilver OEM Part

🔧 Product Description

  

Genuine Quicksilver Coupling Insert - Part Number: 22-857175

  

Genuine Quicksilver/Mercury coupling insert used with the Mercury coastal flush system. This OEM coupling adapts a fresh-water hose connection to the engine flush port, allowing the cooling passages to be flushed after saltwater use and helping reduce salt, sand and debris build-up inside the cooling system.

  

⚙️ Key Features

  

• Genuine Quicksilver/Mercury OEM coupling insert

• Used as a fresh-water flush adapter for compatible Mercury coastal flush systems

• Commonly used with Mercury outboard coastal flush kit assemblies

• Helps connect a garden hose or flush line to the engine flush port

• Direct replacement for earlier Mercury flush coupling references

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 22-857175 → Supersedes 22-861405

• 22-861405 (earlier OEM reference)

  

OEM / Related Numbers:

  

• 22-857175

• 857175

• 22857175

• 22-861405

• 861405

• 22-857176 coupling body, related component

• 857176 coupling body, related component

• 858566A02 coastal flush kit, related assembly

• 858566A03 coastal flush kit, related assembly

  

Aftermarket / Verified Equivalents:

  

• No aftermarket equivalent

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury outboard coastal flush kit assemblies

• Mercury and Mariner outboards with front coastal flush port connection

• Selected MerCruiser and inboard/towsports flush adapter systems where 857175 is listed

  

Typically suits:

  

• Engine models:

• Mercury Optimax 75HP Saltwater outboards, 2004 onwards, where fitted with coastal flush kit

• Mercury Optimax 90HP Saltwater outboards, 2004 onwards, where fitted with coastal flush kit

• Mercury Optimax 115HP Saltwater outboards, 2004 onwards, where fitted with coastal flush kit

• Mercury 75HP EFI 4-Stroke, serial range 1B366823 - 2B094995, coastal flush kit outboard assembly

• Mercury 80HP EFI 4-Stroke, serial range 1B366823 and up, coastal flush kit outboard assembly

• Mercury 80HP EFI 4-Stroke, serial range 0P459572 - 2B094995, Belgium-built applications with coastal flush kit

• Mercury 100HP EFI 4-Stroke, serial range 0P459572 - 2B094995, Belgium-built applications with coastal flush kit

• Mercury 115HP EFI 4-Stroke, serial range 1B366823 - 2B094995, coastal flush kit outboard assembly

• Mercury 115 Pro XS Optimax 1.5L applications using coastal flush kit 858566A02

• Mercury / Mariner Optimax 75HP and above saltwater-model outboards using the front coastal flush port

• MerCruiser 350 MAG MPI MIE, serial range 0M398372 - 0W389999, standard cooling system flush fitting application where listed

• MerCruiser 5.7L MPI MIE EC, serial 1A092169 and up, closed-cooling sea water pump hose / flush fitting application where listed

  

• HP Range: Approximately 75HP and above for Mercury Optimax saltwater outboard coastal flush applications; MerCruiser fitment depends on engine package

• Engine Type: Mercury / Mariner outboard coastal flush system and selected MerCruiser flush adapter systems

• Year Range: Approximately 2004 onwards for Optimax saltwater coastal flush applications, with additional model-specific MerCruiser and 4-stroke applications by serial number

  

🔌 Function

  

The coupling insert connects the fresh-water flush hose to the engine flush port so the cooling system can be flushed after operation. Regular flushing helps remove salt, minerals, sand and other contaminants from the cooling passages, helping protect the cooling system and extend service life.

  

Common signs of failure:

  

• Missing or damaged flush coupling

• Fresh-water hose will not connect securely to the flush port

• Water leaking around the flush adapter connection

• Cross-threaded or worn coupling connection

• Flush system cannot be used after saltwater operation

• Incorrect adapter causing poor sealing or water spray during flushing

  

📦 Condition

  

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 84.4 AUD
- **Vendor:** Quicksilver
- **Tags:** Quicksilver Marine Parts | Oils Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 84.40 AUD | In stock |

## Images

- 22857175 Mercury MerCruiser Coupling | Genuine Quicksilver OEM Part
- 22857175 Mercury MerCruiser Coupling | Genuine Quicksilver OEM Part
- 22857175 Mercury MerCruiser Coupling | Genuine Quicksilver OEM Part
- 22857175 Mercury MerCruiser Coupling | Genuine Quicksilver OEM Part

---

> Source: [Sawley's Auto and Marine](www.sawleysautoandmarine.com.au/products/22857175-mercury-mercruiser-coupling-genuine-quicksilver-oem-part)
> Updated: 2026-05-17