Product Overview

The Nilfisk NA5 Piston Oil Seal Kit (Part No. 107144102) is a genuine Nilfisk replacement kit designed for MH 4 and MH 5 Series hot water pressure washers. This kit contains high-quality oil seals that prevent water from leaking into the crankcase and contaminating the pump oil.

If you notice that the oil in your pressure washer pump has turned a milky colour, it’s a clear sign that water has entered the oil reservoir — often due to worn or damaged oil seals. Replacing these seals promptly helps to prevent serious internal damage to your pump.

Key Features

✅ Genuine Nilfisk Replacement Kit – Ensures compatibility, reliability, and long service life.
✅ Prevents Water-Oil Contamination – Protects the pump crankcase from emulsified (milky) oil.
✅ Durable Seal Material – Built to handle high pressures and hot water operation.
✅ Easy Maintenance Solution – Designed for straightforward replacement during servicing.
✅ Compatible with Multiple Nilfisk Models – Perfect fit for MH 4 and MH 5 series hot water washers.

Compatible Models

• Nilfisk MH 4 Series

• Nilfisk MH 5 Series

(Compatible with pumps fitted to these series that use the NA5 pump head.)

Technical & Maintenance Advice

If you observe milky oil in the pump’s oil sight glass or reservoir, it indicates that water has leaked past the oil seals. At this stage:

1. Remove the pump head.

2. Inspect the pistons for cracks or scoring.

3. Replace all oil seals using this genuine Nilfisk kit (107144102).

4. Refill with the correct Nilfisk pump oil before reassembly.

Regular inspection and timely replacement will extend pump life and maintain optimal performance.

Why Choose Flowjet?

• Stock genuine Nilfisk service parts and seal kits

• Expert advice from industrial pressure washer specialists

• Fast delivery from our UK-based warehouse in Kendal

• Trade and bulk pricing available on request