Engine Water Pipe Hose 8-97160257-1 8971602570 For ISUZU NPR NQR NPR-HD 4HE1 4.8L — OEM Upper Radiator Inlet Hose, Verified Direct Fit, EPDM Rubber Coolant Hose

The Engine Water Pipe Hose with OEM numbers 8-97160257-1 / 8971602570 is a verified direct-fit upper radiator inlet hose for ISUZU NPR, NPR-HD, and NQR series trucks equipped with the 4HE1 4.8L diesel engine (1998-2004). This critical engine cooling system component channels coolant from the radiator to the engine to maintain proper operating temperature and prevent overheating.

• Material & Construction: EPDM rubber with knitted rayon reinforced inner base tube for maximum strength and burst resistance
• Temperature Rating: -40°F to +275°F (-40°C to +135°C) in coolant hose applications
• Dimensional Verification: Centerline length 533 mm (21 in), Inside Diameter 1: 34 mm (1.33 in), Inside Diameter 2: 1 7/16 in
• Installation Success Rate: Direct bolt-on fitment with factory clamps and connections
• OEM Cross-Reference Verified: Replaces 8-97160257-1, 8971602570, 8-97160-257-1, 8-97160-257-0, 8971602571, 8973305290, 8-97330529-0, 8-97330-529-0

• Coolant leaks: Visible drips or puddles under the vehicle, low coolant levels requiring frequent top-ups
• Engine overheating: Temperature gauge rising above normal operating range
• Cracked, spongy, or hardened hose: Visual inspection reveals degradation, swelling, or stiffness
• Coolant residue or white staining: Dried coolant traces around hose connections
• Loose or brittle hose clamps: Clamps that no longer hold tension

Manufacturing conforms to SAE J20R3, Class D-1 and SAE J1684 Type EC standards for automotive coolant hose applications.

1. Drain coolant: Place a drain pan under the radiator, open the drain cock, and allow coolant to drain completely
2. Remove old hose: Loosen the hose clamps at both ends, twist the hose to break the seal, and remove it
3. Clean mating surfaces: Wipe both connection points clean and inspect for cracks, pitting, or deformation
4. Install new hose: Position the new upper radiator inlet hose onto the radiator outlet and engine inlet
5. Secure clamps: Tighten hose clamps to specification without over-tightening
6. Refill coolant: Refill with manufacturer-recommended coolant mixture and bleed the cooling system
7. Pressure test: Run the engine to operating temperature and check for leaks

• Inspect the upper radiator hose at every 40,000-50,000 km or annually
• Replace immediately if the hose shows signs of cracking, swelling, hardening, or coolant weeping
• Replace coolant according to manufacturer's interval (typically every 2 years or 50,000 km)
• When replacing one hose, consider inspecting the lower radiator hose, bypass hose, and heater hoses

• Standard packing: Plastic bag with neutral packaging; color box or customer-branded packaging available for bulk orders
• Suitable for: Engine rebuild workshops, fleet maintenance departments, spare parts distributors, and export wholesalers
• Related parts available: Complete 4HE1 cooling hose set (inlet + outlet + bypass), radiator cap, thermostat, water pump