UD TRUCKS NISSAN DIESEL BIG THUMB CW520 CW530 CW540 CD520 CK520 RF8 RG8 17.0L 17.9L V8 DIESEL 4PK MULTI-RIB PULLEY ENGINE COOLING WATER PUMP ASSY (OE: 21010-97573-1 / 21010-97573 / 2101097573 / 21010-97573A / 21010-97361 / 2101097361 / 21010-97326 / 21010-97572)

Overview

The UD Trucks / Nissan Diesel Big Thumb CW520 / CW530 RG8 / RF8 4PK Pulley Engine Water Pump Assembly (Water Pump Assy 21010-97573-1 / 21010-97573 / 21010-97573A / 21010-97361 / 21010-97326) is a commercial-grade engine cooling system component engineered specifically for UD Trucks and Nissan Diesel heavy commercial transport trucks, prime movers, and multi-axle tippers powered by Nissan Diesel RG8 (17.9L) and RF8 (17.0L) naturally aspirated and turbocharged V8 direct-injection diesel engines (UD Big Thumb CW520, CW530, CW540, CD520, CK520, CWB520, and C-Series heavy prime movers, logging trucks, cargo lorries, dump trucks, and concrete mixers). Built with an integrated 4PK (4-rib / multi-groove poly-V) serpentine drive pulley, heavy-duty cast iron volute housing, precision-machined multi-bolt perimeter mounting base, and high-flow internal cast impeller, this water pump delivers continuous, pressurized coolant circulation through both cylinder banks, cylinder heads, and engine oil coolers of the massive V8 power plant. Replacing a worn, noisy, bearing-seized, or leaking water pump restores optimal cooling efficiency, preventing engine overheating, cylinder liner cavitation, and blown head gaskets under sustained commercial payloads.

Key Dimensions & Specifications

• Drive & Pulley Configuration: Factory-installed 4PK (4-groove / 4-rib) multi-rib serpentine drive pulley engineered for precise belt tracking, maximum contact friction, and balanced rotation under high engine RPM and torsional loads.

• Heavy-Duty Cast Iron Housing: Thick-walled volute casing with reinforced structural ribs and internal flow runners designed to absorb severe engine vibration, high belt tension, and high thermal stress.

• Mounting Base Configuration: Multi-bolt perimeter mounting flange base with a flat CNC-machined rear sealing surface for direct installation onto the engine timing gear casing / front block water passage cavity.

• Bearing & Mechanical Shaft Seal: Industrial-grade sealed roller/ball bearing cartridge paired with a wear-resistant silicon-carbide/carbon mechanical shaft seal to withstand continuous 4PK belt radial loads and eliminate coolant weepage.

• Coolant Flow Impeller: Dynamically balanced high-efficiency cast internal impeller designed for continuous, high-volume coolant displacement across both cylinder banks of the 17.0L–17.9L V8 engine block.

• Please verify your existing water pump pulley belt profile (4PK multi-rib vs. traditional V-belt), mounting bolt layout, and coolant port orientation against your old sample pump before ordering.

Compatible Truck Models & Engine Applications

• UD TRUCKS / NISSAN DIESEL COMMERCIAL TRUCKS & PRIME MOVERS:

  • Big Thumb Heavy Truck Series (CW520, CW530, CW540, CD520, CK520, CV520, CWB520, CG520 Heavy Prime Movers, Heavy Cargo Lorries, Multi-Axle Tippers, Dump Trucks & Concrete Mixers)

  • Resona & C-Series Heavy Commercial Vehicles running RG8 / RF8 engines

• Engine Application:

  • Nissan Diesel / UD RG8 (17.9L / 17,990cc V8 Naturally Aspirated Direct Injection Diesel)

  • Nissan Diesel / UD RF8 (17.0L / 16,991cc V8 Naturally Aspirated Direct Injection Diesel)

  • Nissan Diesel / UD RH8 (Select compatible 4PK variants)

• OEM & Cross-Reference Part Numbers:

  • 21010-97573-1 / 21010-97573 / 2101097573 (Nissan Diesel / UD Genuine OEM)

  • 21010-97573A / 21010-97573-A

  • 21010-97361 / 2101097361

  • 21010-97326 / 2101097326

  • 21010-97572 / 2101097572

• (Note: Nissan Diesel Big Thumb V8 engines use different belt drive systems across generations: early CW520 models commonly use a traditional V-belt pulley [21010-97402 / A-2150], whereas this 21010-97573-1 / 21010-97573A unit features a 4PK multi-rib serpentine belt pulley for CW530 / CW520 RG8 and RF8 engines. Always confirm your drive belt type [4PK multi-rib] and compare against your old sample pump prior to ordering.)

Why Choose Our Commercial Truck Parts?

• Integrated 4PK Serpentine Belt Pulley: Factory-assembled and dynamically balanced 4PK pulley ensures concentric alignment with the serpentine drive system, eliminating belt slip, vibration, and premature belt wear.

• High-Volume Dual-Bank Coolant Flow: Precision-cast internal impeller delivers steady, pressurized circulation across both cylinder banks and dual oil coolers, eliminating localized hot spots under heavy hauling.

• Heavy-Duty Bearing & Mechanical Seal: High-capacity sealed bearing cartridge paired with a premium silicon-carbide mechanical seal withstands continuous belt tension and high cooling system pressures without developing shaft play or weeping.

• Rigid Cast Iron Volute Body: Thick-walled iron casting resists thermal fatigue, engine vibration, and cracking during heavy commercial operation.

• Precision CNC-Machined Mounting Flange: Flat-machined sealing surface ensures direct bolt-on installation with dependable, leak-free gasket sealing against the engine block.

• Ready Stock & Fast Shipping: Readily stocked for quick dispatch.

Need Help Confirming Fitment?

Unsure whether this 4PK water pump matches your UD Big Thumb truck's existing RG8 or RF8 engine setup?

• Check your old pump against the 4PK multi-rib pulley grooves, mounting base pattern, and port layout.

• Or send your Chassis Number (VIN) / Engine Model (RG8 / RF8) / Pulley Belt Type (4PK) / sample photos to our team via WhatsApp for instant confirmation!