ISUZU 4HK1 4HF1 Gear-Type Positive Displacement Oil Pump Assembly with Integrated Pressure Relief Valve and High-Strength Cast Iron Construction

Oil Pump Assembly with OEM numbers 8-98017585-1 and 8980175851 is a verified direct-fit replacement for ISUZU NPR/NQR/NRR light and medium-duty trucks equipped with 4HK1/4HF1/4HE1/4HG1 diesel engines. This critical engine lubrication component draws oil from the oil pan and delivers pressurized oil to all moving engine components, ensuring proper lubrication and extending engine service life.

This gear-type positive displacement pump is driven by the engine's timing gear train. It draws engine oil from the oil pan through a pickup screen, pressurizes it, and delivers it through the oil filter to the main oil gallery for distribution to critical lubrication points including crankshaft bearings, camshaft bearings, and turbocharger. The integrated pressure relief valve regulates oil pressure by bypassing excess oil back to the sump when pressure exceeds preset thresholds.

• Low oil pressure warning light illumination
• Engine knocking or abnormal noise from bottom end
• Oil pressure drops at idle when engine is hot
• Metal debris in the oil pan
• Oil leakage at pump mounting surface
• Turbocharger failure due to inadequate oil supply

• Always inspect and clean oil pickup screen and oil pan before installation
• Never reuse old oil pump gaskets
• Apply clean engine oil to pump gears before installation
• Tighten oil pump fixing bolts to 25 N·m (18 lb ft)
• Verify oil pressure with mechanical gauge after installation

Each pump undergoes comprehensive quality control including dimensional inspection with CMM, pressure testing, flow rate verification, material hardness testing, and visual inspection to ensure no cracks, porosity, or burrs.

• Standard packaging: Anti-rust oil + VCI film + neutral carton
• Custom packaging options available
• Minimum order quantity: 2 pieces
• Stable batch supply with quality reports