Isuzu Diesel Oil Pump 8-94114-491-1 — 4BC2, 4BE1, 4BD1, NPR59 Engines, 4-Cylinder, 1.2kg, TOPS Brand
This is the diesel engine oil pump (part number 8-94114-491-1) for Isuzu 4BC2, 4BE1, 4BD1, and NPR59 4-cylinder diesel engines — the engine-driven pump that circulates pressurized engine oil through the crankshaft main bearings, connecting rod bearings, camshaft bearings, piston cooling jets, valve train, and turbocharger bearings. The oil pump is the heart of the engine lubrication system — it draws oil from the oil pan through a pickup screen and delivers it at 30-60 psi (2-4 bar) to every rotating and sliding surface in the engine. The Isuzu 4B-series engine oil pump is typically a gear-type pump driven directly from the crankshaft or camshaft — the pump gears mesh together and trap oil between the gear teeth and the pump housing, carrying it from the inlet port to the outlet port. A failed oil pump — from worn gear teeth (excessive clearance between the gear tips and the pump housing causes internal leakage that reduces output pressure), a stuck pressure relief valve (stuck open causes low pressure; stuck closed causes excessive pressure that blows out the oil filter seal), or a damaged drive mechanism (sheared drive key or stripped drive gear) — causes immediate and catastrophic engine damage because every bearing surface loses its oil film simultaneously. The oil pressure warning light is the most critical warning light on any engine dashboard — if it illuminates while the engine is running, stop the engine immediately. Continuing to run an engine with zero or low oil pressure for even 30 seconds can destroy the crankshaft, connecting rods, camshaft, and turbocharger beyond repair.
TOPS brand, manufactured in Guangdong, China. 1.2 kg weight, 4-cylinder engine application. For Isuzu 4BC2-b, 4BE1, 4BD1, and NPR59 diesel engines in excavators and forklifts. Strong carton packing. MOQ: 1 set. When replacing an oil pump, always replace the oil pump pickup screen/strainer at the same time — a clogged or damaged pickup strainer starves the new pump of oil and causes immediate failure. Prime the oil pump by packing it with assembly lube or petroleum jelly before installation — a dry pump cannot create suction to draw oil from the pan. After installation, crank the engine with the fuel shut off until oil pressure registers on the gauge before starting — this ensures all bearings receive oil before the engine fires. Check oil pressure at hot idle and at rated speed — compare to the Isuzu 4B-series specification. Replace the engine oil and filter after pump replacement to remove any debris from the old pump failure.
Compatible with Isuzu 4BC2, 4BE1, 4BD1, and NPR59 diesel engines in excavators and forklifts. Browse our oil pump selection. Visit Isuzu official website.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 8-94114-491-1 |
| Brand | TOPS |
| Engine Models | 4BC2 / 4BE1 / 4BD1 / NPR59 |
| Cylinders | 4-Cylinder Diesel |
| Weight | 1.2 kg |
| MOQ | 1 Set |
Compatible Engines
| Engine | Application |
|---|---|
| Isuzu 4BC2 / 4BE1 / 4BD1 | Forklift / Excavator Diesel |
Prime with assembly lube. Confirm your engine model →

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