495B-31000A Engine Oil Pump for XinChai 495 Forklift Diesel Engine

The 495B-31000A is an OEM-spec engine oil pump designed for the XinChai 495, A495BPG, and 495B 4-cylinder diesel engines powering 2-4 ton HELI, Hangcha, and Lonking internal combustion counterbalance forklifts. This 12-cog gear-type oil pump is the heart of the engine’s lubrication system, drawing oil from the sump through the pickup screen and delivering pressurized oil — typically 2-5 bar at operating temperature and RPM — to the main bearings, connecting rod bearings, camshaft journals, valve rocker assembly, turbocharger (if equipped), piston cooling jets, and timing gear train. The pump’s 12-tooth gear rotor design provides positive-displacement oil delivery with flow rates proportional to engine RPM, ensuring adequate lubrication pressure at hot idle (minimum 1.0 bar) while delivering full flow at rated speed. A worn oil pump — characterized by excessive internal gear-to-housing clearance, scored rotor surfaces, or a stuck pressure relief valve — produces the classic symptoms of low oil pressure at idle, a flickering or illuminated oil pressure warning light, increased engine noise from bearing wear, and ultimately main or connecting rod bearing failure if not addressed promptly.

The pump body and cover are manufactured from high-grade cast iron with precision-machined internal cavities that house the 12-cog drive gear and driven gear rotor set. The gears are manufactured from sintered powder metal or machined alloy steel, with gear tooth profiles optimized for smooth, low-pulsation oil delivery and quiet operation. The critical internal clearances — gear tip-to-housing, gear end-to-cover, and gear-to-gear mesh — are maintained to tolerances of 0.05-0.15mm to maximize volumetric efficiency while preventing metal-to-metal contact during thermal expansion. An integrated pressure relief valve, consisting of a spring-loaded steel plunger in a honed bore, opens at approximately 5-6 bar to bypass excess oil directly back to the sump, preventing over-pressurization that could rupture the oil filter or blow out gaskets during cold starts when oil viscosity is highest. The pump is driven via the crankshaft timing gear or an intermediate idler gear, with the 12-cog drive gear meshing directly with the engine’s timing gear train for positive, slip-free drive.

Direct OEM replacement for XinChai 495, A495BPG, 495B, and compatible 4-cylinder diesel engines using the 495B-31000A oil pump. Fits HELI CPCD20-CPCD40, Hangcha CPCD20-CPCD40, Lonking LG20DT-LG40DT, and equivalent 2-4 ton forklifts. When replacing the oil pump, always install a new oil pump gasket or apply the specified liquid gasket compound to the mounting flange. Prime the pump by packing the gear cavity with clean engine assembly lubricant or petroleum jelly before installation — this ensures the pump draws oil immediately on first start rather than running dry. Replace the oil pickup screen if it shows signs of sludge accumulation or mesh damage. After installation, crank the engine with the fuel shut-off engaged until the oil pressure gauge registers pressure, then start and verify 2-5 bar pressure at 2000 RPM with the engine at operating temperature. For compatible oil filters, engine oil (15W-40 diesel grade), oil pressure sensors, timing gears, and complete engine gasket kits, visit our Forklift Engine Parts section. For XinChai 495 lubrication system specifications, refer to XinChai Power technical documentation.

Technical Specifications

• PN: 495B-31000A
• Engine: XinChai 495 / A495BPG / 495B Compatible
• Type: 12-Cog Gear-Type Positive Displacement Oil Pump
• Body Material: Cast Iron with Precision-Machined Cavities
• Gears: 12-Tooth Rotor Set, Sintered or Alloy Steel
• Pressure: 2-5 bar Operating; Relief Valve Opens 5-6 bar
• Drive: Crankshaft Timing Gear via 12-Cog Gear Mesh
• Includes: Integrated Pressure Relief Valve

Compatible Forklift Models

Each 495B-31000A oil pump undergoes comprehensive QC: gear tip-to-housing clearance measurement, gear end-float verification, pressure relief valve crack pressure testing, and flow rate verification on a calibrated test stand using heated oil at 80°C to simulate operating conditions. The pump ships with the mounting flange protected, the gear cavity pre-filled with assembly preservative, and packed in a VCI anti-corrosion bag inside a foam-lined box. 12-month warranty. Critical installation note: never use a gasket thicker than OEM specification on the oil pump mounting flange, as this increases gear end-float and reduces pumping efficiency. For engine lubrication system diagnostics, oil pressure troubleshooting, or fleet maintenance programs, contact our technical team.