The WEICHAI WP12 Oil Cooler Assembly is a critical thermal management component engineered for the WP12 series heavy-duty diesel engines. This assembly ensures optimal oil temperature regulation, preventing lubricant degradation and maintaining viscosity under extreme loads. When you choose genuine WEICHAI Engine Parts, you secure superior cooling efficiency and extended engine life. The WEICHAI WP12 Oil Cooler Assembly features a stacked-plate design with high-turbulence cores, capable of reducing oil temperature by up to 25°C under peak torque conditions. Every unit is pressure-tested to 16 bar and coated against corrosion, making it the ideal replacement for fleet maintenance, construction equipment, and marine propulsion systems.
The WEICHAI WP12 Oil Cooler Assembly is a heat exchanger specifically designed to maintain engine oil within optimal temperature range (85–105°C). It mounts directly onto the engine block or filter housing, using engine coolant to absorb excess heat from the lubricating oil. This prevents oil oxidation, sludge formation, and viscosity breakdown that often leads to premature bearing wear. The assembly consists of a stacked aluminum core, cast housing, and bypass valve to ensure consistent oil flow even during cold starts.
Unlike traditional tube-and-shell coolers, the WP12 oil cooler utilizes brazed plate technology with multiple flow channels, increasing heat transfer surface area by 40% while occupying minimal space. Each cooler is calibrated for the WP12’s oil pump capacity, ensuring a pressure drop of less than 0.8 bar at maximum flow. This precision engineering makes it indispensable for engines operating in high-ambient temperatures, mountainous terrain, or stop-and-go urban driving where thermal stress is severe.
The assembly also integrates a built-in oil thermostat that bypasses the cooler until oil reaches 80°C, accelerating warm-up and reducing friction. Once the threshold is crossed, full flow is directed through the cooling core. This dual-mode operation improves fuel efficiency by 3–5% during cold starts and protects the oil from thermal shock. OEM-grade seals and gaskets are pre-installed, eliminating leak points and simplifying installation for workshop technicians.
Every WEICHAI WP12 Oil Cooler Assembly undergoes a rigorous 100% leak test under 2.0 MPa air pressure and is stamped with a batch code for traceability. The external surfaces are e-coated to resist salt spray and chemical corrosion, making it suitable for off-highway equipment exposed to mud, dust, and de-icing salts. Whether you are replacing a failed cooler or upgrading an existing engine, this assembly guarantees OE form, fit, and function.
Product Parameters of WEICHAI WP12 Oil Cooler Assembly
NO.
Part NO.
Description
1
612630150234
Oil Cooler Core (30-plate, Brazed Aluminum)
2
612630160289
Cast Iron Housing (WP12 Specific)
3
612630170312
Oil Bypass Thermostat (80°C Opening)
4
612630180345
Housing Gasket (Reinforced Fiber)
5
612630190378
O-Ring Seal Kit (Viton, High Temp)
6
612630200401
Mounting Stud Bolt Kit (M10x1.5)
7
612630210423
Oil Inlet/Outlet Adapter (Straight)
8
612630220445
Coolant Connection Elbow (90°)
9
612630230467
Pressure Relief Valve (2.5 bar)
10
612630240489
Complete Assembly (Pre-sealed)
11
612630250502
Drain Plug (Magnetic, M14)
12
612630260514
Identification Tag (Laser Etched)
Why Choose Our WEICHAI WP12 Oil Cooler Assembly?
Our WEICHAI WP12 Oil Cooler Assembly is manufactured under ISO/TS 16949 certified facilities, using only high-grade aluminum and cast iron sourced from approved mills. Each core undergoes a vacuum brazing process that eliminates flux residues and ensures uniform bond strength across all contact points. Independent lab tests confirm that our coolers withstand over 500 thermal shock cycles from -40°C to 125°C without leakage, far exceeding industry standards for heavy-duty applications.
We provide complete interchangeability with original WP12 engine configurations. The bolt pattern, thread sizes, and coolant port positions exactly match factory specifications, eliminating the need for adapters or modifications. Moreover, our assembly includes all necessary gaskets and O-rings pre-installed, reducing installation errors. Many aftermarket coolers omit the bypass thermostat or use inferior seals, leading to premature failure; our unit retains every functional feature of the genuine design.
We back every WEICHAI WP12 Oil Cooler Assembly with a 24-month unlimited-mileage warranty covering material and workmanship defects. Our logistics network ensures that 98% of orders ship within 24 hours, minimizing vehicle downtime. Additionally, we offer batch traceability – each unit’s serial number can be used to access test reports, material certificates, and production date. This transparency is critical for fleet managers who require consistent quality across hundreds of vehicles.
Compared to original equipment dealer pricing, our assembly delivers 30–40% cost savings without compromising on cooling performance. We achieve this through efficient direct sourcing and volume production. Independent dyno tests on a WP12 engine showed that our oil cooler maintains oil temperature within 3°C of the OE unit at full load (2200 rpm, 350 kW). Choosing our assembly means you get premium reliability at a competitive price, backed by a responsive support team.
What are the Routine Maintenance Considerations for the WEICHAI WP12 Oil Cooler Assembly?
Inspect the oil cooler assembly every 50,000 km or 800 operating hours for external leaks, especially around the housing gasket and coolant connections. Use a UV dye in the engine oil to detect micro-cracks that may not be visible under normal light. Any sign of oil in the coolant reservoir or coolant in the oil pan indicates internal core failure and requires immediate replacement. Always replace the mounting gasket and O-rings when reinstalling a cooler.
Flush the cooling system every two years with a low-phosphate cleaner to remove scale and debris that can clog the coolant side of the oil cooler. A blocked cooler reduces heat exchange efficiency and may cause oil temperatures to exceed 125°C, triggering engine derate. When flushing, ensure the oil cooler bypass valve is closed (or removed) to force cleaning solution through the core. Never use high-pressure air or water directly on the core fins as this may damage the brazed joints.
Always use genuine WEICHAI oil filters and API CK-4 or FA-4 grade engine oil. Non-genuine filters may have incorrect bypass valve settings, causing unfiltered oil to enter the cooler and accelerate internal sludge accumulation. During oil changes, remove the cooler drain plug (if equipped) to evacuate old oil completely. Torque the mounting bolts to 45 Nm in a crisscross pattern to avoid distorting the housing. Re-torque after the first heat cycle.
If the engine experiences a major failure (e.g., bearing seizure or piston meltdown), always replace the oil cooler assembly regardless of visible damage. Debris from the failed component can lodge inside the cooler’s narrow passages, restricting oil flow and causing secondary failure. For storage of spare WEICHAI WP12 Oil Cooler Assembly, keep in a dry environment between -20°C and 50°C, with protective caps on all ports. Following these guidelines will maximize the service life of your oil cooling system.
If you have any questions about our products, services, or anything related to what we offer, please don’t hesitate to leave us a message—our dedicated team is always ready to provide prompt and helpful responses to address your concerns. What’s more, when you become our valued customer, we’re delighted to offer you complimentary catalog services, giving you access to detailed, up-to-date information on our full range of products, specifications, and offerings to help you make informed decisions.
