Model: WP12 / WD618
Part Number: 612630060554
Brands: Weichai Power
Engine Model: WP12, WD12, WD618, WP12.430, WP12.460
Engine Type: Diesel
Scope of application: heavy trucks, mining dump trucks, construction machinery, marine and generator engines
The WP12 and WD618 have carried a long list of coolant pump numbers, and 612630060554 is one of the last in that series. The pumps differ mainly in pulley diameter and inlet angle, which are the features that decide whether the belt lines up and whether the hose reaches without strain.
When only the part number is available and the old pump has no readable marking, measure the pulley diameter and the distance from the mounting face to the pulley centreline. Those two figures identify the variant faster than any catalogue and can be taken on the bench with a ruler.
A coolant pump is a volume device, not a pressure device. It moves a certain number of litres per minute at a given speed, and the system's resistance decides the resulting pressure. That is why a worn pump shows up as reduced flow and a temperature rise under load rather than as a pressure gauge reading.
It is also why a partially blocked radiator produces the same symptom as a worn pump. Both reduce flow, and both raise the temperature only when the engine is working hard enough to need the full capacity of the system.
The pump uses a cast iron housing, a cast impeller and a sealed bearing cartridge lubricated for life. The mechanical face seal is tested above operating pressure, and flow is measured at rated speed against the original curve.
The weep hole under the housing is a deliberate design feature: it lets a failing seal drip where it can be seen rather than contaminating the bearing. A small drip is a warning, not something to ignore until the bearing fails.
Fit the pump to a clean surface with a new gasket, torque evenly and bleed the system completely. Trapped air creates local hot spots and can leave a new seal running dry for the first seconds after start-up.
Check the belt path with a straight edge across the pulleys before fitting the pump, and replace any tensioner or idler that shows play. A side-loaded bearing fails quickly, and the failure is usually attributed to the pump rather than to the alignment.
Use the specified coolant mixture and replace it at the recommended interval. Scale and contamination attack the seal faces, and plain water offers no protection at all. In dusty operations, clean the radiator core regularly as well.
Match the engine plate, the old pump number and the pulley dimensions. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping, which is cheaper than returning a pump that does not fit.
Pumps are compact and store well. Two on the shelf with gaskets and thermostat housing seals will cover most of a fleet's needs and avoid a long wait for a part that costs relatively little.
A cooling system is a chain, and the pump is one link. A radiator with a blocked core, a thermostat that opens late or a fan that no longer locks up all produce the same overheating pattern. Replacing the pump without checking those parts is the most common wasted repair on these engines.
Keep the old pump after replacement and look at the seal and bearing. If they are intact, the fault was elsewhere, and knowing that prevents the same mistake next season.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop.
The pump comes with the hub.
Remove the belt and spin the pump by hand.
Browse the Weichai pump category, and pair the pump with the WP12 water pump 612600061945 or the WP12 cylinder liner 612630010055.
Weichai WP12 Water Pump (612630060554). The coolant pump circulates flow through the block and head. Its impeller, seal and bearing are matched to the housing, and the pulley mounting sets belt alignment.
Measure pulley diameter and the distance from the mounting face to the pulley centreline. A correct body casting with the wrong pulley destroys belt alignment within hours.
Numbers beginning 6126 belong to the generation shared with the WD618 and early WP12 engines. Parts in this block were revised several times, so the casting or housing is the reliable identifier rather than the number alone. On this engine, confirm the WP12 application against the engine plate before ordering.
Drain and refill with the correct coolant mix and bleed the system completely. Air in the system causes hot spots and accelerates cavitation damage on the liners.
Ordering note. Payment terms and shipping method are confirmed in writing before dispatch, including the port of loading and the estimated transit time.
Related reading: Cylinder Liner Cavitation: Causes, Symptoms and Prevention
| We Are 30 Years Diesel Engine Parts Supplier | |
| Brand | EPID |
| Warranty | 12 Months |
| Condition | 100%New |
| More Models | Weichai: WP12, WD12, WD618, WP12.430, WP12.460, and other Weichai series. |
| Shipping | By sea / air / express (DHL, FEDEX, TNT, UPS, EMS) |
| Packing | Standard exporting packing or as required |
| Payment Term | L/C, T/T, Western Union, Trade Assurance |
| Delivery Time | 3-7 days (depend on order) |
| Selling Point | 1. On-time Delivery 2. Genuine Quality Assurance 3. Professional Supplier |
The pump uses a cast iron housing, a cast impeller and a sealed bearing cartridge lubricated for life. The mechanical face seal is tested above operating pressure, and flow is measured at rated speed against the original curve.
The weep hole under the housing is a deliberate design feature: it lets a failing seal drip where it can be seen rather than contaminating the bearing. A small drip is a warning, not something to ignore until the bearing fails.
Fit the pump to a clean surface with a new gasket, torque evenly and bleed the system completely. Trapped air creates local hot spots and can leave a new seal running dry for the first seconds after start-up.
Check the belt path with a straight edge across the pulleys before fitting the pump, and replace any tensioner or idler that shows play. A side-loaded bearing fails quickly, and the failure is usually attributed to the pump rather than to the alignment.
Use the specified coolant mixture and replace it at the recommended interval. Scale and contamination attack the seal faces, and plain water offers no protection at all. In dusty operations, clean the radiator core regularly as well.
Match the engine plate, the old pump number and the pulley dimensions. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping, which is cheaper than returning a pump that does not fit.
Pumps are compact and store well. Two on the shelf with gaskets and thermostat housing seals will cover most of a fleet's needs and avoid a long wait for a part that costs relatively little.
A cooling system is a chain, and the pump is one link. A radiator with a blocked core, a thermostat that opens late or a fan that no longer locks up all produce the same overheating pattern. Replacing the pump without checking those parts is the most common wasted repair on these engines.
Keep the old pump after replacement and look at the seal and bearing. If they are intact, the fault was elsewhere, and knowing that prevents the same mistake next season.
Browse the Weichai pump category, and pair the pump with the WP12 water pump 612600061945 or the WP12 cylinder liner 612630010055.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop.
The pump comes with the hub.
Remove the belt and spin the pump by hand.
EPID supplies diesel engine parts for Weichai, Baudouin, Yuchai, Caterpillar, Sinotruk, FAW Xichai and Cummins engines. Every order is checked against the original part number before packing, and our team can identify a part from a photo of the engine plate. Ask for a quotation with your model and quantity and we will reply within one working day.
