Model: WP12 / WD618
Part Number: 612630061057
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 several coolant pump numbers, and 612630061057 is one of them. The differences are visible when the old pump is placed beside the new one: pulley diameter, pulley offset and inlet angle are the three features that decide whether it will align and seal.
That is why a photograph of the old pump with a ruler alongside is more useful than a description over the phone. Getting the pulley wrong is the most common reason a correct pump fails within hours of fitting, because the belt then runs out of line and side-loads the bearing.
A water pump does not work in isolation. It moves coolant through the block, head, oil cooler and radiator, and its performance depends on the thermostat opening, the radiator being clear and the system holding pressure. A pump that is blamed for overheating is sometimes only revealing a problem elsewhere.
Before replacing a pump for overheating, check the coolant level and condition, confirm the thermostat opens, feel the radiator top and bottom hoses for a temperature difference, and inspect the fan drive. Each of those checks takes minutes and can save an unnecessary part.
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, because that is where most failures begin.
On a heavy truck, the first sign is often a coolant smell at the front of the engine rather than a visible leak. The weep hole drips onto hot metal, the coolant evaporates and leaves a white crust that is easy to miss until it accumulates.
Fit the pump to a clean surface with a new gasket, torque evenly and bleed the system fully. Most repeat failures after a pump replacement come from incomplete bleeding rather than from the part itself.
The mechanical seal is the part that fails first, and coolant quality decides how long it lasts. Scale, incorrect inhibitor concentration and contamination all attack the seal faces. Use the specified coolant mixture and replace it at the recommended interval rather than topping up indefinitely.
Check the belt path with a straight edge across the pulleys before fitting the new pump, and replace any tensioner or idler that shows play. A side-loaded bearing fails quickly, and the failure looks like a pump quality problem when it is really an alignment problem.
Pumps are compact, do not deteriorate in storage and fit several ratings in the family. For a fleet, two on the shelf with gaskets and thermostat housing seals turn a week of downtime into an afternoon repair.
When a manufacturer issues a new pump number for the same engine, the reason is usually a supplier change, a revised seal or a different pulley to suit a new accessory layout. The pumping element itself rarely changes much, which is why two pumps can look identical and still not be interchangeable on the vehicle.
If the old pump has no readable number, compare the pulley diameter and the distance from the mounting face to the pulley centreline. Those two measurements identify the variant faster than any catalogue, and they can be taken with a ruler on the bench.
Compare the pulley diameter and offset, or send us a photo of the old pump.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop.
The pump comes with the hub.
Browse the Weichai pump category, and pair the pump with the WP12 water pump 612630061060 or the WP12 full gasket kit 612600900279.
Weichai WP12 Water Pump (612630061057). 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.
Do not over-tension the belt. Excess tension loads the pump bearing directly and is a common cause of repeat failures.
Ordering note. Every shipment leaves with a packing list matched to the invoice, which matters when a rebuild is waiting on one seal and the whole pallet has to be cleared through customs.
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, because that is where most failures begin.
On a heavy truck, the first sign is often a coolant smell at the front of the engine rather than a visible leak. The weep hole drips onto hot metal, the coolant evaporates and leaves a white crust that is easy to miss until it accumulates.
Fit the pump to a clean surface with a new gasket, torque evenly and bleed the system fully. Most repeat failures after a pump replacement come from incomplete bleeding rather than from the part itself.
The mechanical seal is the part that fails first, and coolant quality decides how long it lasts. Scale, incorrect inhibitor concentration and contamination all attack the seal faces. Use the specified coolant mixture and replace it at the recommended interval rather than topping up indefinitely.
Check the belt path with a straight edge across the pulleys before fitting the new pump, and replace any tensioner or idler that shows play. A side-loaded bearing fails quickly, and the failure looks like a pump quality problem when it is really an alignment problem.
Pumps are compact, do not deteriorate in storage and fit several ratings in the family. For a fleet, two on the shelf with gaskets and thermostat housing seals turn a week of downtime into an afternoon repair.
When a manufacturer issues a new pump number for the same engine, the reason is usually a supplier change, a revised seal or a different pulley to suit a new accessory layout. The pumping element itself rarely changes much, which is why two pumps can look identical and still not be interchangeable on the vehicle.
If the old pump has no readable number, compare the pulley diameter and the distance from the mounting face to the pulley centreline. Those two measurements identify the variant faster than any catalogue, and they can be taken with a ruler on the bench.
Browse the Weichai pump category, and pair the pump with the WP12 water pump 612630061060 or the WP12 full gasket kit 612600900279.
Compare the pulley diameter and offset, or send us a photo of the old pump.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop.
The pump comes with the hub.
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.
