Model: WP9
Part Number: 1001273030
Brands: Weichai Power
Engine Model: WP9, WP9H, WP9G
Engine Type: Diesel
Scope of application: heavy trucks, buses, construction machinery, generator sets
The WP9 sits between the mid-range and heavy-duty engines in the Weichai range, used where a 7 or 8-litre unit is not quite enough and a 12 or 13-litre is too heavy or too thirsty. Part 1001273030 is the belt-driven coolant pump for this family, circulating coolant through the block, head, oil cooler and radiator.
Because the WP9 often works at sustained load, the cooling system has little margin. A pump that is slightly weak will keep the engine cool on flat ground and let it climb on a long grade, and that pattern of intermittent overheating is the classic early symptom.
The pump fits WP9, WP9H and WP9G engines in heavy trucks, buses, loaders, excavators and generator sets. Industrial and marine variants can use a different pulley or inlet arrangement even when the pump body is the same casting, so confirm the engine plate and the old pump number before ordering.
The pump uses a cast iron housing, a precision cast impeller, a sealed bearing cartridge lubricated for life and a mechanical face seal. Each unit is checked on the bench before packing rather than only inspected visually.
Each pump ships with a new gasket and O-ring, hub protected so the seal survives transit.
Coolant weep from the drain hole is the first sign. Noise comes later, when the bearing has lost lubricant, and a wobbling fan is the last warning before collapse.
A collapsed bearing lets the fan contact the radiator, which turns a modest repair into an expensive one.
Most premature pump failures come from belt alignment rather than the pump itself. A worn tensioner, a misaligned idler or the wrong pulley offset side-loads the bearing continuously and the seal starts weeping within a few thousand kilometres. Check the belt path with a straight edge and replace any component with play before fitting the new pump.
Match the engine plate, the old pump number and the pulley type. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping. Getting the pulley wrong is the most common reason a correct pump fails in service, because a mismatched pulley destroys alignment on the first belt run.
Pumps last longest in clean systems with correct chemistry. Flush the radiator at interval, keep the coolant mixture in specification and replace the thermostat and pressure cap when due. Clean the core externally in dusty operations, since a blocked core raises coolant temperature and shortens seal life even when the pump is healthy.
Pumps are compact and do not deteriorate in storage, which makes them sensible spares. For fleets, keep two on the shelf together with gaskets and thermostat housing seals so a repair is completed in a single visit. Shipping is cheap relative to the cost of a truck standing for a week waiting on a part.
Coolant that disappears without a visible external leak is a different problem from a leaking pump, and the two are often confused. A weeping pump usually leaves white residue around the housing and a damp spot under the drain hole. A head gasket failure consumes coolant without trace, sometimes with bubbles in the radiator and a sweet smell at the exhaust.
Pressure test the cooling system before replacing the pump. If it holds pressure and the level still drops, the loss is going through the engine rather than onto the ground, and the head should be checked rather than the pump replaced.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop. Coolant loss leads to overheating and head damage.
The pump comes with the hub. Tell us if you need the complete assembly.
Remove the belt and spin the pump by hand. Roughness or play confirms the bearing.
Browse the Weichai pump category, and pair the pump with the WP9 cylinder head 1001677070 or the WP9 full gasket kit 11600040014.
Weichai WP9 Water Pump (1001273030). This pump maintains coolant velocity across the liners and through the head. Poor flow shows up as a temperature rise under load, not at idle.
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 1001 belong to the numeric series introduced as the older 61xx numbers were superseded. Both numbers may describe the same physical part. On this engine, confirm the WP9 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. 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: WP9, WP9H, WP9G, 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 precision cast impeller, a sealed bearing cartridge lubricated for life and a mechanical face seal. Each unit is checked on the bench before packing rather than only inspected visually.
Each pump ships with a new gasket and O-ring, hub protected so the seal survives transit.
Coolant weep from the drain hole is the first sign. Noise comes later, when the bearing has lost lubricant, and a wobbling fan is the last warning before collapse.
A collapsed bearing lets the fan contact the radiator, which turns a modest repair into an expensive one.
Most premature pump failures come from belt alignment rather than the pump itself. A worn tensioner, a misaligned idler or the wrong pulley offset side-loads the bearing continuously and the seal starts weeping within a few thousand kilometres. Check the belt path with a straight edge and replace any component with play before fitting the new pump.
Match the engine plate, the old pump number and the pulley type. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping. Getting the pulley wrong is the most common reason a correct pump fails in service, because a mismatched pulley destroys alignment on the first belt run.
Pumps last longest in clean systems with correct chemistry. Flush the radiator at interval, keep the coolant mixture in specification and replace the thermostat and pressure cap when due. Clean the core externally in dusty operations, since a blocked core raises coolant temperature and shortens seal life even when the pump is healthy.
Pumps are compact and do not deteriorate in storage, which makes them sensible spares. For fleets, keep two on the shelf together with gaskets and thermostat housing seals so a repair is completed in a single visit. Shipping is cheap relative to the cost of a truck standing for a week waiting on a part.
Coolant that disappears without a visible external leak is a different problem from a leaking pump, and the two are often confused. A weeping pump usually leaves white residue around the housing and a damp spot under the drain hole. A head gasket failure consumes coolant without trace, sometimes with bubbles in the radiator and a sweet smell at the exhaust.
Pressure test the cooling system before replacing the pump. If it holds pressure and the level still drops, the loss is going through the engine rather than onto the ground, and the head should be checked rather than the pump replaced.
Browse the Weichai pump category, and pair the pump with the WP9 cylinder head 1001677070 or the WP9 full gasket kit 11600040014.
Yes, the gasket and O-ring are supplied.
Only to reach a workshop. Coolant loss leads to overheating and head damage.
The pump comes with the hub. Tell us if you need the complete assembly.
Remove the belt and spin the pump by hand. Roughness or play confirms the bearing.
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.
