Model: WP9
Part Number: 611600070100
Brands: Weichai Power
Engine Model: WP9, WP9H, WP9G
Engine Type: Diesel
Scope of application: heavy trucks, buses, construction machinery, generator sets
A nine-litre diesel circulates oil through main and rod bearings, the turbocharger, the valve train and the piston cooling jets. Part 611600070100 is the gear-type oil pump for the Weichai WP9, driven from the front of the engine and fitted with an integrated relief valve. It must deliver volume at idle and hold pressure at rated speed without exceeding the limit set by the valve.
When the pump wears, the first sign is not a warning light but a slow drop in pressure at hot idle, followed by rising oil temperature and eventually a knock under load. Replacing the pump during an overhaul is inexpensive compared with replacing a crankshaft.
The pump fits WP9, WP9H and WP9G engines in heavy trucks, buses, loaders, excavators and generator sets. Confirm the engine plate and the old pump number before ordering. Industrial and marine variants can use a different pick-up arrangement even when the pump body looks identical.
Every pump is run on a test bench rather than only inspected. Flow is measured at rated speed against the original curve, the relief valve is opened and its pressure recorded, gear backlash and end clearance are measured, and the housing and joints are leak tested.
Pumps ship oiled and plugged, with the drive gear fitted and keyed as original.
Low oil pressure is the headline symptom, but the details matter. Pressure that is low only when hot points to worn bearings as much as a worn pump. Pressure that recovers instantly with engine speed points to the relief valve or pump clearances.
Confirm with a mechanical gauge at the main gallery. A blocked strainer imitates a worn pump exactly.
Check oil level and condition, replace the filter, inspect the strainer, then measure pressure with a mechanical gauge. Only after those steps should the relief valve and the pump come under suspicion. Recording cold idle, hot idle and rated speed gives a clear diagnosis and avoids buying parts that are not needed.
Match the part number, the engine rating and the drive type. If the engine has been rebuilt with a replacement front cover, check that the mounting face and drive gear match. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping.
On these engines the pump also supplies the piston cooling jets. A pump that delivers pressure but not enough volume still allows crown temperatures to climb, and the damage appears as a scored or cracked piston rather than low oil pressure. If pistons have failed without an obvious cause, measure flow before blaming the pistons.
After assembly, measure pressure at three points: cold idle, hot idle and rated speed, then compare with specification. A pump that holds rated pressure but drops at hot idle usually has worn bearings downstream. Also check the filter bypass and the oil cooler for restriction.
Most premature failures come from contaminated oil. Use the specified grade, change it at the severe-duty interval and never run with a leaking injector that thins the oil with diesel. Keep the cooling system healthy, because sustained overheating reduces oil film strength at the bearings.
Yes, the mounting gasket and O-ring are supplied.
Yes. A blocked strainer, stuck relief valve, worn bearings or a faulty sender all mimic pump failure.
The pump comes with its drive gear fitted and timed as original.
At every major overhaul, or whenever the front cover is removed.
Browse the Weichai pump category, and pair the pump with the WP9 crankshaft 1000408941 or the WP9 engine overhaul kit 611600030018.
Weichai WP9 Oil Pump (611600070100). Lubrication starts here. The gear set, relief valve and drive must all match the housing, and a mismatch shows up as low pressure from the first start.
Ask whether the relief valve is set for your application. The valve is part of the assembly on these units and its setting is not adjustable in service.
Numbers beginning 6116 are used on the WP9 and later WD615 variants. The prefix alone does not pin the revision down; the engine plate and the old part number together do. On this engine, confirm the WP9 application against the engine plate before ordering.
Prime the pump before the first start and confirm oil pressure at the gauge before allowing the engine to run. Never crank a fresh rebuild hoping pressure will arrive.
Ordering note. Lead time depends on whether the item is in stock or has to be produced; the position is confirmed before the order is accepted rather than after payment.
Related reading: Oil Pump Diagnosis: Low Pressure, Wear and Replacement
| 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 |
Every pump is run on a test bench rather than only inspected. Flow is measured at rated speed against the original curve, the relief valve is opened and its pressure recorded, gear backlash and end clearance are measured, and the housing and joints are leak tested.
Pumps ship oiled and plugged, with the drive gear fitted and keyed as original.
Low oil pressure is the headline symptom, but the details matter. Pressure that is low only when hot points to worn bearings as much as a worn pump. Pressure that recovers instantly with engine speed points to the relief valve or pump clearances.
Confirm with a mechanical gauge at the main gallery. A blocked strainer imitates a worn pump exactly.
Check oil level and condition, replace the filter, inspect the strainer, then measure pressure with a mechanical gauge. Only after those steps should the relief valve and the pump come under suspicion. Recording cold idle, hot idle and rated speed gives a clear diagnosis and avoids buying parts that are not needed.
Match the part number, the engine rating and the drive type. If the engine has been rebuilt with a replacement front cover, check that the mounting face and drive gear match. Send a photo of the old pump beside a ruler and we will confirm the casting before shipping.
On these engines the pump also supplies the piston cooling jets. A pump that delivers pressure but not enough volume still allows crown temperatures to climb, and the damage appears as a scored or cracked piston rather than low oil pressure. If pistons have failed without an obvious cause, measure flow before blaming the pistons.
After assembly, measure pressure at three points: cold idle, hot idle and rated speed, then compare with specification. A pump that holds rated pressure but drops at hot idle usually has worn bearings downstream. Also check the filter bypass and the oil cooler for restriction.
Most premature failures come from contaminated oil. Use the specified grade, change it at the severe-duty interval and never run with a leaking injector that thins the oil with diesel. Keep the cooling system healthy, because sustained overheating reduces oil film strength at the bearings.
Browse the Weichai pump category, and pair the pump with the WP9 crankshaft 1000408941 or the WP9 engine overhaul kit 611600030018.
Yes, the mounting gasket and O-ring are supplied.
Yes. A blocked strainer, stuck relief valve, worn bearings or a faulty sender all mimic pump failure.
The pump comes with its drive gear fitted and timed as original.
At every major overhaul, or whenever the front cover is removed.
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.
