Power Steering Oil Pump Assembly 8-97946164-0 / 8979461640 For ISUZU D-MAX II TFR TFS (2012–2023) 4JK1 4JJ1 — OEM-Spec Hydraulic Pump, Direct Fit

The Power Steering Oil Pump Assembly with OEM references 8-97946164-0 / 8979461640 (and related variants 8-97946164-2 / 8979461642) is a verified replacement hydraulic steering pump for ISUZU D-MAX II (TFR, TFS) pickups built from 2012 to 2023, equipped with the 4JK1 (2.5L CRDi) and 4JJ1 (3.0L) diesel engines. This engine-driven hydraulic pump pressurizes the power steering fluid, delivering the hydraulic assist that reduces steering effort and provides precise, responsive steering feel.

The pump is a complete assembly that mounts to the engine and is driven by the accessory belt. It draws fluid from the power steering reservoir, pressurizes it, and delivers it to the steering gear, where the pressure acts on the internal piston to assist the driver's steering input. A failing pump manifests as heavy steering effort, whining or groaning noise during turning, fluid leaks, or a complete loss of power assist — all of which directly impact vehicle safety, drivability, and driver fatigue. This unit is an OEM-specification aftermarket replacement, supplied as a brand-new assembly with a reference 1-year warranty from the supplying channel.

This is the hydraulic vane pump driven by the engine accessory belt. It is not an electric power steering (EPS) motor, not a steering rack, and not a steering gear. The D-MAX II platform uses hydraulic power steering, and this pump is the pressure source for that system. Confirm the vehicle's steering system type before ordering.

The pump is confirmed for the D-MAX II (TFR, TFS) platform from 2012/06 to 2023/12. The D-MAX I (2002–2012) may use a different pump reference — do not assume interchangeability across the D-MAX I / D-MAX II boundary without VIN confirmation. The related reference 8-97946-698-0 / 8979466980 is also documented for certain applications within the same platform family, and confirming the original unit's marking is essential before cross-application.

The pump is confirmed for 4JK1 (2.5L CRDi, 120 kW / 163 PS) and 4JJ1 (3.0L) engines. Both engines share the same power steering pump architecture in the D-MAX II platform, but engine-specific brackets or pulley configurations may vary. Confirm the engine code and VIN for final verification.

• OE Reference Group Verified: 8-97946164-0, 8979461640, 8-97946164-2, 8979461642 are consistently grouped as interchangeable or related references for the D-MAX II 4JK1/4JJ1 power steering pump across multiple supplier catalogs and OEM parts listings.
• Related Reference Family Verified: 8-97946-698-0 / 8979466980 is documented as an assembly-part variant within the same power steering pump diagram family for the TFR/TFS platform.
• Vehicle & Engine Coverage Verified: ISUZU D-MAX II (TFR, TFS) 2012/06–2023/12, 4JK1 / 4JJ1, 2.5 CRDi (120 kW / 163 PS) — confirmed across FridayParts fitment data and OEM parts catalog listings. 4JJ1 engine association is also confirmed for the wider D-MAX platform.
• Genuine OEM Status Verified: The part number 8979461640 is confirmed as a genuine ISUZU part — "exactly the same as the one mounted at the factory when the vehicle was new."
• MOQ & Supply Reference: Sample order accepted; small orders welcomed; delivery within 3–5 days after deposit for in-stock items — confirmed by Bossgoo supplier terms.
• Pulley Diameter, Flow Rate, and Pressure Specification NOT Publicly Published: Accessible supplier data does not publish the pulley diameter, flow rate (L/min), or operating pressure (bar) for this exact pump. Confirm these specifications against the original unit or supplier technical data sheet if precision matching is required for steering feel or accessory belt compatibility.

• Heavy or stiff steering effort: The most common symptom. The pump cannot generate sufficient hydraulic pressure, requiring excessive force to turn the steering wheel — especially noticeable at low speeds or during parking maneuvers.
• Whining, groaning, or moaning noise during turning: A worn pump vane, air in the system, or a failing internal pressure regulator produces audible noise that changes with steering input and engine speed.
• Fluid leak at the pump body, shaft seal, or hose connections: External seal failure allows power steering fluid to escape, often visible as wetness or drips on the pump, accessory belt, and surrounding engine components.
• Intermittent or complete loss of power assist: The steering may momentarily stiffen or lose assist entirely, particularly under load or when the fluid is hot — a direct safety concern.
• Foamy or aerated power steering fluid: Air entering the system through a failed pump seal or a low fluid level causes foaming, which reduces hydraulic efficiency and can damage the steering gear.
• Metal debris or glitter in the power steering fluid: Advanced internal pump wear produces metallic particles that circulate through the system, accelerating wear on the steering gear and seals.
• Squealing accessory belt: A seized or high-drag pump pulley can cause the accessory belt to slip and squeal, especially at start-up or under load.

• Platform generation is the first check: This pump is confirmed for D-MAX II (2012–2023). The D-MAX I (2002–2012) may use a different pump reference. Provide the VIN for final confirmation when crossing the D-MAX I / D-MAX II boundary.
• Engine and pulley configuration: While both 4JK1 and 4JJ1 are covered, confirm the engine code and inspect the original pump's pulley — belt routing and pulley offset must match for correct accessory drive function.
• Reference-family verification: 8-97946164-2 / 8979461642 and 8-97946-698-0 / 8979466980 are grouped as related/assembly-part variants. Read the original pump's marking where possible before ordering, and ensure the supplied reference matches the ordered reference.
• Reservoir provision: Some supply channels include the power steering fluid reservoir with the pump; others supply the pump only. Confirm package contents at inquiry — a missing reservoir prevents the vehicle from being returned to service until one is sourced.

1. 1Confirm the required part first: Verify that the replacement pump's pulley, mounting bracket, and pressure/return port configuration match the original unit. Confirm whether a reservoir is included or must be reused.
2. 2Safety first: Park on level ground, engage the parking brake, and chock the wheels. Disconnect the battery negative terminal.
3. 3Drain the power steering fluid: Place a drain pan underneath, disconnect the return hose from the pump, and allow the fluid to drain. Do not reuse the drained fluid — contaminated fluid can damage the new pump and steering gear.
4. 4Remove the accessory belt: Relieve belt tension and remove the belt from the pump pulley. Note the belt routing for reassembly.
5. 5Disconnect the pressure line and return hose: Disconnect the high-pressure line and return hose from the pump. Plug the lines immediately to prevent contamination.
6. 6Remove the old pump: Unbolt the pump from its mounting bracket. Support the pump weight before removing the final bolt.
7. 7Transfer the reservoir and pulley (if applicable): If the replacement is supplied without a reservoir or pulley, transfer the original components. Inspect the pulley for wear before reusing.
8. 8Install the new pump: Position the 8-97946164-0 pump on the mounting bracket. Install the mounting bolts and torque to the workshop manual specification.
9. 9Reconnect the lines and belt: Reconnect the pressure line and return hose. Reinstall the accessory belt according to the recorded routing.
10. 10Fill and bleed the system: Fill the reservoir with the ISUZU-recommended power steering fluid. Bleed the system by turning the steering wheel lock-to-lock several times with the engine idling, adding fluid as needed. Do not hold the wheel at full lock for more than a few seconds during bleeding.
11. 11Check for leaks and verify assist: Inspect for leaks at the pump, lines, and fittings. Confirm that steering assist is present and that there is no abnormal noise. Road-test at low speed before returning the vehicle to service.

• Check the power steering fluid level at every engine oil change or every 10,000–15,000 km — a dropping level indicates a leak that requires immediate attention.
• Inspect the accessory belt for cracks, glazing, and correct tension at every service — a slipping belt reduces pump output and can cause steering assist loss.
• Flush the power steering fluid according to the ISUZU schedule (typically every 40,000–60,000 km or when the fluid becomes dark or contaminated). Degraded fluid accelerates pump and steering gear wear.
• Avoid holding the steering at full lock — this places maximum load on the pump and can overheat the fluid, especially during parking maneuvers.

• Standard packing: Neutral white box / brown carton (supplier reference); customer-branded packaging available with authorization.
• Package contents: 1 × Power Steering Oil Pump Assembly. Reservoir and pulley inclusion varies by supply channel — confirm exact package contents at inquiry.
• Set options: Pump only (standard) / pump + reservoir (where available) — specify at inquiry.
• Suitable for: ISUZU D-MAX II / TFR / TFS power steering and hydraulic system repair shops, pickup fleet maintenance departments, steering system specialists, spare parts distributors, and export wholesalers.