Brake Master Cylinder Assembly 8-94441332-0 / 8944133200 For ISUZU NHR NKR NPR ELF (4JB1) — 1" (25.4mm) Bore, Aluminum, M10×1 Outlet, LHD

The Brake Master Cylinder Assembly with OEM references 8-94441332-0 / 8944133200 is a verified replacement hydraulic pressure generator for ISUZU NHR, NKR, NPR, and ELF light trucks equipped with the 4JB1 (2.8L) diesel engine, covering the 1985–2003 production span. This is the complete master cylinder assembly that converts brake pedal force into hydraulic pressure, transmitting it to the wheel cylinders or calipers to decelerate or stop the vehicle.

The unit is defined by a 1-inch (25.4 mm) piston bore, an aluminum cylinder body, and a 1 × M10×1.0 outlet thread. It is configured for Left-Hand Drive (LHD) vehicles and is confirmed to fit the ISUZU ELF (NHR5_) 2.8 D platform with the 4JB1 engine. The reservoir is not included with the cylinder in standard supply; the original reservoir must be transferred, or a separate reservoir sourced.

1. 1-Inch (25.4 mm) Bore — The 25.4 mm bore is the defining hydraulic specification. A different bore size will alter pedal effort and braking balance. Confirm the original unit's bore diameter before ordering.
2. Left-Hand Drive (LHD) — The cylinder is confirmed for LHD vehicles. Right-hand drive (RHD) applications may use a different port orientation or mounting configuration. Confirm the vehicle's steering configuration and VIN.
3. Reservoir Not Included — Standard supply is the cylinder assembly without the reservoir. The original reservoir, cap, and seals must be transferred, or a new reservoir sourced separately. Confirm reservoir inclusion at inquiry — a missing reservoir immobilizes the vehicle.

• VerifiedBore Diameter: 1-inch (25.4 mm) — confirmed across multiple independent technical listings for the 8-94441332-0 / 8-94441-332-0 reference.
• VerifiedOutlet Thread: 1 × M10×1.0 — confirmed by technical data specifying "M10x1" and 2 thread ports for the same reference family.
• VerifiedMaterial: Aluminum — confirmed by the technical specification (cylinder material: aluminum).
• VerifiedDrive Configuration: Left-Hand Drive (LHD) — confirmed by fitment data for left-hand drive vehicles.
• VerifiedVehicle & Engine Coverage: ISUZU ELF (NHR5_) 2.8 D, 4JB1, 1985–2003 — confirmed by fitment data. NKR and NPR coverage is referenced for the same master cylinder family. JAC 1040 / ISUZU 1040 cross-coverage is confirmed via the A51-TRA0050 cross-reference.
• VerifiedReservoir Inclusion: Without reservoir — confirmed by the technical specification.
• VerifiedCross-Reference Density: TRW PML278, ASHIKA 68-09-906, JAPANPARTS PF-906 / PF-906906, JAPKO 68906, and A51-TRA0050 are consistently grouped as interchangeable or related references for the 8-94441332-0 assembly.
• NoteNet Weight Not Publicly Disclosed for This Exact Reference: Accessible technical data does not publish a net weight for 8-94441332-0. One reference indicates that size, weight, and freight will be provided upon quotation. Confirm net weight at inquiry for freight planning.

• Sinking brake pedal at a stop: The pedal slowly creeps toward the floor while holding steady pressure — indicates internal seal bypass within the master cylinder.
• Spongy pedal that persists after bleeding: Air enters the system through a failed seal, and bleeding does not permanently remove the sponginess.
• Inconsistent pedal feel: The pedal may feel normal on one application and low or soft on the next, as internal seals intermittently fail to hold pressure.
• Brake fluid leak at the master cylinder body or pushrod end: External seal failure allows brake fluid to escape, often visible as wetness on the booster or firewall.
• Brake warning light illumination (without low fluid): A failing master cylinder can trigger the brake warning lamp even when the reservoir is at the correct level.
• Longer stopping distances / need to pump the pedal: As pressure retention degrades, the driver must pump the brake pedal repeatedly to build sufficient braking force.

• Bore diameter is the first check: This is a 1-inch (25.4 mm) bore. Confirm the original master cylinder's bore before ordering — a mismatched bore changes pedal effort and braking balance.
• LHD confirmed: This cylinder is configured for Left-Hand Drive. RHD applications may require a different port orientation or reference. Confirm the vehicle's steering configuration and VIN.
• Reservoir is not included: The standard supply is the cylinder assembly only. Confirm whether the original reservoir can be transferred or a new reservoir is required.
• Vehicle coverage: Core applications are NHR, NKR, NPR, and ELF with the 4JB1 engine. Provide the VIN for final confirmation in mixed-fleet applications.

1. 1Confirm the required part first: Verify the original master cylinder's bore diameter (25.4 mm), outlet thread (M10 × 1.0), and LHD configuration. Confirm whether the original reservoir is to be reused.
2. 2Bench-bleed the master cylinder: Clamp the cylinder in a vice with soft jaws and bleed it on the bench before installation to reduce in-vehicle bleeding time.
3. 3Disconnect the battery and brake lines: Disconnect the negative battery terminal. Place a drain pan underneath, disconnect the brake lines from the master cylinder, and plug the lines immediately to prevent contamination.
4. 4Remove the old master cylinder: Unbolt the master cylinder from the brake booster. Note the orientation of the pushrod and any spacers.
5. 5Transfer the reservoir (if applicable): If the replacement is supplied without a reservoir, carefully transfer the original reservoir and seals.
6. 6Install the new master cylinder: Position the 8-94441332-0 unit, connect the brake lines, and torque the mounting nuts to the workshop manual specification. Do not over-torque the hydraulic line fittings.
7. 7Bleed the brake system: Bleed the front and rear circuits according to the ISUZU procedure until clear, bubble-free fluid flows from each bleeder screw.
8. 8Test pedal feel and brake function: The pedal should be firm and should not sink under sustained pressure. Road-test at low speed before returning the vehicle to service.

• Inspect brake fluid at every service — contaminated or dark fluid accelerates master cylinder seal wear.
• Replace brake fluid every 2 years or according to the ISUZU schedule.
• Check for leaks at the master cylinder body, line fittings, and reservoir seal during routine inspection.
• Replace the master cylinder at the first sign of a sinking pedal or external leak — do not monitor a known-failing brake component on a commercial vehicle.

• Standard packing: Neutral carton or customer-requested packaging.
• Package contents: 1 × Brake Master Cylinder Assembly. Reservoir is not included in standard supply. Mounting hardware and brake fluid are not included unless explicitly stated. Confirm at inquiry.
• Set options: Cylinder only (standard) / cylinder + reservoir (where available) — specify at inquiry.
• Suitable for: ISUZU NHR / NKR / NPR / ELF brake system repair shops, JAC 1040 service providers, light commercial fleet maintenance departments, spare parts distributors, and export wholesalers.