Аксиально поршневой насос Nachi PVD-2B-31P-11AG-5053F 20/925683 для мини-экскаватора JCB 8025ZTS, 8030ZTS, 8035ZTS

1. Product Identification
Component: Main Hydraulic Variable Displacement Axial Piston Pump Assembly

Manufacturer Model Number: Nachi PVD-2B-31P-11AG-5053F (PVD Series Architecture)

JCB OEM Part Numbers: 20/925683, 20/925685, 333/P8281 (20925683, 20925685, 333P8281)

Machine Compatibility:

JCB 8025 ZTS (Zero Tail Swing)

JCB 8030 ZTS

JCB 8035 ZTS Mini Excavator

Condition: Genuine Original New / Premium OEM Specification Equivalent

2. Technical Specifications
Pump Type: Variable Displacement Axial Piston Pump with Integrated Gear Section

Flow & Pressure Performance: Factory-engineered displacement thresholds, flow profile, and operating pressure curves specifically matched to JCB 2.5 to 3.5-ton mini excavator hydraulic circuits.

Integrated Control Network: Features integrated load-sensing regulators to balance fluid delivery across multi-function digging, tracking, and swing operations without engine lugging.

Interface Mount: Precision mounting flange with heavy-duty input spline shaft designed to couple directly with the engine flywheel dampener drive.

3. Critical Installation Requirements
Hydraulic Pump Housing Priming (Mandatory)
Before starting the engine, manually fill the main pump casing with clean, fresh hydraulic fluid through its highest case drain port. Running an axial piston pump dry—even for a few seconds—will score the valve plate and piston slippers, causing immediate total pressure loss.

Air Bleeding & Initial Startup Procedure
After installation, loosen the air bleed port on top of the pump housing. Crank the engine with the fuel supply disabled until clear, bubble-free oil flows from the port, then retighten. Allow the machine to idle under no load for 10 to 15 minutes to purge any trapped air from the hydraulic loop.

Fluid & System Decontamination
If replacing a pump that suffered internal mechanical failure, completely drain and clean the main hydraulic oil reservoir, flush all circuit lines, and clean the oil cooler. Replace all return and suction filter elements before starting the engine.

Pilot & Main Relief Pressure Inspection
Verify system pressure relief valve settings upon startup. Incorrect pressure settings can lead to sluggish hydraulic response, circuit overheating, or engine stalling under heavy load.

4. Frequently Asked Questions (FAQ)
Q: Are JCB part numbers 20/925683, 20/925685, and 333/P8281 fully interchangeable?
A: Yes. These part numbers represent standard JCB factory revisions, supersessions, and catalog updates across the 8025ZTS, 8030ZTS, and 8035ZTS model generations. All cross-reference to the Nachi PVD-2B-31P platform with identical mounting dimensions and hydraulic specs.

Q: My JCB 8030ZTS loses speed or bogs down the engine during combined track and boom functions. Is the pump failing?
A: Engine lugging or slow multi-function response usually indicates worn internal valve plates or sticking load-sensing pump regulators failing to adjust output under load. Replacing the main pump assembly restores factory hydraulic power balance.

Q: Does the unit arrive complete with the rear gear pump section attached?
A: Yes. The unit comes fully assembled as a single integrated pump assembly, including the main axial piston pump section, factory-adjusted regulator blocks, and the auxiliary gear pump section.

5. Shipping & Logistics
Packaging: Preserved with rust-inhibiting storage oil, fitted with heavy-duty port plugs, and packed inside an export-safe protective crate or box.

Transit Time: Global express air freight via DHL/FedEx/UPS typically delivers within 3 to 7 business days directly to your workshop or job site.