مضخة هيدروليكية Caterpillar 397-3681 3973681 لـ حفارة Caterpillar 335F

335F Hydraulic Pump for CAT Excavator spare parts 397-3681 3973681 Aftermarket

Product Overview

This aftermarket variable displacement axial piston main hydraulic pump acts as the core power component for Caterpillar 335F 34‑ton class medium‑large crawler excavator. It converts engine mechanical power into high‑pressure regulated hydraulic flow to drive boom, arm, bucket, travel motors and swing motor for all working movements of the machine. The 335F is widely applied in heavy earthmoving, quarry exploitation, road construction, site development and medium‑load demolition projects. Under long‑time heavy‑duty construction and severe site conditions, internal components including cylinder block, piston shoe assembly, valve plate and retainer plate will suffer progressive wear. Common fault performances contain insufficient digging force, slow implement response, high hydraulic oil temperature, abnormal knocking noise and serious internal pump leakage. Produced according to original sample and drawing data, this aftermarket main pump realizes direct replacement installation, restores the machine's working efficiency, and prevents secondary damage to other hydraulic components such as control valve and hydraulic motor.

Core Advantages

1. Optimized friction pair material adapts to medium‑large excavator heavy‑cycle working condition
Key friction parts adopt high‑strength alloy material with precise heat‑treatment processing. Improved surface hardness strengthens anti‑abrasion capacity against tiny impurities mixed in hydraulic oil. It can keep stable pressure output under continuous heavy‑load excavation, frequent compound action and long‑duration idling which often occur in earthmoving and quarry operation sites.

2. Pre‑adjusted power regulator matches original machine power curve
The built‑in power regulator is debugged referring to original equipment parameters. It reasonably distributes engine power between travelling and working devices, lowers overflow energy loss, reduces system heat generation. Operators can obtain smooth and coordinated movement during digging, lifting and slewing without obvious power lag.

3. Complete dimensional interchangeability reduces on‑site repair cycle
Mounting hole positions, input spline specification, oil port size and regulator installation dimension are fully matched with original pump referenced by part numbers 397‑3681 and 3973681. Repair technicians can finish replacement work on machine without extra machining, cutting or pipeline modification. It effectively shortens equipment downtime for repair shops, project fleets and spare parts dealers serving the 335F installed base.

4. Strictly controlled assembly clearance suppresses internal leakage
Each mating component goes through precision grinding procedure. Assembly clearance is controlled within aftermarket qualified tolerance range. It greatly improves the problem of internal bypass leakage caused by component wear, solves typical failures of weak digging power and slow cylinder movement, and extends maintenance cycle of the whole hydraulic system.

5. Cost‑effective aftermarket solution for global construction machinery supply chain
With reliable practical performance and competitive purchasing cost, this hydraulic pump is suitable for Caterpillar equipment owners, local repair garages and overseas spare‑part wholesalers. It provides stable support for medium‑large sized excavator overhaul and maintenance projects.

Manufacturing & Quality Control

Our factory focuses on manufacturing main hydraulic pumps for medium‑large construction excavators. The whole quality control flow covers incoming raw material inspection, key dimension measurement, heat‑treatment hardness detection, sub‑part screening and finished product hydraulic bench test. Every finished pump will pass pressure holding test, flow detection and noise inspection before delivery to filter out defective products. After professional anti‑rust treatment, products are wrapped with shock‑proof cushion material and packed in export‑grade wooden cases, to avoid collision damage and damp corrosion during long‑distance sea and land transportation. Sample testing order, small‑batch trial order and large‑volume bulk order are all acceptable for global customers.

Frequently Asked Questions

Q1: What symptoms remind users to inspect or replace the main hydraulic pump?
A: When your 335F excavator shows obvious insufficient digging capacity, slow boom and bucket action, continuous high hydraulic oil temperature, abnormal knocking noise from pump chamber, and these faults cannot be solved by adjusting regulator or replacing filter elements, you need to inspect or change the main pump.

Q2: Can this aftermarket pump be directly installed on CAT 335F?
A: This pump is designed as aftermarket replacement for Caterpillar 335F with OEM reference numbers 397‑3681 and 3973681. Please confirm your old pump model and machine configuration before placing order; different production periods may be equipped with different hydraulic pump assemblies even for the same excavator model.

Q3: What important operations need to be completed after replacing the hydraulic pump?
A: Thoroughly clean the hydraulic oil tank, replace all related hydraulic filter elements and fill in hydraulic oil that meets the equipment specification. Fully release trapped air inside hydraulic pipelines after installation. Carry out low‑speed no‑load running‑in firstly, then perform step‑by‑step load test. Do not run full‑load heavy‑duty work immediately after finishing pump installation.

Q4: About product warranty scope
A: Our warranty covers product defects caused by raw material problems and manufacturing errors. Failures caused by hydraulic oil pollution, wrong oil viscosity, foreign matter entering pump interior, long‑term over‑load operation and wrong installation steps are not included within warranty range. Please complete overhaul work following Caterpillar official service maintenance requirements.