Komatsu PC128US-1 Hydraulic Arm Cylinder 203-63-02722 108mm Bore 1160mm Stroke Aftermarket
Komatsu PC128US-1 Hydraulic Arm Cylinder | PN:203-63-02722 | Premium Aftermarket Replacement
1. Basic Product Info
This high-quality aftermarket hydraulic stick cylinder is precision manufactured as a direct OEM replacement for Komatsu PC128US-1 zero-tail excavator. As the core hydraulic actuator of front working equipment, it controls arm extension and retraction to complete excavation, material grabbing, loading and site leveling tasks. Widely used in urban narrow-space construction, pipeline laying, landscaping and small earthmoving projects.
All cylinders are strictly produced per Komatsu original technical drawings, with fully consistent mounting dimensions, pin pitch and hydraulic port layout. Direct bolt-on installation without cutting, welding or any on-site secondary modification.
| Item | Specification |
|---|---|
| Product Name | Hydraulic Arm (Stick) Cylinder |
| Applicable Model | Komatsu PC128US-1 Zero Tail Excavator |
| OEM Part Number | 203-63-02722 |
| Product Grade | Brand New High-Quality Aftermarket |
| Warranty | 12 months against manufacturing defects |
| MOQ | 1 unit, sufficient stock for immediate dispatch |
| QC Standard | ISO9001 certified, full hydraulic pressure test & cyclic fatigue test before shipment |
2. Core Technical Parameters
| # | Part No. | Description | Qty |
|---|---|---|---|
| G1 | (203-63-X9040) | CYLINDER GROUP,(SEE FIG.Y1620-11A0C) | 1 |
| G1 | (203-63-X2722) | CYLINDER GROUP,ARM (SEE FIG.Y1620-11A0) | 1 |
| G1 | (203-63-X2721) | CYLINDER GROUP,(SEE FIG.Y1620-11A0B) | |
| ---- | ==================== | ||
| 1 | 203-63-02722 | CYLINDER ASS'Y,ARM | 1 |
| 1 | 203-63-02721 | CYLINDER ASS'Y,ARM | 1 |
| 1 | 203-63-65142 | CYLINDER,ARM | 1 |
| 1 | 203-63-65141 | CYLINDER,ARM | 1 |
| 2 | 707-76-70240 | Bushing | 1 |
| 3 | 07145-00070 | SEAL,DUST? PISTON ROD | 2 |
| 4 | 707-71-32530 | COLLAR | 1 |
| 5 | 07000-15105 | O-RING (KIT) | 1 |
| 6 | 707-35-91150 | RING,BACK-UP (KIT) | 2 |
| 7 | 707-27-11971 | HEAD,CYLINDER | 1 |
| 8 | 707-52-90500 | Bushing | 1 |
| 9 | 707-51-75030 | PACKING,ROD (KIT) | 1 |
| 10 | 707-51-75630 | RING,BUFFER (KIT) | 1 |
| 11 | 07000-15105 | O-RING (KIT) | 1 |
| 12 | 707-35-91150 | RING,BACK-UP (KIT) | 1 |
| 13 | 144-63-94170 | SEAL,DUST (KIT) | 1 |
| 14 | 07179-13089 | RING, SNAP | 1 |
| 15 | 01010-81670 | BOLT,(WITH WEAR GUARD) | 12 |
| 16 | 01643-51645 | WASHER, SPRING | 12 |
| 17 | 203-63-65121 | ROD,PISTON | 1 |
| 18 | 707-71-60200 | PLUNGER | 1 |
| 19 | 04260-00635 | BOWL, CHECK VALVE | 11 |
| 20 | 707-71-91270 | Cap | 1 |
| 21 | 707-76-70240 | Bushing | 1 |
| 22 | 07145-00070 | SEAL,DUST? PISTON ROD | 2 |
| 23 | 707-71-60870 | PLUNGER | 1 |
| 24 | 707-36-11661 | Piston | 1 |
| 25 | 707-44-11280 | RING,(Y1620-01A1-19) | 1 |
| 26 | 707-39-11510 | RING,(Y1620-01A1-20) | 2 |
| 27 | 707-44-11920 | Ring | 2 |
| 28 | 01310-01216 | SCREW,NYLON | 1 |
| 29 | 07000-15070 | O-RING (KIT) | 1 |
| 30 | 707-35-90360 | RING,BACK-UP (KIT) | 2 |
| 30A | 707-83-13010 | Valve | 1 |
| 30B | 07750-01628 | Spring | 1 |
| 30C | 707-87-14070 | Plug | 1 |
| 30D | 07002-12034 | O-RING,(FOR WITHOUT BRAKE ASSISTOR) | 1 |
| 31 | 203-63-65171 | Tube | 1 |
| 32 | 707-87-13570 | Elbow | 1 |
| 33 | 07000-13025 | O-RING,(SEE FIG. H0311-01A0-30) | 2 |
| 34 | 01010-50850 | BOLT (KIT) | 4 |
| 35 | 01010-50855 | BOLT,(10M) | 4 |
| 36 | 01643-50823 | WASHER,(FOR SHIPPING) | 8 |
| 37 | 707-88-95360 | BAND (PAINT(2)) | 1 |
| 38 | 707-88-95510 | BRACKET (PAINT(2)) | 1 |
| 39 | 01010-51035 | BOLT,(FOR QUICK SHIFT) (MITSUBISHI) | 2 |
| 40 | 01643-51032 | WASHER, (WITHOUT EMERGENCY STEERING) | 2 |
| 41 | 07283-22236 | U-BOLT, TUBE CLAMP | 1 |
| 42 | 01599-01011 | NUT,(WITH UNDER MIRROR) | 2 |
| 43 | 01643-31032 | WASHER,(WITH AUTO EMERGENCY STEERING) | 2 |
| ---- | ==================== | ||
| K | 707-99-44230 | SERVICE KIT,ARM CYLINDER | 1 |
| K | 707-99-44220 | SERVICE KIT | 1 |
| Spec Item | Data |
|---|---|
| Bore Diameter | 108mm |
| Piston Rod Diameter | 72mm |
| Working Stroke | 1160mm |
| Rated Working Pressure | 31.4MPa |
| Factory Test Pressure | 47.1MPa (1.5 times rated working pressure) |
| Barrel Material | High-tensile seamless alloy steel with precision inner honing |
| Piston Rod | 40CrMo heat-treated steel, 28~32μm hard chrome plating, HRC68–72, excellent wear resistance & anti-deformation performance |
| Matching Seal Kit PN | 203-63-02722K |
| Working Temperature | -25℃ ~ +85℃ |
| Structure Feature | Double ear lugs with quenched copper wear bushings, built-in internal buffer to reduce end-stroke impact and noise |
3. Product Advantages
- 100% OEM Exact Fitment
All assembly sizes, lug spacing and oil port positions fully match original PN 203-63-02722 cylinder. Perfectly connected with arm linkages and hydraulic hoses for stable continuous medium-load operation in compact construction sites. - Optimized Reinforced Structure for Zero-Tail Machine
Thickened cylinder tube and connection lugs are tailored for frequent narrow-site operation, resisting periodic dynamic loads and minor collisions to extend service life effectively. - Multi-Round Strict Pre-Delivery Inspection
Each finished cylinder runs full-stroke reciprocating cycle test and high-pressure airtight leak detection, completely eliminating hidden internal and external oil leakage risks. - Remarkable Cost Performance
Delivers the same stability and service lifespan as genuine Komatsu OEM spare parts, cutting recurring procurement costs for repair shops and equipment rental fleets. - Flexible Global Logistics Support
In-stock items ship within 3 working days. Air freight for urgent breakdown orders; sea freight for low-cost bulk wholesale shipments to Africa, Southeast Asia and Middle East markets.
4. Supplier Brief
Our factory has over 10 years of professional experience in R&D and production of hydraulic cylinders for Komatsu PC US series short-tail excavators, including PC128US-1. We supply complete boom, arm and bucket cylinder assemblies with mature production craft and full-process strict quality control. Our aftermarket hydraulic cylinders are exported worldwide all year round, winning consistent trust and positive feedback from global spare parts dealers.
5. FAQ
Q1: Can this arm cylinder fit Komatsu PC128US-2 or PC138US machines?
A: No. Each Komatsu zero-tail excavator model uses exclusive part numbers and unique structural dimensions without interchangeability. Please confirm your complete machine model before ordering.
Q2: Does the standard package include matching seal repair kit?
A: Seal kit is not included in standard delivery. You can purchase the dedicated supporting seal kit separately, and we will offer a favorable combined order price.
Q3: How is the cylinder packed for long-distance sea transport?
A: Anti-rust oil filled into cylinder inner cavity, anti-rust grease evenly coated on piston rod surface. Wrapped with waterproof PE film and packed in reinforced export plywood cases to prevent collision, scratch and moisture damage during ocean transit.
Q4: Are there tiered volume discounts for full set cylinders (boom + arm + bucket)?
A: Yes. Complete working device cylinder set orders enjoy graded volume discounts. Consolidated container shipment service is available to reduce total logistics expenditure.
Q5: What after-sales service if oil leakage occurs within 12-month warranty?
A: Please provide clear photos of leakage position plus excavator serial number. We provide free seal replacement and professional remote troubleshooting guidance promptly.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.