| Parameter | Value / Specification |
|---|---|
| Maximum Operating Pressure | Up to 4,350 PSI (300 bar) |
| Temperature Range | -40°F to 225°F (-40°C to 107°C) |
| Fluid Compatibility | Mineral-based hydraulic oils, Komatsu Super Hydraulic Fluid (KSHV), synthetic HFDU fluids |
| Primary Seal Material | Polyurethane (AU), Cast Polyurethane (CU), Nitrile Rubber (NBR) |
| Seal Hardness (Dynamic) | 90-94 Shore A (Polyurethane) |
| Seal Hardness (Static) | 70 Shore A (NBR O-Rings) |
| Design Standard | Manufactured to meet or exceed Komatsu's original specifications |
| Komatsu Excavator Model | OEM Part Number | Cylinder Application |
|---|---|---|
| Komatsu PC160LC-7 | 707-99-38760 | Boom Cylinder |
| Note: | This kit is a direct replacement for Komatsu OEM part number 707-99-38760. It is designed specifically for the BOOM CYLINDER on the PC160LC-7 excavator model. Verify your machine's model and serial number before installation. |
| Component Name | Material | Color | Durometer | Function |
|---|---|---|---|---|
| Main Piston Seal (U-Cup) | Polyurethane (AU) | Brown | 94 Shore A | Primary dynamic pressure seal on piston |
| Rod Seal (Step Seal) | Cast Polyurethane (CU) | Black | 93 Shore A | Main rod seal for pressure retention |
| Wiper/Scraper (Heavy-Duty) | Polyurethane (PU) | Black | 90 Shore A | Excludes dirt, dust, and debris from rod |
| Buffer Ring | Polyurethane (CU) | Black | 90 Shore A | Absorbs pressure spikes to protect rod seal |
| O-Ring Kit (Assorted) | Nitrile Rubber (NBR) | Black | 70 Shore A | Static sealing for gland, end cap, and ports |
| Wear Ring / Guide Band | Glass-Filled PTFE | Dark Brown | N/A | Centralizes piston, prevents metal contact |
| Backup Rings | Nylon 6.6 | Tan | N/A | Prevents extrusion of static O-rings under pressure |
| Dust Seal | Polyurethane | Black | 85 Shore A | Secondary contaminant exclusion |
Main Piston Seal (U-Cup) – Qty: 1
Rod Seal (Step Seal) – Qty: 1
Wiper/Scraper (Heavy-Duty) – Qty: 1
Buffer Ring – Qty: 1
Wear Ring (Piston) – Qty: 1
Dust Seal – Qty: As required
Complete O-Ring & Backup Ring Set – Qty: 1 Set (All necessary sizes for gland, port, and fitting assembly)
Note: This kit provides a complete seal profile set designed to match the exact specifications of the original Komatsu 707-99-38760 boom cylinder kit for the PC160LC-7. An exploded diagram is included for correct assembly.
Full set of precision-molded static O-rings for all gland and port connections
Essential wear guide band to ensure smooth piston travel and minimize side load on seals
High-pressure nylon backup rings for critical O-ring applications
Excluded Items: This is a seal and wear component kit only. It does NOT include the piston, cylinder rod, barrel, gland nut, bearings, bolts, or any other metal parts or hardware.
Application Verification: Confirm 707-99-38760 is the correct part number for your PC160LC-7 boom cylinder using official Komatsu documentation.
System Depressurization: Park the excavator on level ground. Lower the boom and bucket fully to relieve all hydraulic pressure. Secure the boom or cylinder rod mechanically.
Clean Work Environment: Maintain meticulous cleanliness throughout the repair process. Excavator cylinders operate in harsh conditions; contamination control is essential.
Documented Disassembly: Carefully disassemble the boom cylinder. Photograph and note the exact order and orientation of all components, especially the seal stack in the gland.
Critical Metal Inspection: Inspect the cylinder rod for scratches, gouges, or corrosion. Check the cylinder bore (ID) for scoring, pitting, or excessive wear. Damaged metal components MUST be reconditioned or replaced prior to seal installation.
Lubricated Assembly: Soak all new elastomeric seals in clean hydraulic fluid. Lightly lubricate all seal grooves and sliding surfaces before installing new seals.
Proper Tool Use: Use seal installation tools (cone tools, picks, sleeves) to carefully install seals without cutting, stretching, or rolling them over sharp edges.
Torque to Specification: During reassembly, use a calibrated torque wrench. Adhere strictly to Komatsu's specified torque values and sequences for gland bolts or end caps.
System Testing: After assembly, perform a controlled pressure test to validate seal integrity before returning the machine to service.

MODEL-SPECIFIC APPLICATION: This kit is ONLY for the BOOM CYLINDER on the Komatsu PC160LC-7 excavator. Do not use on arm cylinders, bucket cylinders, or other models without verification.
METAL SURFACE CONDITION: This kit seals fluid between precision metal surfaces. It CANNOT repair a scored rod or a worn cylinder bore. Installation on damaged components will result in immediate, severe leakage.
CONTAMINATION CONTROL: Even microscopic debris introduced during assembly will act as an abrasive, destroying new seals. Maintain absolute cleanliness during installation.
BOOM SUPPORT HAZARD: The excavator boom must be fully lowered and supported. Never work on a cylinder that is under load or hydraulic pressure.
| Application Sector | Target Equipment | Cylinder Type | Symptoms Addressed |
|---|---|---|---|
| Heavy Excavation & Earthmoving | Komatsu PC160LC-7 | Boom Cylinder | Boom drift (sinking), visible hydraulic oil leakage from rod gland, slow or weak lifting power, oil spots under the machine |
| Mining & Quarry Operations | -7 Series Excavator | Boom Lift Control | Loss of lifting capacity, reduced machine productivity, increased hydraulic fluid consumption |
| Construction & Demolition | Medium Excavator Boom Cylinder | Hydraulic Implement Repair | Unplanned downtime, fluid contamination from failed seals, reduced cycle times |
| Equipment Maintenance | Scheduled Overhauls & Leak Repair | Boom Cylinder Rebuild | Restores factory sealing, cost-effective OEM alternative, prevents environmental contamination |
Maintenance Best Practices:
Regular Inspections: Frequently check boom cylinder rods for scratches, pitting, or signs of leakage
Timely Replacement: Replace worn seals promptly to prevent contamination of the entire hydraulic system
Fluid Quality: Use clean hydraulic fluid meeting Komatsu specifications to prolong seal life
Operating Conditions: Monitor pressures and temperatures to prevent extremes that could affect seal performance
Frequently Asked Questions
A. When will get the items after I place order?
Q. Once your payment is confirmed,we will arrange the goods within 1~4 days; if not in stock, we will inform you before placing the order?
A. If I only know the excavator model, but can not offer parts No.,what should I do ?
Q. If possible, you can send us pictures of old products, nameplate or the size for reference.
A. How can you guarantee the quality??
Q. We will 100% test the goods before delivery. We also support video inspection.
A. How long will it take to delivery to my address??
Q. The normal delivery time is 3-7 days, depending on which country you are in.?
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Q : By sea, air or express(DHL,Fedex,TNT, UPS, EMS etc.),Sometimes we will arrange as the customer's demand.
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Q. We usually packed by standard exported box or carton. And yes we can pack as per your requirement.
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Q: Of course, you will be offered a good discount for a big amount.
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Q:Our advantages: 100% quality assurance, develop and manufature follow original ones;Quick response within 24 hours; Small order allowed;Reasonable stock and timely delivery;Neutral packing, customized packing are allowed. Positive customer feedback from abroad market;Excellent after-sales service.
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