CATEngine Parts

391-4638 Boom Cylinder Seal Kit — Cat 308E

This boom cylinder seal kit is essential for maintaining hydraulic system integrity, preventing fluid leaks and ensuring proper cylinder operation. Manufactured to OEM standards, these seals offer superior resistance to wear and pressure compared to degraded or damaged original seals. Operators may notice hydraulic fluid leaks around the boom cylinder, slow or jerky boom movements, or a loss of lifting capacity when this seal kit fails.

Boom Cylinder Seal Kit – Part No 391-4638 – CAT Spare Part
Part Specifications
BrandCAT
CategoryEngine Parts
ConditionAftermarket — OEM Specification
DispatchSame-day from Mumbai (before 3 PM IST)
GST InvoiceAvailable — all orders
Export DocsCommercial invoice, packing list, COO

Compatible Models

Always verify with serial number before ordering.

WhatsApp for Price & Availability☎ Call Mumbai Office

Parts Trading Company  ·  Mumbai, Est. 1956  ·  Same-day dispatch  ·  Ships worldwide  ·  GST invoice included

t>

Related CAT Parts

From the same category — may also be needed

5s-1601-5s1601
Hydraulic Pump 5S 1601
231-8132
Cabin Air Filter
1B8721
Woodruff Key
6l7813
Engine Parts Component
207-6806
Solenoid Valve
174-1494
Blower Motor

Browse all CAT Engine Parts →

Ship This Part To Your Location

DubaiSaudi ArabiaNigeriaKenyaSouth AfricaBangladeshMalaysiaGhanaQatarEgypt
India
MaharashtraGujaratTamil NaduRajasthanKarnatakaTelangana

Full shipping information on regional pages · Air freight 2–12 days · GST invoice for India

Installation & Application Notes

Inspect mating surfaces for wear before fitting. Use torque specs from service manual. Replace gaskets and seals as a set — reusing compressed gaskets causes oil leaks. Clean all oil passages with compressed air.

Always consult the OEM service manual for model-specific torque values and procedures. WhatsApp our technical team if you need fitment guidance.

Part TypeHydraulic Cylinder Seal Kit
MaterialNBR Rubber and Seals
ApplicationBoom Cylinder Hydraulic System
Service LifeReplace every 2,000 hrs or as needed
CompatibilityCAT 308E Excavator
ConditionNew — OEM specification aftermarket

Failure Symptoms

The first sign of a failing boom cylinder seal kit is typically visible hydraulic fluid leakage around the cylinder rod or barrel. If ignored, this can lead to a gradual loss of hydraulic pressure, resulting in slower or erratic boom movements and reduced lifting performance. Continued operation with leaking seals can cause internal cylinder damage and contamination of the hydraulic fluid.

Installation Tip

Ensure all cylinder components are meticulously cleaned before installing the new seals to prevent any dirt or debris from causing premature failure. Use a proper seal driver tool to avoid damaging the new seals during installation.

Service Note

When replacing the boom cylinder seal kit, inspect the cylinder rod for scoring or damage and check the hydraulic fluid level and condition.