3678912 XCMG GR2605 motor grader o-ring

Technical Parameters

• Part Number: 3678912 (SEAL, O-RING)
• Brand: Cummins
• Type: Radial O-ring seal
• Size: M14 (nominal diameter 14mm)
• Material: Fluorine rubber (FKM), temp range -40°F to 400°F (-40°C to 204°C)
• Hardness: 70±5 Shore A
• Media: Engine oil, diesel, coolant
• Pressure: ≤ 870 PSI (60 bar)
• Surface: Smooth, flash ≤0.1mm
• Cross: 3678606, 3922794 (interchangeable)

Application Scenarios

• Engines: 6BT5.9, ISDE6.7, QSB6.7, ISL9, ISX15
• Vehicles: Dongfeng Kinland, Tianjin, Dali Shen
• Machinery: 18–26 ton loaders, bulldozers, graders
• Equipment: Mining, oilfield, marine generator sets
• Location: Oil cooler housing, oil galley plugs, filter base, rear gear housing
• Function: Seals oil passages, prevents leaks, maintains pressure

Common Faults & Troubleshooting

1. Oil Leakage, Low Pressure

• Cause: Hardening, deformation, damage, installation scratches
• Symptom: Seepage, high oil consumption, low pressure warning
• Fix: Inspect surfaces; replace 3678912; clean grooves

2. Seal Failure, Seepage

• Cause: Aging, heat deterioration, chemical attack, improper fit
• Symptom: Slow leaks after service, cold-start leaks
• Fix: Install genuine FKM seal; lubricate with oil; avoid twisting

3. Installation Damage, Leaks

• Cause: Rough grooves, twisted seal, over-stretching
• Symptom: Immediate leaks after replacement
• Fix: Deburr grooves; align properly; stretch <5%

4. High-Temp Hardening

• Cause: Overheating, poor material, degraded oil
• Symptom: Brittle, cracked, loss of sealing force
• Fix: Use 3678912 OEM seal; check cooling system