Product Details
Blogs List
How to Find the Best Allison Transmission ...
2025-11-05 Comments Off on How to Find the Best Allison Transmission Spare Parts Supplier in China?Need More Information?
We’re happy to help you find the best option for your application.
C3929457 XCMG GR2605 motor grader O-ring
Part Number: C3929457 (3929457)
Alternate Name: Regulator Valve Seal, Bypass Valve O-Ring
Material: High-Performance Nitrile Rubber (NBR, Mineral Oil Resistant, High-Temp Resistant)
Dimensions: ID ~18.7mm (0.737″), Cross-Section ~3.5mm
Operating Pressure: ≤7bar
Share:
Product Details:
C3929457 XCMG GR2605 motor grader O-ring
C3929457 (3929457) is a genuine Cummins O-Ring Seal for Oil Pressure Regulator/Bypass Valve, a critical sealing component in the lubrication system for B/ISB/QSB series engines. Molded from high-performance Nitrile Rubber (NBR), it features oil resistance, high-temperature resistance, and low compression set. It effectively seals the gap between the regulator/bypass valve and the oil filter head to prevent oil leakage and pressure loss, ensuring stable system pressure.
Technical Parameters
Part Number: C3929457 (3929457)
Alternate Name: Regulator Valve Seal, Bypass Valve O-Ring
Material: High-Performance Nitrile Rubber (NBR, Mineral Oil Resistant, High-Temp Resistant)
Dimensions: ID ~18.7mm (0.737″), Cross-Section ~3.5mm
Operating Pressure: ≤7bar
Operating Temperature: -40℃~150℃
Hardness: Shore A 70±5
Cross Reference: M-3929457 (Interstate-McBee)
Location: Sealing Surface between Regulator/Bypass Valve and Oil Filter Head
Standard: Cummins OEM, ISO 9001, TS16949
Application
Applicable Engines: Cummins 4B3.9, 6BT5.9, 6B5.9, ISB4.5, ISB6.7, QSB4.5, QSB5.9, QSB6.7 Full Series.
Equipment:
- Commercial Vehicles: Dongfeng Tianlong, Tianjin, Foton Aumark, JAC, FAW J6, Dodge Ram 2500/3500
- Construction Machinery: Komatsu PC200-8, Hitachi ZX200, Kobelco SK210, LiuGong CLG922, XCMG XE215
- Generator Sets: 50–220kW Cummins Diesel Gensets
- Industrial Equipment: Air Compressors, Pumps, Marine Engines, Oilfield Machinery, Forklifts
Common Faults & Troubleshooting
1. Oil Leakage (Most Common)
- Causes: Aging/ hardening of seal, compression set, improper installation (twisted/side-loaded), worn/plunger scoring
- Symptoms: Seepage/drips around oil filter head/regulator, low oil pressure, oil stains on ground
- Solution: Replace with genuine C3929457 O-ring; clean regulator chamber and plunger; ensure no distortion during assembly.
2. Abnormal Oil Pressure
- Causes: Seal failure causing pressure loss, stuck regulator valve, clogged galleries
- Symptoms: Low idle pressure (<2.5bar), low acceleration pressure (<4.5bar), oil warning light, engine noise, increased wear
- Solution: Replace C3929457 O-ring; clean/replace regulator/bypass valve; clear galleries; change oil filter.
3. Seal Damage/Distortion
- Causes: Over-torqued assembly, overpressure shock, high-temperature aging, debris entrapment
- Symptoms: Seal breakage, expansion, distortion, seal failure, pressure fluctuation
- Solution: Replace C3929457 O-ring immediately; check regulator spring (C3925009) and plunger; replace regulator assembly if needed; spec torque during installation.
Get a personalized quote now
1 3955034 Oil Filter Seat
2 3974127 Filter Seat Gasket
3 C3901445 hexagonal flange bolt
4 C3906619 plug
5 C3925009 compression spring
6 C3929457 O-ring seal
7 C3936365 pressure reducing valve
8 C3946947 plug
9 C3947287 oil pressure regulating valve plunger
10 C3975818 oil cooler core
11 D2830559 oil cooler core sealing gasket
*For other spare parts procurement needs, please contact us!
