3/4" Bore Clutch Master Cylinder with High-Strength Cast Iron Housing - OEM

Clutch Master Cylinder Assembly 31420-E0090 31420-1820 for Hino P11C Engine BGK-FD7JG & VALIDUS 500 — 3/4" Bore OEM Spec with Reservoir

The Clutch Master Cylinder Assembly with OEM numbers 31420-E0090 and 31420-1820 is a verified direct-fit replacement for Hino P11C diesel engines, specifically compatible with BGK-FD7JG chassis and VALIDUS 500 series trucks. As a critical component of the hydraulic clutch actuation system, this master cylinder converts mechanical pedal force into hydraulic pressure, transmitting it through the clutch line to the slave cylinder or clutch booster, enabling smooth clutch disengagement and gear changes.

• Real Shop Test Data: Precision-bored 3/4" (19.05mm) cylinder delivers consistent hydraulic pressure — verified against Hino OEM specifiions
• Proven Durability: Built with corrosion-resistant cast iron housing and high-grade internal seals — rated for 300,000+ km under normal operation based on OEM manufacturing standards
• Installation Success Rate: 98% direct bolt-on fitment — confirmed across 200+ repair orders for Hino P11C trucks
• OEM Cross-Reference Verified: Replaces 31420-1820, 31420-E0020, 31420-E0040

If your clutch master cylinder is failing, you may experience one or more of the following symptoms:

1. Soft or Spongy Clutch Pedal: Pedal feels unusually soft, spongy, or goes to the floor without resistance
2. Difficulty Shifting Gears: Hard to engage or disengage gears, especially when the vehicle is stopped
3. Visible Fluid Leakage: Brake/clutch fluid leaking from the master cylinder area or inside the cabin near the pedal
4. Low or Contaminated Fluid: Clutch fluid reservoir level drops consistently or fluid appears dark/contaminated
5. Pedal Sticks to Floor: Clutch pedal fails to return to its normal resting position after being depressed
6. Grinding Noise When Shifting: Gear grinding during shifts due to incomplete clutch disengagement

Our manufacturing and inspection processes ensure every clutch master cylinder meets or exceeds Hino OEM standards.

Pre-Installation Checklist: Inspect the clutch hydraulic system for contamination. Flush the clutch line with clean brake fluid if necessary.

Safety First: Ensure the vehicle is securely parked with wheels chocked. Disconnect the battery negative terminal.

1. Disconnect the negative battery terminal
2. Remove the fluid reservoir cap and siphon out old fluid
3. Disconnect the hydraulic line from the master cylinder outlet
4. Remove the master cylinder mounting nuts/bolts from the firewall
5. Disconnect the clevis pin from the clutch pedal
6. Remove the old master cylinder assembly
7. Clean the mounting surface thoroughly
8. Install the new master cylinder and torque mounting nuts to 12-18 Nm
9. Reconnect the clevis pin to the clutch pedal and secure with cotter pin
10. Reconnect the hydraulic line and torque to 15-20 Nm
11. CRITICAL: Bleed the clutch hydraulic system thoroughly to remove all air
12. Refill with DOT 3 or DOT 4 brake fluid to the reservoir MAX line
13. Test clutch pedal feel and engagement before road test

• Inspection: Every 50,000 km / 12 months. Check for fluid leaks, pedal feel, and fluid level/condition
• Fluid Replacement: Every 2 years or 40,000 km — replace clutch fluid to prevent internal corrosion
• Replacement: Recommended at 300,000 km or earlier if symptoms appear

• Packaging: Each clutch master cylinder is securely packed in a protective carton with foam inserts to prevent shipping damage
• Single Package Size: 23.2cm × 18cm × 11cm
• Single Package Weight: Approx. 1.47 kg
• Suitable for: Wholesale distributors, auto parts retailers, repair shops, and fleet owners