5030-451 | Genuine Paccar® 3 Way Normally Closed Solenoid Valve

This prevents unintended flow of air, fuel, coolant, oil, or water, which could be dangerous.

Example:
In a truck, if the engine dies, the solenoid valve cuts off air to the fan clutch, disengaging it automatically — avoiding mechanical stress or battery drain.

2. Energy Efficiency

It only uses electricity when flow is needed (to open the valve).
No power is required to keep it closed.

3. Precise Flow Control

Used in systems that need to open the valve only under certain conditions:
A sensor triggers it
A computer sends a signal
An operator flips a switch

Example:
In an air suspension system, it may open only when height adjustment is needed, then shut to hold pressure.

4. Prevent Leaks or Backflow

It ensures no fluid or gas passes unless it's energized, helping maintain system pressure or cleanliness.

5. Controlled Timing or Automation

In automated systems (industrial or automotive), it’s used for timed or conditional activation of flow.

1. Valve Stuck Open (even without power)

• Flow continues even when the system is OFF.

• In an air system: you may hear constant hissing or feel air moving when it shouldn't.

• In a fan clutch: fan runs constantly, even at idle or cold starts.

2. Valve Stuck Closed (even with power)

• No flow even when it should be open.

• Fan clutch won’t engage, air suspension doesn’t lift, coolant doesn't circulate, etc.

• Can cause overheating or mechanical failure.

3. Intermittent Operation

• Valve works sometimes, fails other times.

• Could be due to:

  • Loose wire

  • Internal coil starting to short

  • Dirty or sticking plunger

4. Electrical Issues

• Blown fuse when valve is energized.

• No voltage at the connector (could also mean bad wiring).

• Coil gets hot to the touch, smells burnt, or shows zero or infinite resistance.

5. Audible Clicking is Missing or Continuous

• Normally, you hear a soft click when the valve opens or closes.

• No sound = might be stuck or electrically dead.

• Rapid clicking = unstable voltage or failing coil.

6. Fluid or Air Leakage

• If the valve isn’t sealing properly, you may see or hear leaks.

• For air valves: constant hissing from the solenoid.

• For fluid valves: drips or weeping around fittings or body.