How to Install the WL601P Low Water Level Probe on Your Coolant Tank

The WL601P is a push-fit water level probe engineered for use with Bolec’s WL601 and WL701 Low Coolant Alarm modules. It detects low coolant conditions in both automotive and industrial systems, providing early warning before engine damage or overheating can occur. Its compression-style mounting system makes it easy to install on both metal and plastic tanks without requiring threaded ports.

Product Overview

• Non-threaded, push-on design for quick installation
• Stainless steel M4 clamp nut compresses seal for leak-proof mounting
• Fits through a standard 9.5 mm (3/8″) hole
• 6.4 mm spade terminal for simple electrical connection
• Ideal for plastic tanks when used with a second WL601P as a ground

Typical Applications

• Radiator low coolant detection (automotive, agricultural, marine)
• Plastic overflow/preserve tank level sensing (with 2-probe setup)
• Auxiliary water level alarms for off-road vehicles or generator sets

Installing WL601P on a Metal Tank

Metal tanks conduct electricity, allowing the tank itself to act as a ground. Only one WL601P probe is required.

Steps:

1. Choose Location: Select a point on the tank wall above the danger zone for coolant loss.
2. Drill Hole: Drill a 9.5 mm (3/8″) hole through the tank wall.
3. Install Probe: Insert the probe and tighten the M4 stainless nut clockwise to compress the rubber seal inside the tank wall, forming a secure, leak-proof fit.
4. Ensure Ground: Confirm the tank has a reliable ground connection to chassis or battery negative.
5. Connect to Alarm: Wire the probe to the WL601 or WL701 alarm module’s sensor input.
6. Test: Simulate a low coolant level and verify the alarm functions correctly.

Installing WL601P on a Plastic Tank

Plastic tanks are non-conductive and require two WL601P probes: one for signal and one for ground reference.

Steps:

1. Select Locations: Position the signal probe at the desired low level and the ground probe lower so it stays submerged under normal conditions.
2. Drill Holes: Use a 9.5 mm (3/8″) drill bit to create two mounting points.
3. Mount Probes: Insert each probe and tighten the clamp nut until the rubber seal compresses to create a leak-proof seal.
4. Wiring: Connect the upper probe to the sensor input and the lower probe to the ground input of the WL601 module.
5. Power Connection: Power the WL601 from a switched 12V or 24V supply with proper fuse protection.
6. Function Test: Reduce coolant level below the signal probe and check that the alarm triggers.

Installation Tips

• Seal Integrity: Ensure probe seals are compressed evenly to prevent leaks.
• Cable Protection: Use conduit or loom to guard wiring from heat, vibration, or abrasion.
• Visibility and Sound: Mount alarm indicators or buzzers where the operator can easily hear or see them.

Conclusion

Whether you’re working with a metal or plastic coolant tank, the WL601P is a fast, reliable way to implement water level monitoring. With just one or two probes and no need for threaded ports, it’s perfect for DIY setups or OEM applications. Follow the above steps to install with confidence and protect your engine from avoidable damage.

Need help choosing the right setup? Contact Bolec Electronics for technical support and compatible accessories.