Brake Fluid Tester – LED Indicator Pen for DOT3 / DOT4 / DOT5

Your Brakes Deserve More Than a Guess

Brake fluid absorbs moisture over time — and when water content gets too high, your braking performance drops and your safety is at risk. This brake fluid tester gives you an instant, accurate reading of your fluid's moisture content in seconds, with a clear 5-LED color display that tells you exactly what action to take.

5-LED Color Scale — Instant Results

No guesswork, no lab required. Dip the probe into your brake fluid reservoir and the 5-LED indicator lights up within seconds to show the exact moisture level in your fluid. Compatible with DOT3, DOT4, and DOT5 brake fluids.

• 🟢 Green only — H₂O <1%: Brake fluid is in excellent condition.
• 🟢🟡 Green + Yellow — H₂O ~1%: Good condition, continue normal use.
• 🟢🟡🟡 Green + 2× Yellow — H₂O ~2%: Acceptable, monitor and retest soon.
• 🟢🟡🟡🔴 Green + 2× Yellow + Red — H₂O ~3%: Replacement recommended.
• 🟢🟡🟡🔴🔴 All 5 LEDs — H₂O ≥4%: Replace immediately — dangerous to continue use.

How to Use

1. Press the button to power on — a green LED should light up. If not, replace the battery.
2. Unscrew the brake fluid reservoir cap.
3. Remove the tester cap and dip the probes into the brake fluid.
4. Read the LED result within seconds.
5. Replace the reservoir cap tightly after testing.
6. The tester powers off automatically after 12 seconds of inactivity.

Simple. Fast. Essential.

Brake fluid testing is one of the most overlooked aspects of vehicle maintenance — yet one of the most critical for safety. This brake fluid tester makes it a 10-second job anyone can do at home, without specialist equipment or a workshop visit. Test every 6 months and know your brakes are ready when you need them.

Technical Specifications

• Type: Brake fluid tester pen
• Compatible fluids: DOT3, DOT4, DOT5
• Indicator: 5-LED color scale (Green / Yellow / Red)
• Material: Plastic
• Auto power-off: 12 seconds
• Power supply: Battery (not included)
• Package includes: 1× Brake Fluid Tester

Test it. Know it. Drive safe. Your brakes are only as good as your fluid.