{"product_id":"brake-fluid-tester-pen-dot3-dot4-dot5-led-moisture-check","title":"Brake Fluid Tester Pen – DOT 3\/4\/5 LED Moisture Checker","description":"\n\u003ch2\u003eKnow When to Change Your Brake Fluid — Before It's Too Late\u003c\/h2\u003e\n\u003cp\u003eYour brakes are your car's most critical safety system, and degraded brake fluid is one of the most overlooked causes of brake failure. This \u003cstrong\u003eDigital Brake Fluid Tester Pen\u003c\/strong\u003e gives you an instant, accurate reading of moisture levels in your brake fluid — no guesswork, no costly shop visits. Compatible with \u003cstrong\u003eDOT 3, DOT 4, and DOT 5\u003c\/strong\u003e brake fluids, it's the essential automotive safety tool for every driver, DIY mechanic, and auto technician.\u003c\/p\u003e\n\n\u003cp\u003eMade in Mainland China.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Moisture in Brake Fluid Is Dangerous\u003c\/h3\u003e\n\u003cp\u003eBrake fluid is hygroscopic — it naturally absorbs moisture from the air over time. As water content increases, the fluid's boiling point drops significantly. This can cause \u003cstrong\u003ebrake fade, spongy pedal feel, and even complete brake failure\u003c\/strong\u003e during hard stops. Experts recommend checking and replacing brake fluid regularly to maintain peak stopping performance. Learn more about vehicle braking safety from the National Highway Traffic Safety Administration, or read about automotive fluid maintenance at CPSC.gov.\u003c\/p\u003e\n\n\u003ch3\u003e5-LED Colour-Coded Display — Results in Seconds\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🟢 Green only (H₂O \u0026lt;1%):\u003c\/strong\u003e Brake fluid is in excellent condition — no action needed.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🟢🟡 Green + Yellow (H₂O ~1%):\u003c\/strong\u003e Good condition — continue to monitor.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🟢🟡🟡 Green + 2× Yellow (H₂O ~2%):\u003c\/strong\u003e Acceptable — plan to replace within 6 months.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🟢🟡🟡🔴 Green + 2× Yellow + Red (H₂O ~3%):\u003c\/strong\u003e Replacement recommended soon.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🟢🟡🟡🔴🔴 All 5 LEDs (H₂O ≥4%):\u003c\/strong\u003e \u003cem\u003eReplace brake fluid immediately\u003c\/em\u003e — continued use is dangerous.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e🔴 Flashing Red:\u003c\/strong\u003e Battery low — time to replace the AAA battery.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e✅ Tests \u003cstrong\u003eDOT 3, DOT 4 \u0026amp; DOT 5\u003c\/strong\u003e brake fluids\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003e5-LED display\u003c\/strong\u003e for clear, colour-coded moisture readings\u003c\/li\u003e\n  \u003cli\u003e✅ Measures conductivity change for accurate water content detection\u003c\/li\u003e\n  \u003cli\u003e✅ \u003cstrong\u003eAuto power-off\u003c\/strong\u003e to conserve battery life\u003c\/li\u003e\n  \u003cli\u003e✅ One-button operation — press to power on, dip probe, read result\u003c\/li\u003e\n  \u003cli\u003e✅ Compact pen-style design fits in your glovebox, toolbox, or garage\u003c\/li\u003e\n  \u003cli\u003e✅ CE certified\u003c\/li\u003e\n  \u003cli\u003e✅ Lightweight at just 50g\u003c\/li\u003e\n  \u003cli\u003e✅ Requires 1× LR03 AAA battery (not included)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow to Use\u003c\/h3\u003e\n\u003col\u003e\n  \u003cli\u003ePress the button to power on — the green LED will illuminate.\u003c\/li\u003e\n  \u003cli\u003eInsert the probe tip into your brake fluid reservoir for about 1 second.\u003c\/li\u003e\n  \u003cli\u003eRead the LED display to instantly see your brake fluid's moisture level.\u003c\/li\u003e\n  \u003cli\u003eThe unit will automatically power off after use to save battery.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003ePackage Contents\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1× Brake Fluid Tester Pen (battery not included)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eYou May Also Like\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003ca href=\"\/products\/100-pack-disposable-nitrile-gloves-latex-free-white-oil-proof\"\u003e100-Pack Disposable Nitrile Gloves – Latex-Free, Oil-Proof\u003c\/a\u003e — protect your hands when working with brake fluid\u003c\/li\u003e\n  \u003cli\u003e\n\u003ca href=\"\/products\/120ml-heavy-duty-metal-rust-remover-anti-rust-coating-spray\"\u003e120ml Heavy-Duty Metal Rust Remover \u0026amp; Anti-Rust Spray\u003c\/a\u003e — keep your vehicle's components in top shape\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eLearn more: \u003ca href=\"https:\/\/en.wikipedia.org\/wiki\/On-board_diagnostics\" target=\"_blank\" rel=\"noopener\"\u003eOn-board diagnostics\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What brake fluid types does this brake fluid tester pen support?\u003c\/h4\u003e\n\u003cp\u003eA: This brake fluid tester is compatible with \u003cstrong\u003eDOT 3, DOT 4, and DOT 5\u003c\/strong\u003e brake fluids, making it suitable for the vast majority of passenger cars, trucks, motorcycles, and other vehicles.\u003c\/p\u003e\n\n\u003ch4\u003eQ: How accurate is the brake fluid moisture tester?\u003c\/h4\u003e\n\u003cp\u003eA: The tester detects changes in the electrical conductivity of brake fluid caused by water absorption, providing reliable moisture level readings across five LED stages — from less than 1% water content up to 4% or more. It gives a fast, practical indication of whether your brake fluid needs to be replaced.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Does the brake fluid tester pen come with a battery?\u003c\/h4\u003e\n\u003cp\u003eA: No, a battery is not included. The tester requires one standard LR03 (AAA) battery, which is widely available. When the red LED flashes, it's time to replace the battery.\u003c\/p\u003e\n\n\u003ch4\u003eQ: How often should I check my brake fluid with this tool?\u003c\/h4\u003e\n\u003cp\u003eA: It's good practice to check your brake fluid at least every 6–12 months, or whenever you notice a spongy brake pedal, reduced braking performance, or before long road trips. Regular checks help you stay ahead of potential brake safety issues.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What brake fluid types does this brake fluid tester pen support?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This brake fluid tester is compatible with DOT 3, DOT 4, and DOT 5 brake fluids, making it suitable for the vast majority of passenger cars, trucks, motorcycles, and other vehicles.\"}}, {\"@type\": \"Question\", \"name\": \"How accurate is the brake fluid moisture tester?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The tester detects changes in the electrical conductivity of brake fluid caused by water absorption, providing reliable moisture level readings across five LED stages — from less than 1% water content up to 4% or more. It gives a fast, practical indication of whether your brake fluid needs to be replaced.\"}}, {\"@type\": \"Question\", \"name\": \"Does the brake fluid tester pen come with a battery?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"No, a battery is not included. The tester requires one standard LR03 (AAA) battery, which is widely available. When the red LED flashes, it's time to replace the battery.\"}}, {\"@type\": \"Question\", \"name\": \"How often should I check my brake fluid with this tool?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"It's good practice to check your brake fluid at least every 6–12 months, or whenever you notice a spongy brake pedal, reduced braking performance, or before long road trips. Regular checks help you stay ahead of potential brake safety issues.\"}}]}\u003c\/script\u003e","brand":"Oasis Select","offers":[{"title":"Default Title","offer_id":47710907531369,"sku":"\u003cnone\u003e","price":7.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0679\/7931\/3257\/files\/Sb2ef872ac0dd4cd18f9590ca4e45385eU.webp?v=1782062827","url":"https:\/\/oasis-select.com\/products\/brake-fluid-tester-pen-dot3-dot4-dot5-led-moisture-check","provider":"Oasis Select","version":"1.0","type":"link"}