$42.90
Free delivery · 7–14 days
LED Side Marker Lights for BMW — Sequential Amber FlashBrake Fluid Tester Pen — Instant Moisture Detection
About this itemAll characteristics
Typeautomotive tools & diagnostics
Compatible fluidsDOT3, DOT4 (glycol‑based)
Detection range0–4% moisture by conductivity
Indicators4 moisture LEDs (green/yellow/red) + 4 battery LEDs
Power1× LR44 / A76 1.5V alkaline cell (included)
Probe materialGold‑plated brass pins
From the seller
One quick dip of the gold‑plated probes into your brake fluid reservoir gives you an instant red‑yellow‑green answer.
Read the full descriptionDescription
One quick dip of the gold‑plated probes into your brake fluid reservoir gives you an instant red‑yellow‑green answer.
Instantly test brake fluid moisture content with color-coded LED indicators—prevents costly brake failures
Solves
- unknown brake fluid condition
- moisture contamination detection
- maintenance compliance
- safety diagnostics
Know your brake fluid in seconds—not after a failure
One quick dip reveals moisture contamination in DOT3 or DOT4 brake fluid with a red‑yellow‑green LED. No guesswork, no shop visit—just a clear answer that can save your brakes.
Three things that separate it from guesswork
- Color‑coded certainty
Green means go, red means stop. The simple 4% moisture scale gives you a real‑time readout—no interpretation needed.
- Battery indicator always on display
Four small LEDs show remaining battery life, so you’re never caught with a dead tester before a service check.
- Metal probes and matte body
Gold‑plated pins resist corrosion, and the matte black polymer casing shrugs off workshop grime. A sturdy pen clip keeps it handy.
Numbers that matter when you’re under the hood
- 0–4%Water content in brake fluid
- Green < 2%Safe to drive
- 2–3%Plan a flush soon
- > 3%Immediate service needed
3‑second test, every time
- 1Pop the cap
Locate your brake fluid reservoir under the hood. Unscrew the cap and set it aside on a clean rag.
- 2Dip the probes
Submerge the gold pins fully in the fluid. The tester will immediately light up—no need to wiggle or wait.
- 3Read the light
Green (0–2%) means good. Yellow (2–3%) signals a flush is due soon. Red (3–4%) means your fluid needs immediate attention. Wipe the probes clean and recap the reservoir.
Everything that arrives
- Brake fluid tester pen×1
Pre‑installed battery, ready to use
- Metal probe pins×2
Gold‑plated, non‑removable
From brake fade to confident stops
Why this pen earns its spot
| This tester | Test strips | Cheap plastic pens | |
|---|---|---|---|
| Instant result | — | ||
| Repeatable digital‑style reading | — | Partial | |
| Built‑in battery indicator | — | — | |
| Gold‑plated corrosion‑resistant probes | — | — | |
| Works in low light | — |
Characteristics
Main
Categoryautomotive tools & diagnostics
Details
Compatible fluidsDOT3, DOT4 (glycol‑based)
Detection range0–4% moisture by conductivity
Indicators4 moisture LEDs (green/yellow/red) + 4 battery LEDs
Power1× LR44 / A76 1.5V alkaline cell (included)
Probe materialGold‑plated brass pins
Body materialMatte ABS polymer with metal clip
Dimensions (L×W×H)142 × 19 × 15 mm (pen body)
Weight28 g (with battery)
Reviews
Questions and answers
How accurate is the moisture percentage?
w
Wanelo · seller
It measures electrical conductivity across the probes, which correlates directly to water content. In controlled tests, the scale maps reliably to 0–4% moisture, enough to flag dangerous contamination before brake fade occurs.
Will it work on DOT5 fluid?
w
Wanelo · seller
No. This tester is designed for DOT3 and DOT4 glycol‑based fluids only. DOT5 (silicone‑based) has different electrical properties and will give an incorrect reading.
How often should I test my brake fluid?
w
Wanelo · seller
Many technicians recommend a check at every oil change—about every 5,000–7,500 miles. If you live in a humid climate, test more frequently; moisture absorption accelerates.
The LED scale doesn’t light up—what now?
w
Wanelo · seller
First, check the battery. The four battery indicator LEDs show remaining charge. If none light, replace the 1.5V cell inside. Also ensure the metal probes are clean and fully submerged in fluid.
Is the battery replaceable?
w
Wanelo · seller
Yes. A standard LR44 or A76 button cell is user‑replaceable. The pen cap unscrews to access the compartment.
Why not just use a test strip?
w
Wanelo · seller
Strips can be subjective and require a color chart in good light. This pen gives an instantaneous, repeatable digital‑style reading with bright LEDs you can see even under the hood at night.
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