Brake fluid tester pen with 5 LEDs for DOT 3, 4, 5 and 5.1
Amio brake fluid tester – shows you when your brake fluid needs changing.
A brake fluid tester is a pen-sized, battery-powered gauge that measures how much water your brake fluid has absorbed, using two steel probes dipped straight into the reservoir. Five LEDs give you the reading after one second. It's for drivers who look after their own car or van, and for anyone who wants to check the brake fluid before a long drive.
Brake fluid draws in moisture over time through the porous brake pipes, so it can start forming vapour bubbles below the boiling point printed on the label (source). Those bubbles compress, and the vehicle takes longer to stop. This tester tells you how much water has already built up, so you find out at the reservoir, not when you brake.
At a glance
- What for: water content of your vehicle's brake fluid, checked at the reservoir
- Display: 5 LEDs, from no water up to at least 4%
- Fluid types: DOT 3, DOT 4, DOT 5, DOT 5.1
- Battery: 1 × AAA, not included
- Size: 15 cm long, 2 cm across, with a pocket clip
Key benefits
- You know when to change it: one red LED means about 3% water, and a change is recommended. Two red LEDs mean at least 4%, and the fluid needs changing urgently. While only green and yellow LEDs light up, the fluid is in the "OK" band and you don't replace it for nothing.
- One second in the reservoir: no syringe, no sample, no draining. You dip the probes in and the LEDs already show the result.
- Readable without numbers: green, yellow and red lights tell you the state of the fluid, with the scale printed on the body and the safe band marked "OK".
- One tester for several vehicles: it works with all four DOT types listed, whatever the make or model, so the same pen checks the car, the van and a friend's car.
- Lives in the glovebox: about the size of a chunky pen, with a pocket clip. A cap covers the probes when you're not using it.
- Switches itself off: after 12 seconds without use it powers down, so a forgotten tester doesn't flatten its battery.
New to the Convoy Vibe range. We've been selling to truck drivers since 1991, and a brake fluid check you can do yourself, on the driveway or at a campsite, belongs in that kit.
How to use the brake fluid tester
- Unscrew the cap of the brake fluid reservoir.
- Pull the cap off the tester's probes.
- Press the button on the top to switch it on: the green LED lights up.
- Dip the probes into the fluid up to the plastic rim and hold them there for about one second.
- Read how many LEDs are lit. The tester switches itself off after 12 seconds.
- Rinse the probes under running water and put the cap back on.
What it is not for
It shows the water content in steps. It doesn't measure the boiling point and doesn't give a reading to the decimal. It's made for the DOT fluid types listed above.
What else you need
One AAA battery. It isn't in the box, so have one ready.
What's in the box
- 1 × brake fluid tester pen with a cap over the probes
Technical specifications
| Brand | Amio |
|---|---|
| Model | XHX-008 (part no. 03123) |
| Measures | Water content of brake fluid |
| Fluid types | DOT 3, DOT 4, DOT 5, DOT 5.1 |
| Probes | 2, steel |
| Display | 5 LEDs (1 green, 2 yellow, 2 red) |
| Green | Battery OK, no water |
| Green + 1 yellow | Less than 1% water |
| Green + 2 yellow | About 2% water, normal range |
| Green + 2 yellow + 1 red | About 3% water, change recommended |
| Green + 2 yellow + 2 red | At least 4% water, change urgently |
| Time in the fluid | About 1 second |
| Auto power-off | After 12 seconds of inactivity |
| Power | 1 × AAA battery (not included) |
| Length | 15 cm |
| Diameter | 2 cm |
| Material | Plastic body |
| Colour | Black |
Frequently asked questions
Does it give an accurate reading with silicone-based DOT 5 fluid?
Yes. The Amio brake fluid tester gives a valid reading with DOT 5 as well as with the glycol-based types.
What does it mean when the red LEDs flash?
The battery is flat. Change it too if the green LED doesn't come on when you press the button.
How often should I check my brake fluid?
At the intervals your vehicle's manufacturer specifies, replacing it when needed. With the Amio brake fluid tester you can do that check yourself at the reservoir.
If your vehicle takes one of the DOT fluids listed above, this tester tells you whether the fluid is due for a change.
