Check ATF Clarity and Temperature Before Deciding on Service
The AS505 dips an optical probe into transmission fluid and shows its transmittance, fluid temperature and a clear status prompt on one backlit screen. Treat the reading as a screening reference alongside the vehicle condition, not as a stand-alone replacement decision.
- ATF Transmittance + Temperature
- 800 mm Flexible Probe
- OK / Warning / Replace Prompts
- 2.8-Inch Backlit LCD
- 4 × AAA Battery Power
Key Features
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Optical Transmittance Probe
An integrated photoelectric transceiver sensor gives stable feedback on fluid clarity. Reduced transmittance may point to impurities, deposits or metal contamination.
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Flexible Teflon Hose
Reaches service points easily and resists oil, oxidation and corrosion.
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Fluid Temperature Readout
A built-in sensor shows the current fluid temperature, switchable between °C and °F.
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Clear Result Indicators
OK for 100–50% transmittance, Warning for 50–30%, and Suggested Replacement below 30%, plus an analog bar graph.
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Readable in Any Light
The backlit LCD stays legible in daylight, dim workshop corners or at night.
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One-Hand Operation
A silicone-lined grip and light body make single-handed testing comfortable.
What’s in the Box
- AS505 transmission fluid tester with integrated 800 mm probe
- User manual
- Retail box

How to Use
- Power onInstall four 1.5 V AAA batteries with correct polarity, then hold the power key for more than 2 seconds.
- Wipe the probeClean the probe tip so old oil or dirt does not affect the reading.
- Check the temperatureMake sure the engine is below 60 °C; switch between °C and °F if needed.
- Submerge the probePlace the probe in the transmission fluid and keep it properly immersed.
- Test and readPress the test button and read transmittance and fluid temperature on the display.
Display, results and troubleshooting: AS505 user manual (PDF).
Good to Know
Caution
- Test only when the engine temperature is below 60 °C.
- Batteries are not listed in the package; prepare four 1.5 V AAA batteries.
Care
- Wipe the probe clean before every measurement.
- A check every 5,000–10,000 km is recommended before deciding on transmission fluid service.
- For viscosity, wear metals or remaining service life, use the specified laboratory tests.
FAQ
Does the AS505 exchange or flush transmission fluid?
No. It only tests fluid transmittance and temperature; it does not drain, flush or refill.
Can it test engine oil, brake fluid or power steering fluid?
It is designed for transmission fluid. Use the AS503 for engine oil, the AS501 or AS502 for brake fluid water content, the AS506 for brake fluid boiling point and the AS507 for power steering fluid.





































