AUTOOL AS501 Digital Brake Fluid Tester
US$23.99
Key features
- Select DOT 3, DOT 4, DOT 5, DOT 5.1, ENV 4, or ENV 6 before testing.
- Complete a test cycle in about 10 seconds and view water-content and fluid-grade results.
- Reach confined reservoir openings while keeping the handheld display visible.
- Read the selected fluid mode and completed result in bright or dim service areas.
- Run the tester from two 1.5 V AA batteries without connecting to the vehicle.
- Six Brake-Fluid Modes: Select DOT 3, DOT 4, DOT 5, DOT 5.1, ENV 4, or ENV 6 before testing.
- About 10 Seconds: Complete a test cycle in about 10 seconds and view water-content and fluid-grade results.
- 260 mm Flexible Probe: Reach confined reservoir openings while keeping the handheld display visible.
- 1.8-Inch Backlit Display: Read the selected fluid mode and completed result in bright or dim service areas.
- Portable AA Power: Run the tester from two 1.5 V AA batteries without connecting to the vehicle.
- 3-Year Warranty Main unit 3 years · Accessories 1 year
- 90-Day Returns Eligible returns within 90 days
- Official Store Genuine products · Direct support
AUTOOL AS501 · Six-Mode Brake Fluid Tester
Reach Tight Reservoirs for Fluid Checks
Screen brake-fluid water content after selecting the matching DOT or ENV mode. AS501 reaches confined reservoirs with a 260 mm flexible probe and returns water-content and fluid-grade guidance in about 10 seconds. The 1.8-inch backlit display keeps the selected fluid mode and completed result visible during service.
- DOT 3 / 4 / 5 / 5.1 / ENV Modes
- About 10-Second Water Screen
- 260 mm Flexible Probe
- 1.8-Inch Backlit Display
- 2 × AA Battery Power
Key Features
Six-Mode Brake Fluid Moisture Tester with a Flexible Probe
Six Fluid Modes
Select DOT 3, DOT 4, DOT 5, DOT 5.1, ENV 4 or ENV 6 before testing so the result uses the intended fluid setting.
10-Second Test Cycle
The tester completes a brake fluid water test in about 10 seconds and displays water content and fluid grade.
1.8-Inch Backlit Display
The backlit screen keeps the selected mode and result readable in bright or dim service areas.
260 mm Flexible Probe
The flexible gooseneck helps reach reservoir openings while keeping the handheld display visible.
Portable AA Power
Two 1.5 V AA batteries power the tester without a vehicle connection.
3 Years Warranty Support
Main unit: 3-year warranty. Standard accessories: 1-year warranty. Warranty Policy.
Service Workflow
Select, Immerse, Read and Clean
Step 1
Confirm the Fluid
Identify the exact fluid family and select the matching mode or calibration.
Step 2
Prepare the Probe
Power the tester as specified and clean the probe so residue from another fluid cannot affect the sample.
Step 3
Take the Reading
Immerse or apply the probe as directed and keep it stable until the result is complete.
Step 4
Interpret the Result
Compare the displayed water-content percentage and fluid grade with the applicable service information.
Step 5
Clean and Store
Remove the probe, clean it promptly with the approved method, and store the tester dry.
Safe Use
Match the Fluid Before Every Test
Fluid Selection and Probe Care
Select the exact brake-fluid mode, clean the probe between samples and use the displayed moisture/grade value for quick fluid screening. It is not a standardized wet boiling-point result.
Specifications
Fluid Modes and Tester Specifications
| Supported fluids | DOT 3, DOT 4, DOT 5, DOT 5.1, ENV 4, ENV 6 |
|---|---|
| Power supply | 2 × 1.5 V AA batteries |
| Operating temperature | -10°C to 50°C |
| Storage temperature | -20°C to 60°C |
| Probe length | 260 mm |
Compare Models
Compare Fluid Testing Methods
Compare models
Choose one or more models. AS501 Brake Fluid Tester is selected by default.
| Product name | ModelAS501 Brake Fluid Tester | ModelAS502 Brake Fluid Tester | ModelAS503 Engine Oil Quality Tester | ModelAS505 Transmission Fluid Tester | ModelAS506 Brake Fluid Boiling Point Tester | ModelAS507 Power Steering Fluid Tester | ModelAS509 Coolant Boiling Point Tester |
|---|---|---|---|---|---|---|---|
| Test Method & Application | |||||||
| Detection Technology | Not stated | Water-content screening; no hydraulic pressure generation or measurement | Optical Probe Technology | Optical Probe Technology | Sample Heating Technology | Optical Probe Technology | Sample Heating Technology |
| Operating Principle | Brake Fluid (Water Content) | Brake Fluid (Water Content) | Engine Oil (Transmittance) | Transmission Fluid(Transmittance) | Brake Fluid (Boiling Point) | Steering Fluid (Transmittance) | Coolant |
| Test Mode Selection | Normal Mode | Normal Mode/Expert Mode | Gasoline Engine/Diesel Engine | Automotive Transmission Fluid | Normal Mode/Brand Mode | Automotive Steering Gear | Normal Mode/Brand Mode |
| Boiling Point Reference Value | ×Not included | ×Not included | ×Not included | ×Not included | ✓Included | ×Not included | ✓Included |
| Normal Mode | 6 Types ENV-4、ENV-6 DOT3、DOT4、DOT5、DOT5.1 | 3 Types DOT3、DOT4、DOT5.1 | ×Not included | ×Not included | DOT3, DOT4 and DOT5.1 (procedure-confirmed selections) | ×Not included | 23 Coolant Brands For ACDELCO、BASF、BOSCH、CASTROL、ENGINE_ICE、EVANS、FORD、HONDA、JOHN_DEERE、KUNLUN、MOBIL、MOPAR、NISSAN、OMTECH、PEAK、PRESTONE、RECOCHEM、SHELL、SKI-DOO、ZEREX、STAR_BRITE、TOTAL、TOYOTA |
| Measurement & Response | |||||||
| Temperature Unit Switching | ×Not included | ×Not included | ℃/℉ | ℃/℉ | ℃/℉ | ℃/℉ | ℃/℉ |
| Temperature Measurement Range | ×Not included | ×Not included | 0-85℃ 0-185℉ | 0-85℃ 0-185℉ | 0-320℃ 0-608℉ | 0-85℃ 0-185℉ | Diluted Coolant Boiling Point Range： 100°C~120°C(212°F~248°F) Original Manufacturer Coolant Boiling Point Reference Range 106°C~191°C(221°F~376°F) |
| Test Duration | 10s Response | 10s Response | 10s Response | 10s Response | 16s Response | 10s Response | 20~40s Response |
| Display, Probe & Power | |||||||
| Backlit Display Screen | 1.8-inch | 2.8-inch | 2.8-inch | 2.8-inch | 1.54-inch | 2.8-inch | 1.6-inch |
| Test Cable Length | 26cm | 26cm | 80cm | 80cm | 4cm | 80cm | 130cm |
| Power Supply Voltage | 3V | 6V | 6V | 6V | 12V | 6V | 10-14V |
| Hose Material | Iron Oxide | 304 Stainless Steel | Teflon | Teflon | ×Not included | Teflon | ×Not included |
| Product Details | |||||||
| Detected Condition / Result | Water content and fluid grade | Not stated | Not stated | Not stated | Not stated | Not stated | Not stated |
Manual & Support
Find the Manual and Fluid-Test Guidance
AUTOOL AS501 User Manual
Open the PDF manual for AUTOOL AS501 fluid mode selection, flexible-probe testing, result interpretation, battery setup, probe cleaning, safe handling and troubleshooting support.
Package Contents
See What Comes in the Box
- Package ContentsAUTOOL AS501 tester, retail packaging and the accessories shown for the current sales package; confirm the selected regional package before ordering.
Buyer Questions
Fluid Fit, Method and Result Questions
Which brake fluids can AS501 test?
Select the matching mode for DOT 3, DOT 4, DOT 5, DOT 5.1, ENV 4 or ENV 6 before placing the clean probe in the fluid.
How long does a test take?
The manufacturer's procedure states that the result appears after about 10 seconds.
Does the reading replace a boiling-point test?
No. AS501 screens moisture/grade through its supported method; follow the vehicle or fluid maker's service procedure when a boiling-point test or another confirmation is required.
How should the probe be handled between tests?
Clean the probe after each sample and avoid transferring residue between different fluid types.
Customer reviews 7
The test is very accurate—really good!
This AUTOOL AS501 brake fluid tester is super handy for home car maintenance. The 260 mm flexible gooseneck probe easily reaches tight brake‑fluid reservoirs. It takes only around 10 seconds to get moisture and fluid‑grade results. The backlit screen works great in dim garages. It supports six modes including DOT3, DOT4, DOT5.1 and ENV series. No vehicle power required, just AA batteries. Now I can check brake fluid condition by myself instead of blindly taking shop suggestions. Good value for money.
The test results are very accurate.
