One-Person Brake Fluid Exchange with Automatic Low-Fluid Stop
The AST603 feeds fresh fluid into the reservoir under pressure while used fluid drains at one caliper at a time, so nobody has to pump the brake pedal. It stops on its own when the fresh-fluid bottle runs dry or pressure cannot build.
- One-Person Operation
- 0.5–2.5 bar
- 1.6 L/min
- One Caliper at a Time
- Low-Fluid Auto Stop
Key Features
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One-Button Pulsating Exchange
After the bottle, hoses and reservoir connection are prepared, one button starts the automatic exchange. Two sub-pumps work together to deliver fresh fluid at the set pressure while used fluid is released at each caliper in the prescribed sequence.
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Fluid-Level Monitoring
If the fresh-fluid container runs out during filling, the machine stops to help keep air out of the brake lines.
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Pressure Monitoring
The machine also stops if pressure cannot be generated or the pump draws in air.
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Practical Control Layout
Pressure gauge, pressure adjustment knob, indicator light, metal hose fittings, aviation power plug, safety device and a screw-column quick connector.
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Corrosion-Resistant Hoses
Flexible hoses made for prolonged contact with brake fluid and other service chemicals.
Model Comparison
| AST603 | AST605 | AST609 | |
|---|---|---|---|
| Calipers serviced at once | 1 | 1 | 2 |
| Reservoir adapters included | 1 | 3 | 7 |
| Working pressure | 0.5–2.5 bar | 0.7–3 bar (±0.2 bar) | 0.5–2.5 bar |
| Fluid bottles | 1 L used-fluid bottle | 1 L used-fluid bottle | 1.5 L used-fluid + 1 L fresh-fluid bottle |
| Weight | 5.2 kg | 5.3 kg | 7.4 kg |
What’s in the Box
- AST603 brake fluid exchanger
- Aviation-plug power cable
- Filling hose
- Used brake fluid bottle
- Default reservoir adapter
- User manual

How to Use
- Prime the machineBefore first use, bleed the machine so its internal line is filled with brake fluid; fill the vehicle reservoir to the maximum mark.
- Connect the adapterFit a matching adapter to the brake fluid reservoir and check the cap and hose connections for leaks.
- Build initial pressurePress and hold the start button for 5–6 seconds; release once pressure is above 0.6 bar.
- Set working pressureAdjust the working pressure; the operating guide usually recommends about 2 bar.
- Open the bleed screwLoosen the bleed screw on the wheel cylinder or caliper to drain the old fluid.
- Watch the drain bottleCheck the layering and color in the used-fluid bottle; the darker layer is the old fluid.
- Close, then switch offTighten the bleed screw first and only then turn the machine off, so air cannot enter the system.
Full procedure and troubleshooting: AST603 user manual (PDF).
Good to Know
Caution
- Keep watching the fresh-fluid bottle. If it empties and the machine keeps running, air may enter the brake system.
- On vehicles with an electronic power brake pump, use the AST603 together with a diagnostic computer.
- Brake fluid is toxic. Wear safety goggles and protective gloves; wash any skin contact with water immediately and remove contaminated clothing.
- The single default adapter does not fit every reservoir; check the opening before service.
Care
- Unplug the power cable before working on the machine, and do not open or modify it.
- Inspect the machine before each use; stop if anything is abnormal and have it repaired professionally.
- Keep the machine dry and do not operate it in damp conditions.





































