The short answer
Bleed the brakes the normal way first. Then connect the tool, go into ABS and choose the bleed function (sometimes called "fill and bleed" or "bleeding"). The tool runs the pump and valves in turn while you press the pedal and open the bleed nipples in the order it tells you. Top up the reservoir between cycles and finish with a normal bleed.
For most brake fluid changes you don't need it. But if you have replaced the hydraulic unit, the reservoir ran dry, or the pedal still feels spongy after bleeding as usual, it is because air is trapped inside the ABS unit. Only the tool can get it out.
When you need to bleed with a tool
- You have replaced the ABS hydraulic unit or control unit.
- The fluid reservoir ran dry during the job and air got into the circuit.
- You have replaced the master cylinder or a brake hose and the pedal won't firm up.
- The manufacturer specifies it for a brake fluid change (some models with stability control always require it).
If you are only changing pads, or doing a routine fluid change and the reservoir never ran dry, a normal bleed is usually enough.
What you need
- Brake fluid of the type your car requires (check the reservoir cap or the handbook). Fresh, from a newly opened bottle.
- A spanner for the bleed nipples, clear tubing and a catch bottle.
- A second person to press the pedal, or a pressure bleeder.
- A charger or battery support unit: the process is long and the pump draws current.
- A diagnostic tool with the ABS bleed function for your car.
Step by step
- Bleed the brakes the normal way, wheel by wheel, in the manufacturer's order. That clears the air from the hoses and callipers.
- Fill the reservoir to the maximum mark and leave the cap on but not tightened.
- Connect the tool, turn the ignition on with the engine off and identify the car.
- Go into ABS or ESP and find the bleed function in the special functions or service menu.
- Follow the on-screen instructions. Typically it will ask you to press the pedal several times, open a specific bleed nipple and keep it open while the pump runs for a few seconds. Then close it and move on to the next wheel.
- Top up the reservoir between cycles. Never let it drop below the minimum or you will let air back in.
- Finish with another normal bleed if the tool or the manufacturer says so.
- Read and clear the ABS faults. It is normal for one or two to be left over from the process. Check the warning light goes out.
- Test the pedal with the engine running: firm, with no long travel. Then a low-speed test somewhere safe.
Safety. If the pedal is still soft when you have finished, don't take the car on the road. Repeat the process or take it to a garage. Brake fluid damages paint: wipe up any drips with water straight away.
Common mistakes
- Letting the reservoir run dry halfway through. It is the most common reason for having to start again.
- Not following the wheel order the tool gives you. Every manufacturer has its own.
- Using old fluid or the wrong type. Brake fluid absorbs moisture once the bottle is open.
- Low battery. The pump draws current and the control unit may abort the process.
Which iCarsoft tools have ABS bleeding
It is on the current multi-brand range (CR Pro, CR Pro+, CR Max, CR Max P and CR Ultra) and the V2.0 single-brand tools, such as the VAWS V2.0, BMM V2.0, MB V2.0 and FR V2.0. The V1.0 range does not include it. As it depends on each make and model, check on each tool's product page that your car is covered before you buy.
If you are changing the rear pads on the same job and your car has an electronic parking brake, here is how to open the EPB callipers.
