Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.
What can happen is if the drivers front wheel speed sensor is sending a false signal on the wheel speed for that wheel this causes the anti lock system to engage and release this brake as it thinks this wheel is in a skid situation.
For example lets say your slowing hard from like 20 MPH.The other 3 wheel speed sensors are sending a signal of 20 MPH and down as you slow down but shows this signal evenly to the abs computer.The drivers front is going from 20 MPH to 0 MPH instantly so the computer thinks that wheel is skidding and in return it releases the brake to try and take it out of the skid and then re applies it.
What should be done is to have a compatible scan tool plugged into your vehicle to have the codes read out of the abs computer.The scan tool is also used to monitor the wheel speed sensor signal while this is occuring when stopping to see if the sensor is sending a false signal needing replaced.
Usually the master cylinder and brake booster will not cause this fault with only one brake acting up.It would have caused issues with either both front or both rear brakes or all brakes acting up.This sounds more like a faulty wheel speed sensor on the drivers front side.
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