When braking, brakes are not working properly

Hi, I'm Dan.

Is the car coming to a stop and then just before the stop do you feel the ABS activate? Feels like the brake pedal fades a little for just a short 1-2 seconds?

If so it sounds like the ABS sensor is losing its signal and activating the ABS procedure. Do you have any ABS codes?

A common problem on your van is that the rust starts to build up under the mounting tab for the ABS sensors on the front wheels. In order to check and correct it you have to remove the front brake rotor, remove the sensor, and clean the mounting area where the sensor goes with a wire brush or sandpaper.
I've attached a picture that shows the sensor location.

This shows how to replace the sensor:

https://www.2carpros.com/articles/how-to-replace-an-abs-wheel-speed-sensor

This shows testing the sensor:

https://www.2carpros.com/articles/abs-wheel-speed-sensor-test