Possible Actuator issue.

Recently my 2008 Prius (187,000 miles) actuator started going off constantly. It got even worse after I changed my brakes. Now theres this weird knocking noise seemingly right in the middle underside of the car, or, well its hard to tell. Seems like the right side when im sitting inside the car, but in the middle when im outside.

Not sure how safe it is as I drive for a living, but im too broke to even get it checked atm. I do wonder if some leak from the lines is engaging the actuator. The actuator is on every 10-20 seconds. The knocking noise itself only happens when the cars parked and only when the actuator is going off. Surely they must both be related to go off at the same time, every single time. I cant find what the hell it would be, no real guides or info on it. Found one guy on here with the same sound, but it seems there was no solving it.

You lads have any ideas? I can post video if its needed. Well, apparently my video file isn't compatible from my phone.