Grinding noise when releasing/pressing brakes

Check the rear brake pads

 

I'm not sure any gen 2 cars had rear brake pads. Rear drums were used in the US, and I assume Canada also.

In the video, I can make out two noises. The little joy-buzzer or rattlesnake noise at the start of the clip is the sound of the brake pump replenishing the fluid pressure. That's what it's supposed to sound like, and it runs every so often to keep the pressure up. It is a normal sound as long as it happens roughly every few times you brake, and when you open the driver door after not driving for a while. If it runs super often, or repeatedly even when you are not touching the brake, then something is worn out.

The other sound I make out is the sort of quacking / barking / clucking noise while you are holding the brake. That is brake fluid passing through small valves in the actuator that either admit or release small amounts of fluid to hold a certain brake line pressure according to how hard you are pressing the pedal.

Sometimes if there are bubbles in the fluid, it can squirt extra fast through those valves and make that noise, in which case a bleed procedure to eliminate the bubbles can reduce the noise. It may just mean some valves in the actuator are getting old and worn.

You mention varying the pressure of your foot on the pedal. Does the quacking continue if you hold the pressure steady, or only quack when you vary the pressure?

In some cars, the quacking will continue while just holding a steady pressure, which will mean some internal valve is not sealing fully and the brake fluid pressure bleeds off, causing the ECU to repeatedly pulse the corresponding admit-fluid valve to keep the pressure at target, and that makes the repeated quack.

I did not make out a clicking noise in the video, so I'm not sure what to say about that.