Slight grinding or rubbing sound when braking

I have an 08 Toyota Sienna and yesterday I started to notice a very slight grinding or rubbing sound when I apply the brakes coming from the passenger side front wheel. I can only hear the grinding or rubbing sound when I am going very slowly (like the last 20 feet when approaching a stop sign). The sound pulses slightly like two surfaces that are not parrell are rubbing. There is no pulsation or wobble felt in the brake pedal. Any suggestions? I’m thinking it’s time to get the rotors turned, but it could also be the brake pads.

I’m thinking you should pull ALL the wheels and carefully inspect the condition of the brakes…Many shops will do this for free, hoping you will use them to repair the brakes if needed or when needed…This is not something to put off. If the brakes are worn out, every stop is grinding away expensive parts…

Well, if you’re turning the rotors, you have to replace the pads.
Clearly you know enough about cars to think the rotors need turning - How do the pads look?

It is not serious as brake issues go. If you like things quiet and smooth thats fine. I would suggest a bit of lube on the caliper shoe slide and maybe replacement pads with anti squeal. The pulsation may not be a bad rotor since you do not notice it at higher speeds.

08 Sienna has throwaway rotors. Don’t bother turning them or you will end up with warped rotors in short order. You can pick up good quality rotors for about 50 bucks a piece and good pads for about 50 bucks. If you are reasonable handy and have the tools replacing front pads and rotors on a Sienna should take you less than 90 minutes, even if you are meticulous about cleaning and lubing (as I am). Parts should be about $150 plus brake cleaner and silicone lube. One other trick I use on my Toyotas is to put some “Disc Brake Quiet” on the back of the pads, even if they have shims. It is goopy, rubbery stuff that keeps your pads from squealing. It peels off like dried caulk at the next brake job and I NEVER have noisy brakes.

For what it’s worth, I buy all of my rotors and pads from Amazon now. As long as you are sure of your part numbers it is the best thing ever for brake parts (and wiper blades).