Odd periodic squeaking noise when braking

I've searched everywhere and can't find someone who has my problem. I just bought my Tacoma last month, and everything has been great until recently; when braking at slow speeds, I hear this squeak/creak or something( my girlfriend says it sounds like the truck is farting) coming from the rear driver drum brake. The weird thing is it's not a constant squeak, but rather it seems to happen when the wheel turns past a certain point, so as I slow down, the frequency of the squeaking slows down. I thought the shoes might have some debris on them, so yesterday I got in there with some brake cleaner, but that didn't fix it.
When I bought the truck, I was told they did an $800 brake service, so it's pretty annoying that this is happening. I know new brake shoes have a break-in period, but this started like a week ago.
Any ideas on what could cause this is greatly appreciated

 

My guess is noise where the shoe contacts the backing plate. Put a light coat of brake lube in those areas.

 

Pull the drum and do a visual check, make sure assembly is correct.

 

I’d first try to find the noise. Periodic makes that tricky tho. Have someone near the wheel as you brake. Communicate clearly so you don’t run them over.

Common noise causes are glazed contact surfaces, pad wear indicators rubbing the rotors. Glazing can be knocked off with emery cloth on the drums, rotors, shoes. Pads I like to scrub against rough concrete. I’ve done the thing with emery cloth hundreds of times, never had an issue with uneven wear.

 

I’m going to take the wheel off tomorrow and check around thanks for the suggestion

 

So I got in there to lube the contact points on my breaks and now I can’t get on the drum cover and there is air in my breaks. Does anyone know how this could’ve happened?

 

easy enough to bleed, just need a friend to step on the pedal, the bleeder is at the top of the wheel cylinder. To get the cover back on, you may just need to adjust the star in a bit.

 

Somehow my dad managed to get the cover back on after messing with it a bit and the brakes feel fine again.