non-constant squeaking when braking

[mmhendrie]

Folks - looking for some advice. I'm getting some non-constant squeaking when braking. What I mean by that is, it's not the constant squeal sound when I apply the breaks that I would associate with the low brake indicator - the sound is rhythmic, I only notice it at lower speeds, and it seems the rhythm of the noise depends on how fast I'm going - meaning, if i'm braking at a slightly quicker speed, the squeaking is fast, at a lower speed, it's slow. The stopping power of the car itself is just fine. The sound seems to be coming from the back (rear wheels) - I can't be 100% certain, but that's my feeling. The sound itself sounds like a rusty spring bouncing up and down, or perhaps like a squeaky door, again, non-constant, on-off-on-off until the car comes to a stop. Not very loud, but noticeable.

A bit of background: 2004 PT Cruiser LTD 70k miles - with front disc, and rear drums. The front discs have about 15k miles on them and look great, the rear drums about 12k miles. Note, and I embarrassingly add this detail knowing it might indicate the cause of the issue - I'm the one who changed both front and rear brakes. My confidence level on the front is very high - I've done them a few times, and even changed the rotors last time round. The rear, I struggled with, as it was my first time. I did get the drum machined etc. - followed what I'd researched to be good practices, but, perhaps I mis-stepped somewhere? Anyhow, any advice, as always, greatly appreciated!

[dsab]

I can't think of anything that would cause a squeaking sound when breaking. If it was a rubbing/grinding sound I would consider the possibility one of the break shoe retainers or brake springs had come loose. The problem only started after you replaced the rear brakes?

[mmhendrie]

I really can't be sure if it was there as soon as I replaced by rear drums, but it certainly wasn't there before I replaced them.

[rob302]

Did you apply brake grease to the bump outs on the drum brake backing plate?

[mmhendrie]

I can't be sure on that - just because it was a while back now. I'll pull the drums, what/where exactly should I be looking for that? I have some anti-squeal grease, so if you can point me in the right direction, i'll throw some on there. While I have the drum off, anything else I should look for/check for that might be the cause?
thanks!
Matt

[rob302]

where to grease drum brakes - Google Search

Click this and look at the images. You'll get the idea. I'm only on a phone right now, so it's hard to pick a good pic