Usually after it rains, my back drum brakes lock up when i'm only going a couple miles an hour. Does this mean that moisture is getting inside of them? If it does, can the moisture ruin the brakes?

 

moisture will only just increase your braking distance, the shield is only there for to help protect the shoes from any debris entering the drum assembly.. i would assume at a low low speed for the wheels to lock up either your applying the brakes waaay too much or theres a problem with the master cylinder or brake booster or did you just put new shoes and drums on it?

 

they do that, it's just the way things are,
what it is is that the brakes catch because of the water, there's no easy way around it
every vehicle i've driven with drum brakes does that, from tractors to golf carts,
just apply light pressure, before you start slowing down, so the pads expel the water, then they should work fine after that.
mine do it too,
the ford at work does it with even a heavy dew

 

It was doin that to me the other day actually. All I did was when I was slowing at a stop sign...I would just press on the brakes really hard, and then after that the brakes were all good for the day wiith slowing at stop signs.

 

never noticed that myself unless it does happen and im unaware of it.. i know my fronts lock up with hard enough braking

 

We didnt do any brake work on it since we got the truck. But i think its going to need some brake work because the front right brake squeeks and i dont know the shape of the shoes in the back. And for when they lock up, i press the brake pedal down a little bit and they lock up. I dont have to press them down real hard for them to lock up, they just do when i press them down a little bit.

 

Is it all the time? You could have a leaking wheel cylinder or have contaminated your shoes with a petroleum product. That will cause your brakes to lock up with only a tap.

 

+1 exactly ^^^^ that or a shot shoe...

 

It only does it when it after it rains or when its really damp outside. Then after i drive it for a bit, they don lock up.

 

yea does it make a major squeak too? Yea when you stop at a stop sign...just push on the brake really hard as the truck almost stops. Worked for me.