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Rear Brakes lock up before the fronts Do

8K views 14 replies 14 participants last post by  red91z24 
#1 ·
Hey I recently noticed on my 2000 Z24 that my rear brakes started to brake first before my fronts do so i replaced the rear brakes shoes, springs and drums and they still brake before the fronts do. But its mostly when I first use them in the morning then their fine. Any help as to what the cause might be would be great.
 
#4 ·
the brakes are self-adjusting, adjust them to wherever you want with that little wheel-thing, they'll go where they're suppose to as soon as you hit the brakes...

my guess is that ur drums are out of round
 
#5 ·
jack up the rear axle and see if you have any trouble removing the drums. I had an issue with mine where my rear brakes would lock up too. It ended up being the drums. After 200,000 miles, the brakes wore a lip into the drums. THe brakes would adjust into this groove and when you tried to remove the drums, they would get caught and would be a bitch to remove. I broke apart brake pads while removing drums. I replaced the drums and the problem went away.
 
#7 ·
Just because I'm bored and feel the need to contribute to this thread...

Rear wheels are actually supposed to engage before fronts. That's what the proportioning valve does. However, it's *normally* not noticeable to the driver.

If the brakes themselves aren't out of adjustment (yes, self-adjusting drums can get out of adjustment, you usually fix this by driving in reverse a little way, apply the brakes, repeat a few times.) or in some way damaged/defective, you might have a bad proportioning valve.

My '90 IROC-Z had this issue, and that was the culprit.

Just something to keep in mind.
 
#13 ·
First off, if they are too far out of whack, the self adjusters will usually not "fix" things. Furthermore, self adjusters like to gum up, then they won't turn, and therefore don't self-adjust anymore.

Second, if they were too loose, they certainly wouldn't lock up first. Instead, he'd be complaining of a shitty pedal.

They could be adjusted a bit too tight, but that's not likely.

The likely culprits are:

- Something was assembled incorrectly
- Leaky wheel cylinders
- Some other 'moisture' problem
- Drum out of round

Now, since the original poster says this only happens in the early morning, and then it goes away, we can certainly rule out a few things. Namely the drums out of round - they certainly don't round themselves out after a few miles. I would check over the assembly very carefully and check the wheel cylinders. If it is a moisture issue, it may go away when the weather changes, and you might have better luck with a different brand of shoes.

- Frank
 
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