I had my car lifted up in the garage trying to diagnose a rear end noise. I noticed that with the transmission in drive I can barely get the rear wheels to not turn. I have to push the brake pedal to the floor HARD for the rear tires to stop moving.
I guess I could bleed the rear brakes and see if there is any air, but I thought i'd see what people here think.

Thanks,
Rob

 

If It Is Drum Brakes,try Adjusting Them.if Disc Then A # Of Things Could Be Happening,clogged Lines,bad Proportion Valve,empty Master Cylinder.

 

i dont know if 93 z's came wih discs or not, i'm pretty sure all z28s had rear discs
if it is a drum rear end it is very common for the drums to need adjusting

 

Pretty common. That's why it's so easy to do a brake stand.

 

yea i have the exact same problem right now

 

It has rear discs. I thought it might be a problem when I almost slid through my garage door at 2 mph.

 

I bled the rear brakes, as well as the ABS box thingy in the engine compartment. It made no difference. I did a search on this problem and found that it seems to be a common problem that nobody posts an answer to.

 

The answer is: "that's the way it is".

Most of the braking is done by the front brakes. The backs just aren't very robust.

 

My Jeep with 35's and drums stopped the rear wheels better. This cannot be right...

 

I have my '97 Z28 in the shop now for the same issue. Seemed to happen soon after I replaced the pads on the front. Had to push on the brake a little harder than normal. I thought it had to do with the new ceramic pads that I had put on, but finally noticed that the rear brakes were not working like they should. The mechanic working on it is at a dealership and has replaced the rear calipers and also tried replacing the ABS valve body with no luck. He said that he also has another '97 and a '96 in the shop also with the same issue. I think most of us know that the rear brakes don't do the majority of the braking, but I sure wish someone knew something about this issue.

 

Couldn't a proportioning valve be installed so that you can adjust the front and rear braking percentages? Seems like it would work. But you don't want your rear brakes doing too much of the braking, since most of the weight is in the front.

 

Notice that the rear brake pads and calipers are significantly smaller than the front's, the pads themselves are literally half the size.
I got my rear's working best by adjusting the allen wrench on the back of the caliper for the emergency brake, and it effected the normal braking as well for some reason.
A clear example of just how pitiful the rear brakes are can be found by trying to brake just using your E-brake.

 

It makes me wonder if I did something not quite right when changing the front pads about 8mo. ago. I didn't realize I had a problem until I actually tried to use the emergency lever(which I have been told by my machanic just applies the rear brakes) and it did not stop the car quickly at all. From what I have read so far it sounds like there are several people having this issue.

 

I guess you can see from most of the replies that it is most common. Whether you choose to believe that is the way it is, is up to you.

 

most people have an improperly adjusted rear emergency brake as well. Shoebox's site probably has a schematic showing where the adjustment allen head screw is you turn to adjust the free-play on the E-brake