[redline_or_nothing]

21 zl1 1le with 6spd, 12k miles. I don't track the car but do go for spirited drives on twisty mountain roads. I bought the car last year with 3600 miles on her. The very first spirited drive i went on, after 5 minutes of aggressive braking, the brakes start to hum and the pedal gets stiff with a huge loss of braking power. When this happens, i can tone it down for 5 minutes and then the hum is gone and pedal is normal until i start using the brakes aggressively again. I did the brake booster test where i pumped the brakes with the car off and got the stiff pedal and then started the car and the pedal does go down a little so i dont think its the booster. Fluid is full also and i don't see any cracks in the vacuum line. I did replace the pads but the old ones were oem and still had plenty of pad material. In the picture, the old pads are in front of the new ones. Has anyone else experienced this issue? Thanks for any insight.

[Christian1LE]

Have you checked the actual pads, they might be gone.

[cdb95z28]

Sounds like pad fade.

[Jofu]

I also would look if the pads are OEM ones or not. Maybe the original owner was willing to forego some braking power for less dust.


Geoff

[Checkmate1]

Lots of owners put ceramic pads like Powerstop Z26 pads for eliminating brake dust. Flip side - loss of braking power when you push it properly.

[redline_or_nothing]

I replaced the brake pads with new oem pads but the old ones still had plenty of material. I added a pic to the original post. I will hopefully get a chance this weekend to try out the new pads.

[ctrlz]

Those pads look pretty good, and based on the rusty surface I'd guess they were the stock semi-metallic and not the Z26 ceramic.
I would look over the brake booster pump (behind left headlight) and associated check valves in the plumbing. Since you bought used, there is chance somebody "adjusted" things.
I don't think you are overheating the brake fluid.

OTOH, if you are low on booster vacuum, it should set a DTC:
https://www.camaro6.com/forums/showp...5&postcount=16

[NG329]

Originally Posted by redline_or_nothing

21 zl1 1le with 6spd, 12k miles. I don't track the car but do go for spirited drives on twisty mountain roads. I bought the car last year with 3600 miles on her. The very first spirited drive i went on, after 5 minutes of aggressive braking, the brakes start to hum and the pedal gets stiff with a huge loss of braking power. When this happens, i can tone it down for 5 minutes and then the hum is gone and pedal is normal until i start using the brakes aggressively again. I did the brake booster test where i pumped the brakes with the car off and got the stiff pedal and then started the car and the pedal does go down a little so i dont think its the booster. Fluid is full also and i don't see any cracks in the vacuum line. I did replace the pads but the old ones were oem and still had plenty of pad material. In the picture, the old pads are in front of the new ones. Has anyone else experienced this issue? Thanks for any insight.

Check the fluid level in the reservoir and make sure the last hacks who worked on it didn't overfill it -- there is a fill line in there that should not be exceeded.