Brake problems

[mcm12263]

I have a '97 LS Blazer, when I'm driving and i step on the brakes, at first they work normal then after a few seconds, the pedal gets mushy (like it is loosing its fluid) and then the pedal rumbles and makes a strange groaning sound (I think the ABS engages) But, I am not stepping on the pedal hard at all. Sometimes, it even does it when I am sitting still with my foot on the brake. There is no light on or codes that I know of.
Can someone please help me with this problem.

[MT-2500]

Originally Posted by mcm12263

When I'm driving and i step on the brakes, at first they work normal then after a few seconds, the pedal gets mushy (like it is loosing its fluid) and then the pedal rumbles and makes a strange groaning sound (I think the ABS engages) But, I am not stepping on the pedal hard at all. Sometimes, it even does it when I am sitting still with my foot on the brake.
Can someone please help me with this problem.

Always give year make and model.
Any ABS codes or abs lights on?

[mcm12263]

Thanks for the info on adding year make model. it's a '97 blazer. No the ABS light is not on although it does work (comes on when I start truck and goes out). When a friend of mine scanned it there were no brake codes.

[MT-2500]

Originally Posted by mcm12263

Thanks for the info on adding year make model. it's a '97 blazer. No the ABS light is not on although it does work (comes on when I start truck and goes out). When a friend of mine scanned it there were no brake codes.

Perdel dropping and kicking around says ABS is acting up/kicking in.
Lot of times a wheel speed sensor.
Check wheel speed sensors on a good ABS scanner.
It needs checked real good on a ABS capable scanner.
And always test after it acts up and before turning ign off.

ABS Codes may clear and reset when ign is cycled off.

Also beware of ign switch problems on a 97 model.

Good luck

[blazee]

An ABS capable scanner is the best way to check out the wheel speed sensors. You can do a quick test with a volt meter that reads ACmVs, though. Raise the front tire, disconnect the wiring connector for the wheel sensor, connect your leads to the terminals in the speed sensor connector, spin the tire by hand and look for at least 350 ACmVs. If you see less than that remove the sensor from the hub and clean it. Repeat for other side.

Just curious.... have you had one of your front wheel bearing/hubs replaced recently?