Brake issues

[Jekyll73]

Ok guys, maybe you can help me out. I have a '99 Tahoe and every time I hit the brakes, my pedal goes down about a quarter of an inch and then stops but then I really have to push on the pedal to get the brakes to engage and even then they don't always slow the truck down. When I first push on the pedal, I hear a hissing sound. I replaced my master cylinder a few days ago and all the air has been bled out of the lines. My first thought when all this started happening was the ABS system had failed so I pulled the ABS fuse to disable the system. It didn't help in the slightest So I am still having the issue. Any thoughts as to what might be causing the problems that I am having?

 

[RED TAHOE LS]

I would remove the REAR brake drums and check the linings. JMHO
David g.

 

[Jekyll73]

I put all new rear drums, shoes, new wheel cylinders and hardware just in december as well as new calipers and pads for the front.

 

[mtl111]

You said you hear a hissing sound...correct? When you hit the brake pedal, is the pedal VERY firm or hard? If you have hissing and a hard pedal, I'd say it's the vacuum booster. I had a 99' 4wd Suburban years ago that had those symptoms and that was the issue.

 

[Jekyll73]

Exactly, a hissing sound and then the brakes are very hard and I practically have to stand on the pedal fir the truck to stop. I am currently in the middle of replacing the vacuum booster now.

 

[mtl111]

Let us know if that fix's the problem. The worst part of that job is the stupid clip on the brake pedal arm! Lol

 

[Jekyll73]

That is exactly what I am fighting with right this second. Lol. I will post if it fixes that problem

 

[mtl111]

Seems like I used a small screwdriver and some hemostats to get that clip off, can't remember how I actually did it though! Lol

 

[Jekyll73]

I had a small screwdriver and a long pair of needle nose pliers. Talk about a pain!!

 

[Jekyll73]

Finished with the truck. Was definitely the brake booster. No more hissing when I apply the brakes and the pressure is smooth, not spongy or hard as a rock. Thanks for the input guys