Brake pedal sucks. Please help.

[Austin Stephens]

I’m 20 and normally do all my own work and if I need help my dad who has been working on cars since the 60’s normally knows what to do and then I have a mechanic friend that I use as a fresh set of eyes when I need them. With all that being said none of us can figure out what is wrong with my brakes in my 1998 2dr 4x4 Tahoe. My pedal goes to the floor but once it gets there it’s like a normal pedal but the rest of the pedal travel has no resistance. I’ve replaced and adjusted rear wheel cylinders and shoes, I’ve put in a new abs module which I had bled with a scan tool multiple times, 2 new master cylinders (bench bled before install), new front pads, and a new rear brake line. With the rear jacked up on stands when I put my truck in drive and hit the brakes the rears don’t start to stop until the pedal is at the floor. And because I was curious I even adjusted them to where they were pretty difficult to get on and off and it didn’t make a difference. With all that being said I don’t hear any hissing that indicates a vaccuum leak but when the pedal is almost to the floor I can hear kinda like a groaning or creeking coming from what sounds like the booster. If anyone can help that would be awesome!

 

[Austin Stephens]

You guys are amazing for helping thanks so much.

 

[letitsnow]

Do you get a good stream of fluid out of the bleeders for the rear brakes? If not, you could have a bad rubber brake line back there.

 

[JackE]

I would start by putting a line clamp on the 3 rubber lines, both calipers and the rear line from the frame to the axle, then step on the brake pedal to see what happens. If there is no change, the problem is before the clamps. If it's hard as a rock, your problem is after one of the hoses. Take one clamp off at a time and check the pedal. When it goes soft, you know where to look for the problem.

Don't get too upset when you don't get a quick response. Not many of us live on our computers with nothing else to do. Be patient, someone will usually get to your problem. Sometimes posts are rolling so fast, you might post something in the morning and it is on the third page by noon so it gets overlooked. If you do have to bring your post back up to get it addressed, don't be rude and sarcastic, that often turns away those willing to help.

 

[RichLo]

You guys are amazing for helping thanks so much.

I didn't respond because there was an identical topic literally right below yours in the brakes section with tons of great help in there. If you even took a glance in the first page of the brake section before posting this thread you would have seen it. It doesn't take a whole lot of searching to find the first thread in a dedicated section for the problem you are having.

https://www.gmt400.com/threads/low-brake-pedal.43779/

Also, not a great way of starting your first 2 posts in this (or any) forum by ignoring any efforts of searching then coming back with a sarcastic response.

 

[jkeaton]

Kids....

 

[Austin Stephens]

Sorry I’m just agitated with my truck and it’s my daily so I need to get it fixed asap. I’ve already looked through that thread and I wanted to make a post of my own because his truck and my truck have differences. I will try clamping off the lines and yeah I’m getting a good stream of fluid from the rear but when I bleed them the person holding pressure on the pedal feels the pedal go down slightly but when I bleed the front the pedal goes way down. And I have already replaced the rubber hose at the rear axle.

 

[jkeaton]

You have or have not replaced the booster?

 

[Austin Stephens]

I haven’t that’s one of three things I haven’t replaced. That and the front two calipers

 

[wheelman]

If the booster is bad you will hear a air leak.a steady one.new master can be bad.if it's a hydraulic system.there is special bleeding for that

When you bleed the brakes.back brake pads should be adjusted.but then.right rear.left rear..right front..left front.

Now front rubber brake lines could be bad.but most times if one is bad.brake will hang up and not release.

Hope you bought a new booster and not rebuilt.