How much brake pedal "play" is normal before brakes engage?

[derekjl]

This seems to be a common issue on these OBS trucks and SUVs. We've now had four of them and they have all had this, might be normal or not so I'm not sure. Basically, there is a slight amount of "dead space" in the brake pedal before they actually activate. Now, I'm not talking about a low brake pedal or one that fades/goes to the floor. Once the brakes come on the pedal is very stiff and does not give at all. There is just some play at the top. This can get kind of annoying because you have to anticipate having to brake maybe 1-2 seconds before you actually need to. Master cylinder and brake booster do not appear to be leaking at all. I'm guessing I could start with a brake fluid flush and proceed to make sure the rear drums are adjusted correctly? Any input is appreciated. My other cars do not do this, the moment you put your foot on the pedal the cars will begin to brake.

 

[Larryjb]

I usually sense more brake pedal "play" as the pads wear. The amount of play would also be affected by the types of brake pads, condition of calipers, rotors, brake fluid, etc.

If I understand correctly, organic pads have good bite, but will fade much easier. I had ceramic pads once, and hated them. They didn't work well until they got good and hot. Semi-metallic has always been a good balance for me.

 

[derekjl]

I usually sense more brake pedal "play" as the pads wear. The amount of play would also be affected by the types of brake pads, condition of calipers, rotors, brake fluid, etc.

If I understand correctly, organic pads have good bite, but will fade much easier. I had ceramic pads once, and hated them. They didn't work well until they got good and hot. Semi-metallic has always been a good balance for me.

I should have added, the front pads and rotors are brand new. The condition of the rear shoes and drums are unknown.

 

[Larryjb]

What pad material did you use? Did you flush the brake lines? Did you like the caliper guide pins and all other lube points? Rear brakes may need attention too.

 

[EliminatorDave]

I am in the same boat. I bought a 98 2 door LS 4x4 Tahoe for my oldest sons first vehicle, but the brakes are so bad my wife and I don't want him to drive it. I thought it just needed new pads and a good air bleed, but that didn't do the trick. I had a mechanic friend power bleed the system and check all the lines, pads, sliders etc and they were all almost new and in good working order. He said these rigs came with crappy brakes and thats what you have. I bought a 98 GMC Z71 half ton new in 98 and dont recall the brakes having so much dead play in the pedal, but it was a heavy half and I still recall it having oddball rear shoes and over sized wheel cylinders when I did the rears brakes.

I am looking for the silver bullet fix. Anyone know of a kit that fixes the soft, long travel pedal? I've seen the posts about Hydra-boost upgrades, not opposed to going that route just haven't seen a complete kit for sale. If need be, I'll ditch the ABS and stock vacumn booster, master cylinder and proportioning valve if thats the only way to fix this crap. Just seems like a waste as the ABS works.

I'm looking for the confirmed fix, in a box, anyone have any suggestions?

 

[bsamoul]

I would be interested as well. I just replaced all 4 brakes and hoped that my pedal would have been higher.

 

[Squirrelsmith]

I test drove a 94 2 door the other day where the brake take up was alarming felt like it could have been a foot! On the other hand I recently drove a 99 with very little take up where everything felt tight... for what it's worth.

 

[Larryjb]

I test drove a 94 2 door the other day where the brake take up was alarming felt like it could have been a foot! On the other hand I recently drove a 99 with very little take up where everything felt tight... for what it's worth.

I'm convinced the quality and type of pad material affects the pedal feel and even the pedal travel quite a bit. Someone gave me ceramic pads once and they did not feel like they had any decent grab until they got good and hot. I hated them.

 

[Greg Carrasco]

I have a leaking(very small leak) master cylinder and is causing my brakes to do the same I haven't replaced it yet so can't confirm it works

 

[Kelsda]

Rear disc conversion I did it big difference bought from Little shop mfg all these rear drum brake vehicles go half way to the floor before working

 

[Scottydoggs]

if you guys have hydro boost you might need to bleed that system. air in the lines will give ya mushy pedal for sure.

 

[dubyagee01]

if you guys have hydro boost you might need to bleed that system. air in the lines will give ya mushy pedal for sure.

New caliper lines help a lot too.

 

[Squirrelsmith]

i swapped my vacuum booster to a hydroboost. i estimate the take up to one inch and the pedal is very firm.

 

[Sean James]

I have 3. '98 tahoe 4wd with mechanical shift on floor. '99 tahoe "auto" push-button. '99 Yukon "auto" push-button. All 5.7's 4l60E's 4wd's. All pretty much stock. They ALL do the same thing. When I first got my '98 tahoe, I noticed that it was not as firm as my '95 Silverado. Went through the whole brake system on the '98 tahoe, everything checked out, and I didn't worry about it. It was my wife's truck and I had life insurance on her. Then I got the '99's and they seemed even worse. Lot's of pedal travel before engaging, and more travel before a hard stop. SO, for the '99 tahoe, I bought brand new front calipers, pads, and rotors for the front. NEW drums, wheel cylinders, and shoes for the rear. New rear brake lines as well. Bled (bleeded) everything twice, everything was new and perfect...and the same darn thing. It's just the way these trucks are engineered. They feel like it, but they don't go to the floor, far from it. They work perfectly, but they just feel spongy compared to other vehicles. If it is your daily driver, you will eventually get used to it and not freak out. As long as you don't have an ABS code or other issue, it's just the way they are.

There are millions of complaints about this, and tens of thousands of folks that have tried upgrades to remedy the issue, but most have little effect. Compared to newer models of light-duty suv's and trucks, the OBS tahoe's and yukon's have small underpowered rotors and drums, but they work. It's just something that must be gotten used to after time. I have read that GM did this for the "soccer moms", so that they had a soft "feel" and an easy to push brake pedal for women. But who knows. It could be an inherent design of the "then new" ABS system as well. I have not tried an upgraded master cylinder, but have read many posts with mostly negative results. Hydro-boost is costly, do your research first. And for what it's worth, Semi-Metallic shoes/pads are what should be used for our SUV's, they are the best combination of wear, stopping power and life for our vehicles.

And for those not mechanically inclined, if something seems wrong, please have a good shop take a look at your brakes, it IS the most important system on any vehicle.

 

[96-2D-Hoe]

You can tell if your rear shoes need adjusting by the height of the parking brake. If adjusted correctly the parking brake will only give 2-3 clicks, move 2 inches or so before it locks.

In my experience the biggest issue with my brakes has been getting any air and/or old fluid out of the ABS system. Once that is done they work great imo. Need a scan tool, or a gravel road to do that.

 

[Squirrelsmith]

I can tell you guys that hydroboost is a %100 confirmed fix. I did it for several $100 in parts. Many were junk yard. If you can pull it off it will fix this.