Suspension & Brakes - Braking Problem - Slow Braking at High Speeds




Weist
11-22-2009, 08:51 PM
1999 Trans Am

When I am cruising at 80MPH and have to hit my brakes to slow down or come to a complete stop, it feel like my brakes are skipping or not catching. I press it all the way to the floor and it keep rolling, any idea what the problem could be?? bad caliper, air in ABS system, etc. (I had my buddy take me for a ride in his car and brake fast and it almost comes to a complete stop in no time, where as mine takes longer)


Foxxtron
11-22-2009, 08:55 PM
When you "press it all the way to the floor", does the pedal feel spongy? How old is your brake fluid?

Also, are there any signs of noise and or other strange pedal feel?

Weist
11-22-2009, 08:59 PM
Na everything feels good..I changed the pads, fluid and bled the brakes a couple months ago...I only topped the fluid off from bleeding them so its a mixture of the new and old stuff


Foxxtron
11-22-2009, 09:06 PM
What pad compound are you running and did you follow the proper bed-in procedure?

Also, when you bled, you did bleed until no more bubbles and/or new brake fluid began to flow into your bleed bottle, right? Did you also reset the ABS module afterwards?

Sorry for the questions, but the more detail you can provide the more forum views can chime provide help.

Weist
11-22-2009, 09:13 PM
I got the brake pads from AutoZone, they where the Duralast Golds.

Yeah I bled everything in properly just how you stated but I did not rest the ABS module(How do you do that)?

From talking to some other guys they kinda think that i will have to take it to the shop and have a TECH2 bleed the ABS System...IDN though

Foxxtron
11-22-2009, 10:07 PM
There are two methods of resetting the module. The TECH2 method is the most reliable method, or triggering the ABS whilst driving in a SAFE area is another. Either method will of courser require to properly bleed again.

With the details that you've supplied, I do believe that the problem is mostly down to rotor surface to pad surface related. Whilst it's not always required, if I change pads and don't change rotors (unless absolutely needed), I ensure that I remove the previous bedded in material from the rotor so that the new pads will less likely risk contamination from the old material. Again, depends on what compound is present, but generally I don't like to risk it.

Also, what pads are installed on your friend's car? I'm not completely sure about the approximate compound that Duralast Golds have (Ceramic, Composite, semi-metallic, etc), however my best experience with performance street pads on the 4th Gen F-body have been Hawk HPS's.

With all of that stated, you should inspect the caliper pins as well as the "installation hardware."

Just my .02

therealcreeper
11-24-2009, 12:49 AM
Duralast Gold's are ceramic. I have them on my car. pretty good pad considering it's made by autozone haha. i've used them for autox and some other aggressive driving and they've done pretty well. i agree that hawk HPS's are better but these aren't terrible. once they get hot the pedal becomes very sensetive. after a few autox laps you just tap em and they grab like nobody's business. higher speeds(120+) leave some to be desired though.

LS1CMR
11-24-2009, 07:19 PM
i have the same problem in my car, i have installed new stainless lines and completely flushed the system with new fluid. and i still have the problem, i am leaning towards the booster next because there is nothing else wrong with the system, when i park the car at night and go to it the next morning the pedal is rock hard telling me the booster is bleeding down, so all i can think of is at high speeds i am not getting enough vacuum to supply the power brakes.

Foxxtron
11-24-2009, 10:00 PM
i have the same problem in my car, i have installed new stainless lines and completely flushed the system with new fluid. and i still have the problem, i am leaning towards the booster next because there is nothing else wrong with the system, when i park the car at night and go to it the next morning the pedal is rock hard telling me the booster is bleeding down, so all i can think of is at high speeds i am not getting enough vacuum to supply the power brakes.

I'd say this is the case for the OP as well if this is what the behaviour of the first post's description.

What I usually think of with "skipping and catching" is when the pedal is engaged firmly and there's a sort of feedback that's described by the phrase.

lo_jack
12-01-2009, 09:36 AM
1999 Trans Am

When I am cruising at 80MPH and have to hit my brakes to slow down or come to a complete stop, it feel like my brakes are skipping or not catching. I press it all the way to the floor and it keep rolling, any idea what the problem could be?? bad caliper, air in ABS system, etc. (I had my buddy take me for a ride in his car and brake fast and it almost comes to a complete stop in no time, where as mine takes longer)

Does it feel like the brakes are trying to grab at speed but just not physically able to get the job done, yet at regular speeds (sub 50) everything is fine? I had this same scenario happen now on several occasions on the highway myself, but my vac gauge on the manifold (t'd off from the MAP) always reads normally.

What causes a booster to not work/be insufficient at highway speed?