New brakes not working correctly

[greendy23]

I have just put new Hawk pads and ATE rotors on my 04 Accord LX. Braking seems to be fine at low speeds, but when traveling at highway speeds and braking hard, the brake performance is horrible, the pedal goes to the floor and stopping power is not nearly what it should be. I have bled the system 3 times and no change. Any ideas?

 

[E_SolSi]

when you bleed the system does it get better for a little while??
are you getting any air out of the lines??

if there isnt any air in the system it sounds like you might have a bad booster or master cylinder??

 

[greendy23]

When I bleed I don't see any air coming out of the lines and the performance stays the same.

 

[E_SolSi]

and your fluid cup is staying full??

 

[E_SolSi]

is there any noise when you press the brakes with the engine running (like a hissing or anything else?)

 

[greendy23]

Brake fluid stays the same level, I'm positive that there are no leaks I have been keeping an eye on the fluid level. and no noise is made when the pedal is pushed.

 

[greendy23]

I can press the pedal up to a certain point and the braking power increases, but pressing the pedal further puts no additional effect on the braking power

 

[E_SolSi]

i would test the booster... if it tests fine, replace the master cyl

 

[greendy23]

the booster seems to be holding the vacuum fine. I can pump the brakes with the car off and the pedal becomes progressively harder. thanks tho!

 

[E_SolSi]

what happens when you hold the brakes (after getting the pedal pressure up) with the car off.... does the pressure drop off??? how quickly?? what about with the car running??

from your description it definitely sounds like there is a leak somewhere in the system

 

[greendy23]

After I get the pressure up and hold the pedal, the pedal stays in place, no sagging or anything. same thing when the car is running no loss in pedal pressure.

 

[greendy23]

is it possible that even after bleeding 3 times there is still air in the brake lines? if so what is a sure fire way to make sure that all the air is taken out?

 

[phyregod]

How are you bleeding them?

There is a bleeder tool called a mighty vac that sucks the brake fluid out pretty fast, good for getting hard to bleed lines done. Tool costs like $35 at pretty much any parts store. Try to find a metal version if you can.

What prompted you to replace the pads and rotors in the first place? Was this general maintnence or was there a preexisting problem?

 

[Korax]

Vacuum bleeding is always the best choice. Normally gravity is enough for brakes, unlike those damn hydro trannys. You should def do it if all you did was gravity and you are absolutely positive it has no leaks.

 

[greendy23]

I replaced pads and rotors due to this problem. I'm bleeding the brakes using the old step on the pedal open the bleeder method with 2 people. I'm going to try bleeding again tomorrow, and yes I'm absolutely positive that there are no leaks.

 

[HATCHET_HONDA]

perhaps this is an ABS issue??

 

[greendy23]

abs does not go off when braking

 

[Ethan]

Had this issue with my friends lude. we never git it right. but i honestly think he had caliper issues. too broke to buy new ones.

 

[newb]

You can crack the bleeder valve a lil and let the car sit overnight with the cap off the reservoir, sometimes that'll get it.

It sounds to me like you may have a problem with calipers or lines. Your holdin pedal pressure and building breaking force to a certain point then you quit buildin brake force without loosing pedal pressure, correct?

That could be a kinked line or a bad seal in the caliper.

 

[greendy23]

That is correct, I never lose pedal pressure and i can never reach maximum braking force even with the pedal pressed as hard as possible. braking power increases up to a certain point then does not increase.