The situation:

Rotors are okay, pads are new but already broken in, fluid is brand new, I got bfg-steelflex brake lines, the brake has been bleeded and checked four (!) times for air inside the system... no more air bubbles.. The system is tight. Brake pressure is fine and is stopping the car the way I expect it... there also seems everything allright with the calipers...... but:

Still the brake pedal is soft and has do dive down to deep until brakes build up stopping power.

What now ?

 

Are you guys sure it's not your brake lines? The last few that have had complaints about pedal feel I seem to recall had aftermarket lines. I know the theory on having them, but it seems odd that it's most common in cars with non-OEM brake lines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR5874 &raquo;</TD></TR><TR><TD CLASS="quote">The situation:

Rotors are okay, pads are new but already broken in, fluid is brand new, I got bfg-steelflex brake lines, the brake has been bleeded and checked four (!) times for air inside the system... no more air bubbles.. The system is tight. Brake pressure is fine and is stopping the car the way I expect it... there also seems everything allright with the calipers...... but:

Still the brake pedal is soft and has do dive down to deep until brakes build up stopping power.

What now ?

</TD></TR></TABLE>

If I were you, I would find a slippery surface and slam on your brakes about 30 times, making sure you are into ABS every time. Then go back and bleed your brakes. Things should get much better.

Do a search on posts by 1greyteg... (his name is Anton) he has had the same problem for over a year and figured out it is the ABS system.

 

is the interior diameter of your aftermarket brake lines the same as stock? If it is bigger it will take more pedal travel to build the same pedal pressure.

 

The pedal felt soft before with stock lines... Now it feels the same with aftermarket lines... They came in at the same time like the new fluid

 

are you using upgraded calipers or just the stock ones?

 

My brake setup in short:

Stock calipers, stock rotors, Ferodo 2500DS pads, Dot 5.1 fluid, bfg-brakelines, brake cooling hoses, OMP pedals

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR5874 &raquo;</TD></TR><TR><TD CLASS="quote">My brake setup in short:

Stock calipers, stock rotors, Ferodo 2500DS pads, Dot 5.1 fluid, bfg-brakelines, brake cooling hoses, OMP pedals</TD></TR></TABLE>

Just do the ABS service... search through threads by 1greyteg and you will see that we both changed master cylinders, lines, bled and bled and bled and change stuff over and over...the ONLY thing that fixed the pedal travel issue was activating the ABS system multiple times and bleeding the lines in the correct manner according to the Helms (driver front, passenger front, passenger rear, driver rear). I used to start furthest from MC (pass rear) then driver front, then driver rear and then pass front, as listed in my '98 helms, but the newer Helms has a different pattern.

 

Okay, I will try.

But the reason why I call the "sorrow" and not just a problem is, I`m leaving my home for two weeks now and when I come back, I`m heading directly to a race event..... I will not have enough time to fix the brakes before..

Okay... I see it starts to rain outside.. Maybe I find a a place to activate the ABS..

Hmm.. What happens if I plug off the ABS ?

 

Sven if you want a good test to know if the ABS is the cause of the trouble as David is mentioning just unplug the ABS unit and go for a drive.

I did that test at an autocross event because the pedal travel was so bad that I would go from no brakes to blowing through corners without the ABS even activating. We disconnected the ABS module plug and took it out again, the pedal did not rise any but didn't sink nearly as much and the brakes again worked so well that I'd lock them up every time I applied them and on my first run this way I dropped a full second.

Like Dave said I went almost a full year and several track events with this scary brake issue, doing what I was told to me in the Helm's and online and by close friends that were trying to help. I went as far as multiple bleeds with different fluids, changed in a brand new Master Cylinder, went through new pads, rotors, checked the caliper action and everything we could think of, still soft/sinking pedal and no ABS.

I contacted a guy named Mark Basch (a well known NSX mechanic) on reference from Andie Lin From Cobalt Racing after being totally frustrated. He explained that this type of problem is common in the NSX and has to do with exercising the ABS system occasionally and a possible ABS solonoid getting stuck in the open position.

He explained how to activate the solonoids individually with a 12V soource OR the other way was to do exactly what Dave and I did and go out in the car on a slippery or loose surface and just ropming on the brake pedal activating the ABS multiple times (in my case over 100 times since I wanted to be VERY sure). And then do 1 or 2 full flush bleeds, (in my case opening the bleeded valve ont he caliper only about halfway and maintaining pressure as well as using a one way check valve on the bleeder bottle and using the same sequence as Dave mentioned fromt he Helm's manual starting at the drivers side front caliper and going clockwise). Bleed until the pedal is again firm and then take the car out for a spin and make sure the issue is resolved.

I too was confused and was at the end of my rope and didn't know what to believe but followed the instructions and voila after our science experiment, ABS again works,a nd the pedal is firm as it ever was and the car stops on a dime and especially with good R pads and half worn Azenis.

Here is my post discussing my problems originally:
https://honda-tech.com/zero...age=1

Some posts where Chris (Onyx00) discusses his brake problems which are similar to ours and I discuss what we did to remedy mine:
https://honda-tech.com/zerothread?id=802365
https://honda-tech.com/zerothread?id=850276
https://honda-tech.com/zerothread?id=898034
https://honda-tech.com/zerothread?id=842779

There's a slew more, just search a bunch and look under my screename, Davidnyc's and Onyx00's.

Let us know how it all goes.