A month ago, I changed out my OEM standard brakes. I installed OEM Brembo Calipers, new Stoptech Two-Piece slotted rotors, new RacingBrake shims, new Endless pads, and new Stoptech Stainless-Steel lines all around. The system was bled with new Motul DOT4 brake fluid.

Here is the problem with the new setup. I understand this new setup is not supposed to be as "grabby" as my old OEM standard setup, and I know that OEM pads offer higher performance in cold panic braking, but I still feel as if my new setup feels too soft.

When I first press down the brake pedal to stop the car, the pedal travels almost 1/2 the way down before there is any significant stopping power. There is no extended travel when I first press down the brake pedal. When I pump the brake once, all of a sudden, there is a significant amount of braking force applied by pushing the pedal 1/16 to 1/8 in from rest!

I do not see any signs of leaking at the master cylinder or at the lines. I have bled the system twice since I noticed this problem, and have not observed any trapped air. I have also removed, reset, and re-bed my brake pads. However, none of this has made any difference in pedal feel.

Any expert advise offered would be greatly appreciated.
Thanks in advance.

 

I would try to bleed it again. Tap the calipers with a rubber mallet. I had to bleed it 3 times till the pedal felt right. each time we "thought" we got all the air out but each time we got more bubble even after thinking we didnt have anymore.

 

I suppose I can try to bleed it again.

However, given my description of the problem, is there any possibility that some other component of the system is faulty?

 

Try taking out those RB shims and see how it feels. I had the RB shims once and like you described the pedal felt squishy. I bled and bled and couldn't fix the problem. Then I took out the RB shims and noticed the rubberish coating on the shims were chewed up. I left them out and the pedal felt instantly better. It was the rubbery coating that caused more pedal effort.

 

You can add a Stillen MS damper. That helped mine a little.

 

Did you install the brembos in the correct side? And did you bleed in the correct order?

Having to pump the brakes to get pressure is a classic sign of air in the lines.

 

I really hope it isn't the RB shims causing this condition. Those shims make a huge difference quieting down the brakes. Nevertheless, I would rather have a squeaky firm brake over a soft quiet brake.

I"m going to try other methods to fix it first, and if nothing works, I will remove the RB Shims to see if there is any difference.

Does anyone else have experience with RB Shims?

 

I was actually looking at this product yesterday. It looks pretty easy to install, but I am worried if this works with the VRT Front Strut Bar, since they look to use the same mounting points. I contacted VRT about this yesterday, but they haven't replied to me yet.

Do you recommend the Stillen Master Cylinder damper? How much of a real difference did it make for you?

 

Hahaha .. I HOPE i installed the Brembos correctly. But just to have all bases covered, how would I be able to tell?

 

Well if the mounting backets are symmetrical (sp), then it's possible to install them on the wrong side. It depends on if the brakes lines and such still lined up okay. I know you can install the 4 piston 300z calipers either way. But the problem is when you do that, the bleeding nipples end up on the bottom of the caliper when they should be on top. But it's just a guess.

 

Understood - I remember that all the calipers have symmetrical mounting points, so it would be pretty stupid if I installed them backwards. I am pretty sure all my bleeders are pointed up, but I will check and make sure.

 

I just contacted RacingBrake to report the problem I am having and to ask if they knew anything about their shims causing the pedal to sponge. The rep took my info and is asking one of their engineers now, so hopefully I will get back an answer soon.

 

Mines did the same exact thing when I installed and bled them. I thought something was wrong. took it down a road and did a couple of stop and goes and the brakes began to work fine. My friend also had the same problem and he did the same and it worked also. I guess it must be the abs system learning the new brakes.

 

Thanks for all your help so far guys!


Some updates.

It looks like it might very well be the RacingBrake shims. An engineer over at their company returned my call and said that there is sometimes an issue with a tab on the shims being bent, causing an air gap between the pad and the caliper.

I am going to freeze my butt of and take out one of the front shims and send them pictures. RacingBrake says if this is indeed the issue, they will send me a new set for all four corners with re-designed shims that correct the problem.

I'll keep this thread updated for all those who are interested.

 

Good deal. Let us know how it turns out.