This afternoon I replaced my stock brakes with some OEM Brembos. After the swap, I bled them and everything felt fine. Pedal was good and hard. Once I start the engine though, the brake pedal feels a lot softer than before. It seems like it has a lot more travel before the normal resistance is felt.

Has anybody else who did the swap noticed this?

I'm wondering if it has something to do with different brake boosters between the Track and non-track cars.

 

this was how mine felt when i used the OEM non brembo master cylinder. Right away after i installed my brembo master cylinder that i obtained from the dealer, the feeling felt normal again and the pedal was short.

Even though other people told me they are the same master cylinder or whatever. Not sure what it was.

 

You still have air in the system. Probably at the master cylinder. I would bleed the lines at the master, to do this you need someone to push in the pedal as you crack the line loose. BTW if you look it up , they have the same part numbers between master cylinders.

 

The master cylinders are the same but the brake boosters are different.

 

I don't see how I could have gotten air all the way back to the MC though. I bled almost a whole quart through the system on just the front brakes. The pedal is good and firm during the bleed.

 

Took me a few rounds of bleeding to get my pedal firm when I installed my AP bbk. I broke down and bought a motive pressure bleeder, and it made the job cake, firm on the first try.

It was doing the same thing to me, firm when the car was off, but soft when engine was running. No idea why.

 

I know somebody with a power bleeder. I may have to recruit him to help with that. I'll wait till after I get the rears swapped out - that's going to be another adventure. I pounded on one of them but it did budge. I tried soaking the studs with WD 40 - we'll see tomorrow if that does any good.

 

PB blaster is your friend, works much better then wd40. Spray them with that, give it a couple hours, then go at them.

 

I did initially. It was a pain! I paid an additional 20 dollars on top of my alignment for a shop to power bleed them. After that everything was great. Peace of mind is a great thing

 

They like to trap air at that spot. Pressure bleed or cracking the lines loose will get it out.

 

+1 Wd40 does nothing. PB blaster is much better. I haven't found any bolt that PB blaster won't open.

 

You did both bleeders on each caliper right?

 

Yes, about three or four times on each.

 

I have and 04 Base and installed a used set of OEM Brembos (from a G35) and new braided brake lines - the pedal is much softer than I would like. I bleed the system often, before and after track days. I've never used a power bleeder since I've read that they don't work well, but I'm willing to try. Another consideration is a master cylinder brace. Stillen makes such a brace, but I'm having difficulty justifying the $140 investment for such a relatively simple item. If I do get the brace, I'll post a review.

Joel

 

looks like i need to order the brembo master cylinder to remedy this soft pedal issue.

 

No you don't. I pressure bled my brakes the past Friday and the pedal feel got significantly better. Drove the car all weekend in an autocross and the brakes worked fine considering that I haven't had time to bed them in.

 

That isn't enough. I have had to do bleeds and it takes like 10 times to really get all the fluid through well.

 

I did as others recommended and got a pressure bleeder. That the device that forces brake fluid into the master cylinder under pressure. You go around to each brake and bleed them as normal without ever having to get in the car and touch the brake pedal. Works like a dream

 

Yea I really need to get one of those. I always have to get someone to do the brakes for me. :P

Where did you get one from and how much?

 

do you run the risk of forcing air through the fluid with those?