I just had my brembo blanks and porterfield R4-S pads installed today, and entire brake system flushed with Valvoline Synthetic Hi-Po brake fluid (dot3/4). I noticed initially, the pedal is very very firm. A lot less travel than normal.

After doing the bedding in procedure (it was tough to find space for five consecutive quick stops to fade the brakes), braking is better now, but the pedal is still very very firm. I know air in the system produces a mushy pedal, but what could cause a firm pedal? The synthetic fluid, or maybe I am just not used to the feeling of normal brakes. Or maybe the feeling will go away when the pads properly bed in. Any ideas?

 

hey Eric

ummm, is it a firm pedal or hard pedal? dont complain about a firm pedal thats good! Hard pedal is something else tho. Ive always been impressed with the Porterfields. Even some guys i simply slap Porterfields on they still have good bite.

 

I would say a firm pedal. I suppose that is good, but initially I was mislead a little since I was used to a certain firmness which signaled "hard braking power" with the stockers, and when I feel that pressure with the Porterfields, I am barely stopping since the pedal is depressed much less. I can step down more, and the car stops, but the pedal effort seems a bit excessive.

I was just a bit concerned because the pedal is firm enough to make you think you are slowing down quickly, but you really aren't, and I have to step down even more to stop. It's not a mushy feeling, and it's not a fully depressed hard pedal either. Maybe what I am feeling is just the result of the synthetic fluid.

 

no the brake fluid wont make a difference in pedal feel. Dot 3 Dot 4 all feels the same way. The advantage is the higher boiling point.

 

Where did you get the brembo blanks? What exactly are they? Are they what you see on the side of the caliper? Thanks.

K

 

Best 1/4: 14.846@95.58 mph(corrected for altitude) In a '95 GXE auto with 150,000 miles!(I cant wait to see what the Supercharger does!)




hey kirk...are you getting a s/c....?????thought you were getting n02? or are you getting both?

 

Yes, a SC. No NO2 for now, but that is still an option I will look into. I want to see what the SC will do to my 1/4 and then think about NO2. Plus I dont know if my engine can handel both. You have a good eye, I just changed my sig about 30 min ago.

Kirk

 

Had a similar problem when I installed the Stillen Metal Matrix pads with cross-drilled rotors. The initial braking in the morning was horrible coming down my driveway. I really had to stomp on the pedal to make the car stop. Once I had warmed up the brakes they were better, but they always took more input to make them stick. I changed to Porterfields in the front and don't have that problem any more. Still running stockers on the rear. I'm surprised you are having that problem. Did you get cross-drilled rotors, slotted, or stock replacements? I've always wondered if cross drilling reduces the contact area enough to result in the problem you are having.

 

No, these are brembo blanks, not cross drilled or slotted, just vented discs like the stock rotors. See the odd thing is that if I stand on the brakes, these things bite and the car stops on a dime, much better than stock. But with moderate pressure it just seems like the pads are not sticking as well as the stockers. I really have to put pressure on the pedal to stop the car.

Oh and to answer the other question, I got the rotors from Porterfield as well. They are brembo blanks, JBR-505 for the front, JBR-752 for the rear.

 

That's really strange. I've had pretty good success with the Porterfields on my front. Are you sure you got the "street" version...I've heard the racing version is a disaster on the street.