Spongy Brakes

[Sieg]

I'm running a 7/8ths manual and have what I would consider a good pedal. I can stab it at 35-40 mph and chirp the fronts......if that means anything.

.........but I also have rear drums.

[chr2002ca]

Originally Posted by Sieg

I'm running a 7/8ths manual and have what I would consider a good pedal. I can stab it at 35-40 mph and chirp the fronts......if that means anything.

.........but I also have rear drums.

I can lock up my brakes also and my car now stops beautifully, so my setup is now working better than ever. I had that same problem described by the original poster with my previous brake system. Had 13" discs with Baer 4-piston calipers up front with 1-piston 13" setup in the back and could never get enough braking power no matter which MC I tried. When I upgraded the fronts to the 14" 6-piston Wilwood setup with BP-10 pads, it was a huge improvement. The BP-10 pads are grippy when they get warmed up, and that's a big contributing factor. My first response was geared towards the actual pedal feeling slightly spongy. I agree with everything Ron wrote, which is why I like the manual setup and the extra control, but I also feel a little 'sponginess' in mine, and I know there's no air in the system and I'm using stainless lines(flex and hard) all around. I read a post somewhere, I think it was a Wilwood rep or someone extremely familiar with Wilwood MC's and manual setups, that stated that you should expect a little more sponginess in a manual setup as you decrease bore size. Part of that 'sponginess' you're perceiving is just extra pedal travel which is expected(and desired by people who want that extra modulation). For me, the feel is not a problem, I was just trying to help the original poster with 'feel' expectations on his setup. (that he could have everything matched up perfectly, high grip pads, no air in the system, and might still have a slight 'spongy' feel). Now, if he needs more actual breaking power beyond just the spongy feel, then Ron's write-up is perfect for resolving that. I'd start with upgrading the pads first. And get some extra rags to wipe the extra brake dust off.

[usa-69z]

ok,, i have now wound up the rear calipers so my emergency brake now works.. I have re bled the system ,,no air in lines that is visible and my brake pedal bottoms out on carpet still. very little resistence.. I have bench bled the master several times and was confident it was done correctly.. I will try one more time ..I can pump them up a bit but even at that the car will not stop under braking. It has to be in the master ? air or could the piston stroke be dodgy? Wilwood lists 1.10 inches .. so how much is sufficient ?- Note -- this camaro has been converted to RHD in Australia and the pedal box is foreign to the car.

[GregWeld]

Originally Posted by usa-69z

ok,, i have now wound up the rear calipers so my emergency brake now works.. I have re bled the system ,,no air in lines that is visible and my brake pedal bottoms out on carpet still. very little resistence.. I have bench bled the master several times and was confident it was done correctly.. I will try one more time ..I can pump them up a bit but even at that the car will not stop under braking. It has to be in the master ? air or could the piston stroke be dodgy? Wilwood lists 1.10 inches .. so how much is sufficient ?- Note -- this camaro has been converted to RHD in Australia and the pedal box is foreign to the car.

You have a BAD master cylinder.... swap it out.

[Sieg]

Originally Posted by GregWeld

You have a BAD master cylinder.... swap it out.

Agreed - It's sounding like a bad seal on the piston. I believe Wilwood has a rebuild kit available.

[Apogee]

Originally Posted by usa-69z

...Note -- this camaro has been converted to RHD in Australia and the pedal box is foreign to the car.

What is your pedal ratio?

Tobin
KORE3

[usa-69z]

Originally Posted by Apogee

What is your pedal ratio?

Tobin
KORE3

6-1 i believe or there abouts Tobin,, it was a standard ratio pedal and i have moved it up (pivot point) approx 3/4 inch.. The brakes were pretty much the same (bottoming out) before ratio change. When i pump them up i get a drag on rotors at best.. Im thinking now that maybe the master rod has damaged the master cyl seals ? pushed in too far ? or ? I will check the stroke today..

[Sieg]

Originally Posted by usa-69z

and i have moved it up (pivot point) approx 3/4 inch..

Up (closer to pivot point) on the pedal shaft reduces the leverage ratio!

[usa-69z]

Originally Posted by Sieg

Up (closer to pivot point) on the pedal shaft reduces the leverage ratio!

no the pivot point is at the top and the rod has moved up 3/4 " from the original position

i just measured im only getting just over 3/4 inch of push from my piston on the master then im hard on the floor... Wilwoods have 1.10" stroke so im underdone..
Now how to increase the stroke ?? i cant lengthen the rod and the pedal is against the stop in 'rest position'..any ideas?