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whytry
03-09-2005, 10:34 AM
Hey guys, I drove my car around for a little while today, and the brake pedal goes all the way to the floor, almost literally. I can barely shove my foot under the pedal when it hit the brakes, not hard either under normal driving. I found myself rolling past the limit line at almost every light.... What can dramatically cause this to happen? Here is what I have on the car:

SSBC stock front disc brake conversion and stock rear drums. I know with my motor I should get bigger brakes, I am working on a couple of different things at once. Does the brake fluid matter? I am just using the stuff from Kragens.... The car is not powered brakes, never had them, it was an original 6 cyl car with 4 wheel drums. I changed the master cylinder when I went to front disc and have a proportioning valve as well... Any suggestions?

Oh yeah, the pads only have 3k miles on them....

Thanks,
Brad

fuzzyonion
03-09-2005, 11:54 AM
If it happened suddenly, there could be a leak in a line, or the master crapped out on you. How's the fluid level?

Brake fluid matters in that you should get a DOT approved fluid rated at a temperature over what your brakes will be seeing. DOT 3 or 4 on the street is fine.

Fluids also have different rates of moisture absorption and corrosion resistance degradation. DOTs 3 and 4 should be flushed about every 3-4 years, others may specify more frequent flushing.

Also do not mix silicone and glycol based fluids. Synthetic is not the same as silicone. Synth is still glycol based and can be mixed with non-synth, though it lowers its effectiveness.

Basically, unless fluid is leaking or boiling (or dot5 frothing) it cant really cause a low pedal.

whytry
03-09-2005, 01:18 PM
The pedal has always been low ever since I changed to disc's upfront. But now it is really low.... Is there something I should do to raise the pedal up after I solve this problem? So it won't happen again?

fuzzyonion
03-09-2005, 04:25 PM
Just make sure the master is well bench bled, the rear drums are adjusted properly, the system is fully bled, the pushrod is properly matched and adjusted, and the proper sized master is used, and you should have a good pedal, assuming everything else is fine.

I read about people using a 1" master with the single piston calipers on the 1stgen and liking it. To me, that would be a little low. A 1" is more suited to the pedal ratio of the second gen cars, or the smaller 4pot calipers of the 67-68 cars. The proper master should be 1 1/16 - 1 1/8 IMO.

SSBC provides a 1" deep hole master with all manual brakes, regardless of application.