Brakes???

[91lxguy]

Anyone in the N. FTW area that is good with brakes? I am trying to determine if it is my master cylinder or my booster. I have bled the system correctly I think... If anyone has some suggestions or can help out, PM me... it is greatly appreciated.

Thanks in advance!

[Trick Pony]

Is the pedal soft or hard? Usually if the booster is bad your pedal will be really stiff. If it's really soft, try gravity bleeding it. That's the only way I was able to get all the air out of mine. If it's soft and you're sure there is no air in the system then it's probably your m/c. I had to replace the one on my '85 a few weeks ago because of this.

[91lxguy]

Before I did the brake upgrade, the pedal travel was not far at all. Seemed like only an inch or so. It would stop by the time the pedal would reach the end of its travel.

Now, I feel like I have the same issue, just a much softer pedal.

Does that make sense?

[91lxguy]

Before I did the brake upgrade, the pedal travel was not far at all. Seemed like only an inch or so. It would stop by the time the pedal would reach the end of its travel.

Now, I feel like I have the same issue, just a much softer pedal.

Also, I used the Motive Products brake bleeder kit. It attaches to the master cylinder cap and you pump it up to about 10-15psi, and then you just walk around and bleed the brakes until you get that steady stream and no bubbles... doing this, I noticed that when I pressed down on the pedal air bubbles came up from the reservoir...

Does that make sense? Could the master cylinder need to be bench bled again? or do you think it could just be bad all together?

[JimD]

Yep gravity bleed tilll clean fluid comes out then bleed again with someone pumping the pedal. What u mean by upgrade?

[Trick Pony]

Depending on what you upgraded and what combo as far as m/c, booster, and brakes you are running, that can cause a soft pedal as well. What's your setup?

[91lxguy]

Depending on what you upgraded and what combo as far as m/c, booster, and brakes you are running, that can cause a soft pedal as well. What's your setup?

Cobra Calipers front and rear, proportioning valve, stock master cylinder and booster as far as I know. I changed out the Calipers in the front and added SS brake lines in the front. Now everything is worse... I bought a pressure bleeder to help me bleed my brakes, but either I didnt do it right or I have something else wrong... just not that savy with brakes.

[Your Name Here]

Dont use the vacula. Gravity bled for a while then old school pump/hold/bleed with someone.

[kingjason]

The little 4.99 self bleeder kit from harbor freight works wonders. My dad was having hell with his street rod till I gave him one. Took him less then ten minutes to get a perfect pedal. It is the one where you plug it in at the caliper and crack the bleeder and just pump away.

[kingjason]

The little 4.99 self bleeder kit from harbor freight works wonders. My dad was having hell with his street rod till I gave him one. Took him less then ten minutes to get a perfect pedal. It is the one where you plug it in at the caliper and crack the bleeder and just pump away.

Ok I have to go back and argue with my own adivice. Today I swapped my M/C and all my leaking calipers on my Vette and F me it took me for ever to bleed them bastards. The lille kit works bad ass once you get fluid moving but with a non bench bled MC and empty lines and calipers you need something to get the ball rolling. I ended up using a vacuum pump I had and pulling fluid to the rear calipers. Once I got fluid to the rear the little self bleeder worked great but it took me about 5 rounds to get all the air out. LOL I will probably bleed them again in a week after they have settled out some but i do have good brakes.

[Trick Pony]

Cobra Calipers front and rear, proportioning valve, stock master cylinder and booster as far as I know. I changed out the Calipers in the front and added SS brake lines in the front. Now everything is worse... I bought a pressure bleeder to help me bleed my brakes, but either I didnt do it right or I have something else wrong... just not that savy with brakes.

Stock master cylinder is definitely not ideal for that setup since it wasn't designed for discs in the rear. Not sure if that is contributing to your problem though. Here is some info on 4 wheel disc brake master cylinders:
84-86 SVO - 1 1/8" bore, old style aluminum reservoir unit. no low fluid sensor. Works best with the larger caddy or Lincoln rear calipers or the front SVO 73mm calipers.
93 Cobra - 1.00" bore Best MC but also expensive.
94-98 V6/GT - 1 1/16" bore, stock plug in for the low fluid sensor. Better compromise for most everything but the Cobra or Brembo brakes..
94-95 Cobra - 15/16" bore, stock plug in for low fluid sensor. Ports are reversed thread sizes from V6/GT. Best for Cobra or Brembo brakes.
99 V6 - 1.00" bore. Similar to 93 Cobra unit.

Try the gravity bleeding first. I ended up doing mine for like an hour on each corner and the pedal feel was much improved. Just make sure you don't let the m/c run dry.