Soft Brake Pedal - Need Help
 

I am having trouble getting pedal pressure as the pedal almost goes to the floor. I bled the brakes 3-times, took it to a performance shop and had them bleed them and still no improvement. I am getting solid fluid to the calipers with no air bubbles. I clamped off each brake line individually to see if I noticed a change in pedal pressure and still no luck.

Any other suggestions?

Re: Soft Brake Pedal - Need Help (toy350)
 

R U using dot 5? My brakes feel soft but she stops well, been there, bled that, replaced M/C.....believe dot 5 is the culpret.

Re: Soft Brake Pedal - Need Help (toy350)
 

Try changing your break booster. Not a hard job. The break booster gives you pedal preasure, good luck. :flag

Re: Soft Brake Pedal - Need Help (Geoff1340)
 

Hey Geoff1350,

I run Motul 600. You think that could be it?

Hey Road Racer,

Showing my ignorance, does the brake booster only work when the car is running? Meaning, should I have a stiff pedal when the car is off?

Re: Soft Brake Pedal - Need Help (toy350)
 

just to be sure, check your vacuum could have a leak

Re: Soft Brake Pedal - Need Help (toy350)
 

Jeff,

Have a look at the runout on your rotors. The C-3's do have a problem with pedal travel due to slightly warped rotors. It causes the pistons to stand off the rotors farther than normal, hence they have to travel farther to hit the rotor and causes low brake pedals. :D :cheers:

Re: Soft Brake Pedal - Need Help (best_vette_yet)
 

Check these out..... If I understand you the soft peddle is after bleeding and you do not have to run it. So heating up something is not involved.
1. Rotor thickness all the way around. Can not be less than min turning thickness. Even that becomes questionable.
2. Master cylinder bleeding.
3. Boster push rod length or peddle free travel. No more than 3/4" before MC contact.
4. Good sealed vacuum on the booster. What are you pulling on the intake manifold?
5. Bleed in the right squence. RR (inner then outer), LR (inner then outer)
Rt front, LF front.

Re: Soft Brake Pedal - Need Help (best_vette_yet)
 

Have the same problem with my 77. Somewhere I thought I read that the rotors must be turned (machined) on their respective spindles(?).
How would you ever do that?

Re: Soft Brake Pedal - Need Help (mox 77)
 

You first check the rotor thickness with a mic. Check runout with the rotors on the car. Should not exceed .004" or you will start pumping air.

Fronts can be taken off, rivets drilled out and turned if the thickness is sufficient. Consider new ones as they are about $60 each.

Rears need to be turned on the T-arms to take into account bearing runout and shaft wobble. Need to pull the T-arm and send it out for rebuilding at one of the places like Bairs', Van Steel etc.
Once turned they should be good for almost life.