I have tried the method you describe before with the factory rotor's and caliper's with the same results of having a soft pedal. I will give it a try with the Wilwood rotor's and caliper's and hope for the best and eliminate air in the master as a possible culprit.

 

If you are using a 1.0" bore MC and not the 1.125" spec I don't see this changing for you.

 

Good call. I have the master that Napa gave me and it is supposed to be for power brakes. I will check that out tonight and verify.

 

another thing you can check is when you apply pressure at the MC for bleeding, see if you can rotate the front wheels. If one of the wheels rotate with 15 PSI at the MC there is a problem of fluid movement to that caliper.

Both front wheels should have similar resistance with 15psi applied at the MC.

Also did you check the clearance of the rod between the MC and the power booster ( Power brakes ) or the brake pedal. There should be 0 slope meaning when you press the brake pedal the MC should also see movement to apply fluid
to the calipers.

 

It is now verified I have the correct power brake master.

[QUOTE=cagotzmann;

Also did you check the clearance of the rod between the MC and the power booster ( Power brakes ) or the brake pedal. There should be 0 slope meaning when you press the brake pedal the MC should also see movement to apply fluid
to the calipers.[/QUOTE]

I have just saw the threaded rod on the booster and wondered if it was out of adjustment. I got the vernier caliper out and worked it out to what I think is spot on.

 

Question: If I have the master off the car and bench bleed with the rear of the master higher up than the front wouldn't that be the same as the method you describe in the link?

 

The problem with bench bleed only it is still possible to get air into the MC since you need to connect the lines. Air always moves to the highest point.

So if you have the MC off still bench bleed, then install on the car.

Then connect a line from the driver side bleed screw and return to the MC, bleed until you don't see air in the line. Then do the same with 1 rear caliper.

Then bleed the MC while on the car. (Raised rear) .

Slowly press the brake pedal , it may press to the floor. You should see 2 possibilities , air bubbles out the bleed holes or fluid being pushed out the bleed holes.

Then pressure bleed the longest brake line to the shortest brake line.

To save brake fluid I would recirculate until you get the pedal feel required. Then I would flush if required.

 

Is this step something new? I have never read this step before, anywhere.

 

This will show how much fluid moves in the front brakes and the rear brakes. If you see very little fluid move then there is something else not working.

Also you will be able to see when you press the brake at what point fluid starts to move ( checks the preload of the brake booster pin ) You should see fluid start to move as soon as you press the brake.

This is similar to bench bleeding a MC but you extend the line from the MC thur a caliper. Saves fluid also.

 

Just gave the brakes a quick bleed yesterday, put the wheels on and lowered it off the stands. Torqued the lugs fired it up for the first time this year, just about to go for test drive and it started to rain again. Oh well there will be some dry days this summer. T

 

So now I have a new complete set of Wilwood D8-4 calipers and Wilwood drilled and slotted rotors along with their braided short lines. I also have a new Napa master cylinder that is correct for my 76 with power brakes. Upon installing the rotors I checked runout on all four and adjusted to within spec using shim stock. After removing the master cylinder to install the new Napa piece I verified the length of the booster pin was adjusted properly using a vernier caliper and math. I bench bled the master, bled the left front caliper then the right rear back into the master to verify I have good flow. Then I lifted the car with the rear high enough to position the bubble in my bullet level toward the windshield and slowly pumped long after no air was visible in either compartment of the master. I repositioned the car to level it all the way around then began the bleeding process with my Motive Power Bleeder. After removing the right rear caliper and putting small pre-cut blocks of wood in between the brake pads I positioned the caliper completely vertical then opened the top outside bleeder a 1/4 turn and bled until no air was visible in my clear tubing, I repeated these steps on the inside top bleeder and continued to the left rear where I did the exact same procedure. Next I bled the right front again starting with the outside top bleeder then the inside. This same procedure was repeated on the left front. My pedal is still soft but I have brakes for now so I'm going to let it go for awhile due to the simple fact that I'm tired of working on this thing. I know some of you will suggest I bleed them again but I estimate I have bled these brakes two dozen times in the past five years even though I have not driven it much and never have I had a good firm pedal. I really wish the car had a low maintenance single piston caliper set up.

 

The pedal should improve as the pads and discs bed into each other.
Give it 50-100 miles to bed in, and then bleed the calipers again.

This would get rid of the last of the micro bubbles that tend to stick between the piston and caliper bore, and places like that.

 

I would press the brake pads inward to force the caliper pistons in as far as they can go. Then use a vise grip to hold them in place, or wedge something between the rotor and the pad to keep the pistons in place. Then "pressure bleed" the lines. Apply about 20psi at the MC to bleed.

This will force any air in the piston bore to be removed. leave the pressure on the MC, remove the wedge / vise grip and make sure with 20PSI @ the MC the pads should push out and return to the normal position.

You will also be able to check if the pads are seating properly by trying to rotate the wheel (front tires) it should difficult to turn with 20 PSI @ the MC.

 

I just installed the Wilwood front and rear brakes with a new Napa master. I have bled the brakes way too much and still have a soft pedal. I will try the raised rear method to get any possible air out of the master. These C3s have a lot of high maintenance issues like this it seems. Using my Motive pressure bleeder works well on my other cars, but on the C3 it barely pushes out bubbles. I guess that should have been a red flag. I just thought maybe I missed the bubbles when I stepped away for a second. At some point I may just bring it in to someone who knows how to deal with the C3s. I only have some much time and patience.

 

That's oddballish. I bled my Wilwoods with a pressure bleeder and they worked from the first time I did. No special elevations or anything; just flat and up in the air. The brake fluid flowed freely also.
Are you saying that the bleeding does NOT flow freely from either the front brakes or the rear brakes?

 

I believe there is air trapped still somewhere in the system. Likely suspects from what I am reading is the master cylinder, due to it not sitting level, and the rear calipers, which also sit at a bad angle. Everything is new with the exception of the proportioning valve. Fluid seems to flow great with the Motive pressure bleeder.