C3 Brakes

[Greg louis]

Love my 75 vette; hate the brakes. Have to bleed every 400-500 miles.

 

[bill81vette]

So what are you selling????

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[bill81vette]

Or looking to purchase???

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[Greg louis]

3c brakes

I screwed up. I should have put the question in tech support and not in the sales section. My mistake.

 

[bill81vette]

I'll move it for you.

 

[bill81vette]

Ok, somewhere you are getting air into you brake system.
do you have to pump the brakes when you go to stop???
lets start there.

 

[Hib Halverson]

Love my 75 vette; hate the brakes. Have to bleed every 400-500 miles.

Overhaul the brakes. Most reman calipers these days are stainless-steel sleeved which eliminates the corrosion proboem that causes air ingestion.

There's a couple of articles here on the CAC about C2/C3 disc brake service. Click here and here.

 

[frank_nesta]

Rotor Runout

Rotor runout is another cause for air being sucked into the calipers. I believe runout should not be more that .005".

 

[Antz81]

Rotor runout is another cause for air being sucked into the calipers. I believe runout should not be more that .005".

IIRC Service manual says no more than .008" but most people like to keep it below .003"

 

[UKVETTEHEAD]

Brakes..

Love my 75 vette; hate the brakes. Have to bleed every 400-500 miles.

You may have corrosion on the bores of the callipers which is preventing the seals doing their job. You may need to update with the stainless steel inserts. or swap out the callipers for newer ones.
Air is getting in through the seals somehow, they are only good at sealing on the pressure side . When you carry out the bleeding are the back ones more difficult than the front? If so, bleed both halves of each caliber at the same time . Good luck.

 

[frank_nesta]

When you carry out the bleeding are the back ones more difficult than the front? If so, bleed both halves of each caliber at the same time . Good luck.[/QUOTE]

I have never heard of that. How is this done? Do you run 2 separate bleeder hoses? Please explain.

 

[UKVETTEHEAD]

When you carry out the bleeding are the back ones more difficult than the front? If so, bleed both halves of each caliber at the same time . Good luck.

I have never heard of that. How is this done? Do you run 2 separate bleeder hoses? Please explain.[/QUOTE]

Yes , you need two bleed hoses connected to each bleed nipple on the caliber halves. With someone on the brake pedal , open each bleed nipple in turn, close off with the pedal on the floor. repeat until all the air is out and them move across to the other rear wheel . do the same before moving to the front wheels. The front are a shorter pipe run and should be easier. If you are working alone a pressure bleed may work but you need the kit for this. I would advise again using a vacumn at the nipples as this can pull air in through the lip seals and you are back to square one. If you still have problems then the callipers or the master cylinder will need to be looked at.

Cheers
UKVETTEHEAD

 

[frank_nesta]

I have never heard of that. How is this done? Do you run 2 separate bleeder hoses? Please explain.

Yes , you need two bleed hoses connected to each bleed nipple on the caliber halves. With someone on the brake pedal , open each bleed nipple in turn, close off with the pedal on the floor. repeat until all the air is out and them move across to the other rear wheel . do the same before moving to the front wheels. The front are a shorter pipe run and should be easier. If you are working alone a pressure bleed may work but you need the kit for this. I would advise again using a vacumn at the nipples as this can pull air in through the lip seals and you are back to square one. If you still have problems then the callipers or the master cylinder will need to be looked at.

Cheers
UKVETTEHEAD[/QUOTE]

Thanks, I will try that the next time I need to bleed the brakes.

 

[Hib Halverson]

Bleeding both halves of a rear caliper at the same time is not a requirement.

When doing the rears. First, I get the back of the car up in the air. I do and right inside half then its outside half. Then I move over to the left inside and then the left outside.

There's a couple of articles here on the CAC about C2/C3 disc brake service. Click here and here.