[LS2 Bad]

I just put some new pads in C6 over the weekend and went to bleed the brakes and spent nearly 2 hours trying to bleed these things, and they are still soft! I'm certain this has got to be something small and just over looked on my end, but I can't seem to figure out what I could have missed, everything is pretty much straight forward.

Have you been in situation like this? What did you end up finding was the cause of air in the system?

Actually was just wondering if the master cylinder could have went? That would cause the brakes to be soft still??

[BBQVETTE]

We have a local repair Shop that specializes in Corvettes. I had a similar problem that I took the car to them for repair. They told me they used a Motive power bleeder.

He told me that they bleed the brakes with the power to the car off and then they do it again with the car ignition on. The guy also told me to be patient with the rear brakes during non-ignition power bleeding.

Sorry, that's all I know. Good luck.

[toobroketoretire]

Originally Posted by LS2 Bad

I just put some new pads in C6 over the weekend and went to bleed the brakes and spent nearly 2 hours trying to bleed these things, and they are still soft! I'm certain this has got to be something small and just over looked on my end, but I can't seem to figure out what I could have missed, everything is pretty much straight forward.

Have you been in situation like this? What did you end up finding was the cause of air in the system?

Actually was just wondering if the master cylinder could have went? That would cause the brakes to be soft still??

When bleeding brakes, it takes VOLUME to push the air out of the calipers. So a brake bleeder is often a big help because it forces the fluid out under pressure.

[wayback]

Not sure why you would need to bleed the brakes just from changing pads. Did you open the bleeders to push the calipers back? Or change the fluid?

I used a block of wood and squeezed the calipers back in. No need to bleed the brakes. System was never opened.

[talon90]

Originally Posted by wayback

Not sure why you would need to bleed the brakes just from changing pads. Did you open the bleeders to push the calipers back? Or change the fluid?

I used a block of wood and squeezed the calipers back in. No need to bleed the brakes. System was never opened.

First, I agree completely with Roger.

Second, are you sure that the technician was following the procedure to bleed CORVETTE brakes? There is a very specific sequence that should be followed because the Corvette uses a split system putting the left front and right rear and right front and left rear on the same hydraulic path to prevent a total failure of either front or rear brakes in the event of a system fault or line damage.

[wayback]

Originally Posted by talon90

First, I agree completely with Roger.

Second, are you sure that the technician was following the procedure to bleed CORVETTE brakes? There is a very specific sequence that should be followed because the Corvette uses a split system putting the left front and right rear and right front and left rear on the same hydraulic path to prevent a total failure of either front or rear brakes in the event of a system fault or line damage.

Paul, I learn something new every time you post. Did not know that is how the brakes were split. Thanks

btw what is the correct sequence for CORVETTE brakes?RR, LF, LR,RF?

[smokinsilvervette]

To be honest, as long as you start with the furthest bleeder and work your way around, you will be fine. Generally the furthest bleeder from the master cylinder is the left rear.

Since ABS has been instituted, if you are not bleeding the system with a Tech 2, I have found that a good gravity bleed followed by someone assisting the old fashioned way, pressing on the pedal, WHILE THE CAR IS RUNNING, will purge the system of air.

[talon90]

Originally Posted by wayback

Paul, I learn something new every time you post. Did not know that is how the brakes were split. Thanks

btw what is the correct sequence for CORVETTE brakes?RR, LF, LR,RF?

Hydraulic Brake System Bleeding Manual
Caution
Refer to Brake Fluid Irritant Caution in Cautions and Notices.


Notice
When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. The use of any type of fluid other than the recommended type of brake fluid, may cause contamination which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.


Notice
Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Cautions and Notices.

Place a clean shop cloth beneath the brake master cylinder to prevent brake fluid spills.
With the ignition OFF and the brakes cool, apply the brakes 3-5 times, or until the brake pedal effort increases significantly, in order to deplete the brake booster power reserve.
If you have performed a brake master cylinder bench bleeding on this vehicle, or if you disconnected the brake pipes from the master cylinder, you must perform the following steps:
Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary, add Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal.
With the rear brake pipe installed securely to the master cylinder, loosen and separate the front brake pipe from the front port of the brake master cylinder.
Allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder.
Reconnect the brake pipe to the master cylinder port and tighten securely.
Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
Loosen the same brake pipe to purge air from the open port of the master cylinder.
Tighten the brake pipe, then have the assistant slowly release the brake pedal.
Wait 15 seconds, then repeat steps 3.3-3.7 until all air is purged from the same port of the master cylinder.
With the front brake pipe installed securely to the master cylinder, after all air has been purged from the front port of the master cylinder, loosen and separate the rear brake pipe from the master cylinder, then repeat steps 3.3-3.8.
After completing the final master cylinder port bleeding procedure, ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.
Fill the brake master cylinder reservoir with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. Ensure that the brake master cylinder reservoir remains at least half-full during this bleeding procedure. Add fluid as needed to maintain the proper level. Clean the outside of the reservoir on and around the reservoir cap prior to removing the cap and diaphragm.
Install a proper box-end wrench onto the RIGHT REAR wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve.
Submerge the open end of the transparent hose into a transparent container partially filled with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
Loosen the bleeder valve to purge air from the wheel hydraulic circuit.
Tighten the bleeder valve, then have the assistant slowly release the brake pedal.
Wait 15 seconds, then repeat steps 8-10 until all air is purged from the same wheel hydraulic circuit.
With the right rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the right rear hydraulic circuit, install a proper box-end wrench onto the LEFT FRONT wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
With the left front wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left front hydraulic circuit, install a proper box-end wrench onto the LEFT REAR wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
With the left rear wheel hydraulic circuit bleeder valve tightened securely, after all air has been purged from the left rear hydraulic circuit, install a proper box-end wrench onto the RIGHT FRONT wheel hydraulic circuit bleeder valve.
Install a transparent hose over the end of the bleeder valve, then repeat steps 7-11.
After completing the final wheel hydraulic circuit bleeding procedure, ensure that each of the 4 wheel hydraulic circuit bleeder valves are properly tightened.
Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
Slowly depress and release the brake pedal. Observe the feel of the brake pedal.

Important
If it is determined that air was induced into the system upstream of the ABS modulator prior to servicing, the ABS Automated Bleed Procedure must be performed.


If the brake pedal feels spongy, repeat the bleeding procedure again. If the brake pedal still feels spongy after repeating the bleeding procedure, perform the following steps:
Inspect the brake system for external leaks. Refer to Brake System External Leak Inspection .
Pressure bleed the hydraulic brake system in order to purge any air that may still be trapped in the system.
Turn the ignition key ON, with the engine OFF. Check to see if the brake system warning lamp remains illuminated.

Important
DO NOT allow the vehicle to be driven until it is diagnosed and repaired.


If the brake system warning lamp remains illuminated, refer to Symptoms - Hydraulic Brakes .