Help New here 74 Brake Bleeding issues

[Theresan4177]

Hi I have a 1974 stingray. My husband is an auto mechanic and we do all our own work on all our vehicles. We recently have done work on my car and cannot get the brakes bled. We replaced the master and proportioning valve, the rubber lines and all 4 calipers. We have bench bled the master and bled the brakes everyway we know possible and still no brakes. There is not a lot of corvettes around here and not really a place to take it that we trust. Any help would be greatly appreciated as I really hate her sitting up on jackstands in the driveway.

[BruceF]

Welcome to the forum

Did you bleed the rears from both bleeder screws? Offhand I don't remember which should be done first. Many people miss this.

I have seen new masters and proportioning valves be bad right out of the box as well. And there could be small leaks around the bleeders themselves.

Here's an article that may help:
https://www.corvettemagazine.com/cor...rake-bleeding/

Moderator's note - moving thread to C1-3 Tech section and clarifying subject.

[Poltergeist]

Normally you start with the bleeder farthest from the master cylinder and work your way to the closest.

[Theresan4177]

We have bled the system manually, starting with the furthest caliper, outside first then inside, and used a vacuum bleeder, still low soft pedal with little brakes. We have also installed a tool in the valve to stop it from shifting during the bleed procedure. Checked several times for leaks, none found. Master was bench bled both off then again on the car. Its diving us nuts.

[Poltergeist]

Like Bruce said the master cylinder could be bad out of the box. Might have to get a replacement and start over.

[Theresan4177]

We are on the 3rd master, picked up a pressure bleeder, still no pedal. Talked to a gm tech, was told to stand the calipers straight up when bleeding, no luck. No leaks, all hoses new, any questionable steel lines replaced, don"t get it.