A pressure bleeder will eliminate the air from the system and the need for an assist to pump the brake pedal. Now, if air is trapped in the ABS module, it might not move from it.
However it is worth a try, afterall, how long would bleeding the brakes take on the assembly line?

 

Have a read


https://www.tomorrowstechnician.com/...n-gm-vehicles/

well wasn’t that interesting? Now read post #4 Lucky explains a method he used and had successfully bleed brakes
https://www.chevyhhr.net/forums/www....ad.php?t=33854

 

I've always tightened the bleeder before you hit bottom with the pedal, while the pedal is still moving downward. If the pedal hits bottom, stops moving while the bleeder is still open, air can potentially get in.

 

Nice read. I'm suspect I have air trapped in the ABS module. I'm going to call and chat with a local mechanic since I don't have a scan tool to bleed the module.

Another good read. I can try that method also, with opening the bleeder BEFORE pushing the pedal down. Previously, I opened the bleeder AFTER my assistant pushed it down.

This method bit me in the butt last year when I upgraded to Brembo's and bled the system. I used this approach the first time I bled them. But the pedal was still a little soft. The second time, I had my assistant depress the pedal fully, after which I immediately tightened the bleeder. That attempt was successful.
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Go to Harbor freight and get a vacuum pump (MityVac is one brand). Available elsewhere, but HF has sales and coupons. One man bleeding made easy.

 

You may have a leak. Perhaps an internal leak, such as in the master cylinder.

 

Case closed. I fought with the system and tried to bleed it 5-6x. No dice. I had a local shop cycle the ABS module (and nothing more) to hopefully purge its air. I then brought it home and bled the calipers again. He did it pro bono and warned me it still might not be right, which he was correct about. He said the Tech II mandates a full-blown procedure to cycle the module and purge the calipers with a pressure bleeder in a long sequence of prescribed events. So I took it back to the shop and had them bleed the entire system with the Tech II and a pressure bleeder ($$). Now it is back to normal, thankfully. Done deal. Lesson learned.

 

Awesome! Enjoy the ride!

 

Here is a cost effective pressure bleeder if you are into the DIY stuff. Of course scanner with abs capability helps too.

They work very well
You have to be very gentle with the brake fluid so as not to create microscopic bubbles which will collect into larger ones in your system later on. Brake fluids are bad about that.
Comes in handy for refreshing the fluid every couple years.

 

The Scan II tool is required for proper ABS bleeding of the brake fluid.