Bleeding Front Brakes


Hoping to get some clarity.

I've read through a bunch of posts, but I seem to be having an issues bleeding my front brakes.
I have powermaster setup with the acc ball, I pumped the brakes 10 times to get all the brake fluid out of the ball. I bled the rear (had to replace rear cylinder assembly and hard lines, not fun). Got good clean steady fluid coming out of them. Moved to passenger front, seemed to trickle out at first, but i got nothing now. Opened the driver's front bleeder, same thing, no fluid.
I am using a handheld vacuum gun to try and pull the fluid through, but no luck.
My question is, do i flush the front brakes with the acc ball empty or do i need to power it car on and get the fluid sucked back into the ball and bleed them from there?
This is my first time bleeding the brakes on the Buick, I've done it on older gm A-bodies/mustangs with no issues.
Thanks in advance for any help, this the last thing i need to do before i can get her back on the road for fall.
you are using the bleeder tool gizmo on the proportioning valve to keep the slider centered so fluid is able to be drawn thru any of the brake lines?

without it, the slider moves in the direction of fluid flow, restricting flow thinking a brake line is severed. this is to keep brake fluid from draining in the event of brake line failure so you still retain some braking ability.

the gizmo tool takes the place of the idiot light switch on the prop valve. link to tool on ebay below...

@Anthony P thanks for the tip. I am not using that blender to gizmo, didn’t knows I needed to in order to bleed the front brakes. Don’t believe I ever read about it when I searched the threads.
So I just put it in place where the light is, bleed it then pull the gizmo and out the light back on?
usually one sees the lack of getting any fluid when starting at the right rear, furthest away. some of the ebay sellers of the brass prop valve include a version of the gizmo tool - usually the plastic(nylon) one.

Yes, prep for brake bleeding like you did. the tool replaces the brake light switch for the bleeding process. some sellers of the tool and the prop valve show a cut away view of the prop valve illustrating how the metering valve can slide and block fluid flow.

the thread below discusses what you encountered and the use of the tool.


Thanks to the input it looks like I'm going to be able bleed all four brakes tonight. I purchased that gizmo off ebay that was mentioned. I read somewhere that if you step on the brake pedal a few times it will re-center the piston in the prop valve, which I did after i pulled the brake sensor and put in the gizmo with no issues. Opened the bleeders in the front to see if i could get fluid moving and had the wife press the brake pedal and I got fluid coming out of the front two calipers. i let the reservoir get low, too low, close to empty so i picked up a bench bleeding kit and bled the master cylinder last night, got all the air out. I'll bleed all four corner properly tonight in the correct order.

One step closer to getting her back on the road.

Thanks again for the help, i'm sure i'll be on here again asking stuff (i'm actually about to post a question about exhaust leaks and smoke tests).