I put a 8 3/4 in my 67 dart and added after market disc kit. Could not get brakes bled. Tried several time pedal went to the floor.
Replaced master, bench bled, bled and pedal still goes to flood. Manually and power bled and same issue.
Added a proportioning valve to back, bled and same issue.
just added a Tee to front bake line and removed distribution block. Bled and same issue.
Replaced both rear calipers, bled and same problem.
Went through a least a gallon of brake fluid already.
I know there is air somewhere but can't find it.
Any ideas????
Thanks

What brakes did you install, I believe some are bled from the top not the bottom.

It’s not doing anything at all ?
Front nor back are calipers are trying to clamp?
What if you plug the master is there resistance in the pedal?
Not being a smart ass but you do understand that you need to close the bleeder before the pedal is lifted , yes? I have seen people open pump and pour.

Are all your bleeders on the top of the calipers?

MC too small...calipers need more fluid volume than the MC can supply?

I'm guessing you are trying to bleed GM metric calipers with a parking brake.

If so, did you ratchet the parking brake mechanism fist, then unbolt the caliper and reposition it so the bleeder valve is parallel to the ground?


https://www.youtube.com/watch?v=q4_17Gg7tdg

Did you confirm the length of the MC pushrod when you installed the new master? Too long?
Or, the MC is defective?
Perform a MC test.
Look into the MC reservoir, apply the brake.
You should see a small momentary squirt from the compensating port (hole in the bottom farthest forward in the individual reservoir). The squirt of fluid back into the reservoir should be momentary and then stop as you continue to push the pedal towards the floor. If it continues to quirt from the compensating port then the primary cup on the piston is defective.

Thanks to everyone but I believe Cass has it. I never adjusted the parking brake and viewing youtube I will have to adjust this.
I will update as soon as I get back in the garage.

Just some info this kit does have the metric calipers, bleeder is on top and original Master was working with original break set-up.

if it is the gm calipers on top is a relative term.
I could not get them to bleed all the air out till I took them off the mounts and turned them as Cass mentions, to finally get all the air out.
Feets thought a power bleeder would work too and burned a bunch of fluid and still had to unmount them to bleed them finally.

Yep I already took the caliper off and bleed. The only thing I have not done is adjust the parking break.

https://www.youtube.com/watch?v=Nz0vDpE0bbo

watch this one too.
it is in the comments of the one dr. diff gave a link for.

This part sucks under the car.

Thank to all. Videos really helped. Last video was helpful getting piston clocked.
I have BRAKES.

The GM calipers are a pain to get adjusted right but once done they do work good.

So I have this GM rear kit on my 66 coronet, I have bleed the brakes a couple different ways, with a pressure bleeder from the top and with a hand held vacuum bleeder at the bottom. I get fluid from the rear, but not near as much as the fronts. I have also felt like the pedal is softer than it should be for manual brakes. So does the procedure of adjusting the parking brake change how well the rear calipers work?
Do you think it would be beneficially to adjust the parking brakes, and set the calipers upright and try to re-bleed them?
A little more information while I am thinking about it, when I installed the brake kit, it seemed like my rear brakes were not holding properly, the fronts would not move when the pedal was down , but the rear would with a pry bar. I had to adjust the proportioning valve wide open to get the rear brakes to seem like they would hold to the point where they needed to be, so maybe this is some of my issue, or reason i had to do that? I do know my parking brake seem to work as I have tried it in the shop, but I have not been able to make a road voyage yet. Don't want to hijacks the thread but since it is the topic any help would be great.
Matt

as far as i can tell, all rear calipers that have emergency brake cables attached, need the pistons "ratcheted" out to properly bleed the calipers and work as they are supposed to.
failing to do this results in a spongy, low pedal, or non working rear calipers.
the GM [buick, cadillac] and ford [tarus among others] are infamous for this.