Brake bleeding, Nothing but air from rear brakes Options

[Medtner3]

Just rebuilt my rear calipers with seals from PMB Performance. Using a vacuum brake bleeder I started with the right rear caliper lower bleeder screw ( I have two screws) and initially pulled about an inch of brake fluid with lots of bubbles and then zip. I get zero brake fluid now.

What could cause this? I have no signs of any leaks and the brakes were not bad before I rebuilt the calipers. I read somewhere that I might need to bleed the proportioning valve or even pump into the caliper some brake fluid through the top bleeder ?

I ordered a Motive pressure bleeder which arrives in a few days

[davep]

On a caliper with two bleed nipples, the top is the bleed, and the bottom is a drain; only bleed with the top nipple. Air bubbles rise you know.
When bleeding the system, keep checking the reservoir to be sure it is full by removing the cap and looking down inside. The reservoir is divided by a half barrier into front & rear so an external glance may not reveal that the other half is empty. If a half does empty, then you will have to do a long bleed to ensure any air introduced at the reservoir is removed.
Pedal bleeding ensures that high pressure is able to be achieved, and it also crushes bubbles and helps them move through the system; keeping them from being trapped within things like the pressure regulator. So I like to finish a bleed with pedal bleeding after using either a vacuum bleed or an air pressure bleed method.

[Medtner3]

On a caliper with two bleed nipples, the top is the bleed, and the bottom is a drain; only bleed with the top nipple. Air bubbles rise you know.
When bleeding the system, keep checking the reservoir to be sure it is full by removing the cap and looking down inside. The reservoir is divided by a half barrier into front & rear so an external glance may not reveal that the other half is empty. If a half does empty, then you will have to do a long bleed to ensure any air introduced at the reservoir is removed.
Pedal bleeding ensures that high pressure is able to be achieved, and it also crushes bubbles and helps them move through the system; keeping them from being trapped within things like the pressure regulator. So I like to finish a bleed with pedal bleeding after using either a vacuum bleed or an air pressure bleed method.

Okay the first problem was my master went dry because it was so discolored from ATE super blue that I thought it had fluid. How do I bleed now .. do I need to bleed the master?

[iankarr]

On a caliper with two bleed nipples, the top is the bleed, and the bottom is a drain; only bleed with the top nipple. Air bubbles rise you know.
When bleeding the system, keep checking the reservoir to be sure it is full by removing the cap and looking down inside. The reservoir is divided by a half barrier into front & rear so an external glance may not reveal that the other half is empty. If a half does empty, then you will have to do a long bleed to ensure any air introduced at the reservoir is removed.
Pedal bleeding ensures that high pressure is able to be achieved, and it also crushes bubbles and helps them move through the system; keeping them from being trapped within things like the pressure regulator. So I like to finish a bleed with pedal bleeding after using either a vacuum bleed or an air pressure bleed method.

Okay the first problem was my master went dry because it was so discolored from ATE super blue that I thought it had fluid. How do I bleed now .. do I need to bleed the master?

I would. Since it's gone dry, i'd just start from scratch...

– Bleed the master (in the car is fine...see video link above). Use pedal only...and put a block or something down to make sure you don't hyper-extend the pedal and damage the seals inside the MC). When no bubbles are coming through...

– Put a quart of fluid in the motive, hook it up and pressurize to 5-10 PSI. Use a rubber mallet to rap on the caliper and dislodge air bubbles while bleeding.

– Bleed from the top screws LR, RR, RF, LF.

– Finish with a pedal bleed all the way around.

If you don't have a firm pedal, do it again until you do. If it's firm enough to drive, but not perfect, that's kind of typical. Just carefully drive it on a bumpy road for a bit, then bleed again.

Good luck and be safe!

[Medtner3]

On a caliper with two bleed nipples, the top is the bleed, and the bottom is a drain; only bleed with the top nipple. Air bubbles rise you know.
When bleeding the system, keep checking the reservoir to be sure it is full by removing the cap and looking down inside. The reservoir is divided by a half barrier into front & rear so an external glance may not reveal that the other half is empty. If a half does empty, then you will have to do a long bleed to ensure any air introduced at the reservoir is removed.
Pedal bleeding ensures that high pressure is able to be achieved, and it also crushes bubbles and helps them move through the system; keeping them from being trapped within things like the pressure regulator. So I like to finish a bleed with pedal bleeding after using either a vacuum bleed or an air pressure bleed method.

Okay the first problem was my master went dry because it was so discolored from ATE super blue that I thought it had fluid. How do I bleed now .. do I need to bleed the master?

I would. Since it's gone dry, i'd just start from scratch...

– Bleed the master (in the car is fine...see video link above). Use pedal only...and put a block or something down to make sure you don't hyper-extend the pedal and damage the seals inside the MC). When no bubbles are coming through...

– Put a quart of fluid in the motive, hook it up and pressurize to 5-10 PSI. Use a rubber mallet to rap on the caliper and dislodge air bubbles while bleeding.

– Bleed from the top screws LR, RR, RF, LF.

– Finish with a pedal bleed all the way around.

If you don't have a firm pedal, do it again until you do. If it's firm enough to drive, but not perfect, that's kind of typical. Just carefully drive it on a bumpy road for a bit, then bleed again.

Good luck and be safe!

I bled the Master using your video as a guide. Then I bled with the Motive pressure bleeder and very few air bubbles came out. My pedal is firm but not hard. I have not pedal bled yet. I was thinking test drive around then bleed again with the Motive pressure bleeder. It only pressurizes to 5-6 psi I wonder if that is 914 specific or whether mine is defective although seemed to work

[Olympic 914]

It only pressurizes to 5-6 psi I wonder if that is 914 specific or whether mine is defective although seemed to work

Are you pressurizing the Motive bottle before opening the bleeder screw? or opening the screw then pumping the Motive handle.

I usually pump up to 7-10 lbs then open the bleeder.

The reason you should not pump it to more than 10 lbs is that the lines from the reservoir to the master are attached with hose clamps on rubber hoses and can blow off under high pressure.

[Medtner3]

It only pressurizes to 5-6 psi I wonder if that is 914 specific or whether mine is defective although seemed to work

Are you pressurizing the Motive bottle before opening the bleeder screw? or opening the screw then pumping the Motive handle.

I usually pump up to 7-10 lbs then open the bleeder.

The reason you should not pump it to more than 10 lbs is that the lines from the reservoir to the master are attached with hose clamps on rubber hoses and can blow off under high pressure.

I have the bleeders closed and it goes to about 6 psi have not tied to pump it much higher it stalls there