Brake Bleed and lost of air

[btgrande]

I have a ´69 Short Stepside, I installed a comple disc brake kit from ECE (front and rear), and a complete stainless steal brake line kit from inline tubes.
I have properly bench bleed the master cylinder, drilled a new hole on the brake pedal, 1" lower than the original hole, as this was a manual brake before. Checked that the rod length is correct from the pedal. But air is keep coming all the time. There is no leak in the system... What can it be?
Enclosed is pictures of master cylinder and proportion valve.

Regard, Bjorn Tore

[PanelDeland]

OK,I'll give this a shot.When you bled the MC you need a kit that dumps the fluid from the lines back into the reservoir.Once that is flowing with no bubbles,mount the MC and hook up the lines.Then starting from the rear right wheel,have someone pump the brakes and hold.Then release the bleeder and close.Repeat until only fluid is coming out.You will have to do this quite a few times.Start at the furthest wheel from the MC and work your way to the closest.You may still have some air but should be able to pump the brakes and get pedal.Bleed again to get the rest of the air out.Somebody is gonna wear theiur leg out pumping.

Some things to check are
1.Bleeders need to be at top(the hose should hook up at the bottom of the caliper on disc).
2.Don't let the MC go low on fluid at any time after you start bleeding.
3.Keep pressure on the pedal when releasing the air theu the bleeder and until the bleeder is retightened.

If you can find one a pressure or a vacuum bleeder will make it lots quicker.

[midniteblues]

Ive allways had to bleed like paneldeland said and after you get some pedal then go for a short safe ride. seems to me the bouncing of the ride moves airbubbles. rebleed afterward and be good to go. curious if the vertical loops in your line could be trapping air.

[oldschool18]

you would think as small as brake lines are that it wouldnt take a lot of fluid, but when you replace everything it can take some time to get the lines full. do like paneldeland said......i open the bleeder and have someone push the brake down nice and slow and hold it down then close the bleeder and repeat that until i get a steady stream of fluid with no air, once there is fluid with no air then i have them pump up the brakes and hold it down then i open the bleeder when they say the pedal is to the floor and there still holding it down then shut the bleeder. keep checking the MC and keep it full, sometime if you open all the bleeders and take the lid off the MC and let it sit for a long time like over nite sometimes gravity will help you out.

[cdowns]

i always start at the left rear as that is the one furthest away from the master cylinder

i also always clamp the pin on the proportioning valve so fluid will flow to the rear brakes

[jjzepplin]

Midnite blues could be right?? I have seen those loops trap lots of air in Small FORD (I know I said Ford-my bad) Ranger hydraulic clutches. A real mother to get out. Ended up pumping fluid up from the bottom of the line.

[Rob68c10]

To the OP, why did you drill a hole lower for the mounting of the pushrod? I was under the impression that as long as you swap the rod out it would be the same?

[btgrande]

Originally Posted by Rob68c10

To the OP, why did you drill a hole lower for the mounting of the pushrod? I was under the impression that as long as you swap the rod out it would be the same?

Hi, I was told to do it when I talked to Mark at ECE. If not, there would be to much leverage on a power assistant brake.
I have tried all the above methods, but I must have pumped gallons of brake fluid thru the system. And air still bubbles out. Can the proportion valve be the culprit? -maybe I should try to bypass it?

[oldschool18]

i would say just double check every fitting to make sure your not sucking in air somewhere