No pressure in break lines HELP

So i have a 64 impala on airbags. When i would lay the rear end it started smashing the rear break line. So i changed it out. I bled the breaks but the pedal would still be soft. So i bled them again. By the 3rd time bledding it, the pedal had no pressure. The pedal goes all the way to the floor. I had my wife pump the breaks with the master cylinder cap off and i noticed bubbles. I checked all lines and bleeder nipples for leaks but could not find a leak. I opened the furthest wheel nipple and had her pump the breaks and a little fluid came out, not much, then it stopped. I looked at the master cylinder and most fluid that i put in was still there. I dont think the master cylinder is sending enough pressure to the lines. Could this be a bad master cylinder? I dont notice any fluid leaks anywhere. Oh and this is a single wheel cylinder. Help thanks

 

did You bleed all 4 lines, or just the rears?

 

all 4 wheels

 

there is no more pressure build up anymore for me to bleed them. It seems like the fluid is not traveling in the lines.

 

okay try this.
first things first-
if the car is sitting at a funky angle, it may not bleed right.

start by pinching off the 3 soft lines. try the pedal- it should be rock hard or damn near to it, with no pressure bleed off.
one by one, remove the clamps , and check the pressure each time. the pedal will drop a bit with each clamp, so don't worry if it does.

if You pull the rear one first, and it floorboards, the problem is air in the line, or possibly issues with the wheel cylinders. (or adjustment.)

what You are describing sound like to me the master went dry and has a crapload of air trapped in it. it may be neccecary to re-bleed the master.


but-if all was well before You replaced the hose, the chances of something else breaking during it's repair is VERY SMALL.

start with the master- re bleed it, the re-connect the hard line, and work back to front, farthest to closest.

 

if the master cylinder is 'old', it may have 'junk' in it, and when the pedal hit the floor, the rubber cups in the master may have gone over a rust ridge/sludge and hurt the rubber cup that moves in the bore. when fluid did come out, how'd it look? clean, or coffee colored?

 

So i bled the master cylinder and added more fluid. i opened the last blrrder valve and had me wife pump the breaks. Fluid came out with pressure. At first i put my finger in the master cylinder cup and pulled out alot of sludge so i cleaned the master cylinder hand had my wife pump all the old fluid through the lines. It now comes out clear. The weirdest thing is when i open the bleeder valve on the furthest wheel and have her pump the breaks, fluid pumps out but when i close the bleede valve and pump the breaks, no pressure on the pedal. If it was the master cylinder would it still pump fluid through the lines?

 

You could still have a bad wheel cylinder at that last wheel. Since you do have issues with crud in the system, I'd replace all 4 wheel cylinders first and also the master. You may consider going to a dual master system for the added safety it'll give.

Bob

 

You may already be an expert at bleeding brakes but it sounds like you are saying you are opening the bleeder then pumping the brakes, that is the wrong way to do it if that is what you are doing.

1. first somebody (your wife) pumps them up then holds the pedal down holding the pressure.
2. you loosen the bleeder letting the air escape,her pedal will go down (if she has any pressure on the first pump/hold)but she still holds it down till you tighten the bleeder back (do not pump with bleeder loosened/open)
3.after you tighten tell her to pump again and hold
4. repeat this process till you have a steady stream of fluid coming out of the bleeder then close it off and go to the next one and repeat.

 

then there's the old "while you're in there"... I would take bobss396's advice AND change out the rubber brake hoses.

I had the same problem in an old Harley. I changed out everything TWICE, still no go. I deployed oversears, came back with a fresh mind. Tore it down, put it back together, and it worked instantly. Sometimes ya jsut gotta take a breather...

 

any brakes yet?

 

No, i took a break. I was too fustrated. Im going to change the master cylinder soon.

 

........so I guess this means you were bleeding them correctly?

 

Yes , I bled them correctly but for some reason I lost all pressure.