Technical Im at a loss. Need some help bleeding brakes on 62 imperial with power/vacuum brakes

So i just bought a 1962 imperial off a fellow HAMB'er. Car is awesome and have some miles on her. I noticed the other day the left rear axle seal was leaking so i ordered in some seals and watch a YouTube video for the details. Now this isn't my first rodeo when i comes to brakes. Originally i had only removed the left rear wheel cylinder, replaced the seal, repacked bearing and put it all back together. No big deal..hook up rear wheel cylinder crack the bleeder a few time and back in the road right? Nope...tried adjusting the brakes and bleeding for a couple of hrs and still no pedal. I did notice the wheel cylinders were slightly wet under the rubber end so.....new cylinders and shoes a few days later and 2 more hrs of bleeding and still no pedal.

This car has drums all the way around and a vacuum booster thing that the MC bolts to. Now im pretty sure everything is in good working order because the previous owner replaced everything a few yrs b4 i got it. Ive tried bleeding with the car running, without it running and still no pedal.

What am i missing?

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when you took the wheel cylinder off did you let the master go dry ??? if so it needs to be bench bled then the system bleed if was undone for a 1/2 hour often it will empty the master and system , bleed after bench bleeding starting at the right rear then left rear then right front then left front . do not try to bench bleed the master on the car often they are at a angle and trap air in the ends of the bore and you can never get it out and a little bubble is all it needs to be mushy . ( air compresses liquids do not )

 

X2


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Sometimes with drum brakes you have to adjust the brake shoes because the wheel cylinders need filling and push the linings out to the drum before you see any pressure. Most times a push on the pedal won't get the job done. In effect you might be just moving the wheel cylinder piston back and forth in the bore and it isn't contacting anything to create the pressure. You 'pump' up the pedal, crack the bleeder but the wheel cylinder piston hasn't contacted anything so there's no spurt, you close the bleeder and your assistant releases the brake pedal to let the wheel cylinder piston return. You can do that over and over.
A vacuum type bleeder is handy in situations like that.

 

Vacuum bleeder recommended, can confirm. If you don't have one some parts stores lend or rent tools.

 

No didn't let MC go dry. At first just unhooked one side.....little bit dribbled out...hooked back up and a few pumps and cracks of the bleeder and i had fluid. After a few hrs still had good fluid but no pedal. I then replaced both rear wheel cylinders and shoes...got them all adjusted and bled with good fluid but still no pedal.

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heres a question how old is the master??? maybe it went south , it can push liquid but if the cup is worn or torn it will not develop the pressure to push against the springs and its bypassing internally .

 

this may be a silly question but did you bleed the fronts as well? also my 61 Dodge Seneca has two wheel cylinders on each side in the front, your car may be the same.

 

Never touched the front far as any repair. The master cylinder and all the other brake parts are only a few yrs old

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I did go back a crack the front bleeders just to check and they were all good

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What i cant understand is the brakes worked just fine before so it cant be anything to complicated or I wouldn't think any failure in the front or with the MC