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Installed a power front disc system on 72 mustang. New front brakes, new booster and m/c, new brake lines. I have bled the brakes several times and I still have no brake pedal. The brakes work, meaning I can drive the car a stop it, but there is no brake pedal there. I replaced the new m/c with a different one and bled the brakes and still no pedal. Any ideas? Bad power booster? Air lock in the brake lines? I am taking the vacuum line from the back of the carb to the booster, but I don't think that is the cause.
 

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Sounds like a bad booster or the booster is not getting good vacuum. I would tap into the intake manifold for a vacuum source rather than the carb. If that doesn't help I would replace the booster.
 

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You say no brake pedal. You say you can stop so must have some pedal, right?
Now does pedal go low but firm or low and mushy? Did you check the pushrod length?
Benchbleed the master? Is very high force needed to stop. With working booster only a light touch is needed.
 

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The booster is not involved with brake fluid so should not affect pedal height. The push rod needs to be set at the correct length to get proper pedal height.

The check valve on the booster must be working or the booster won't work without engine racing.
 

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Are you sure the calipers are on the right side? I had the same problem once on my jeep, and after buying a new MC, and brake hoses, in the end, I hav the calipers on the wrong side leaving an air pocket above the bleeder screw. Stupid me!
 

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Installed a power front disc system on 72 mustang. New front brakes, new booster and m/c, new brake lines. I have bled the brakes several times and I still have no brake pedal. The brakes work, meaning I can drive the car a stop it, but there is no brake pedal there. I replaced the new m/c with a different one and bled the brakes and still no pedal. Any ideas? Bad power booster? Air lock in the brake lines? I am taking the vacuum line from the back of the carb to the booster, but I don't think that is the cause.
Did you convert from manual brakes? the pedals are different, pushrod attaches in a different spot on the power brake pedal
 

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Discussion Starter #7
It was an original p/b car but someone had removed all of the front disc brakes so..........I bought a p/b pedal, a p/b distribution block, spindles, calipers, etc. I did bench bleed the m/c. Yes, I do have a little pedal (just enough to push hard and stop at the bottom of the pedal travel). It is mushey all the way to the floor. The pedal does return to about the right height. The only thing I didn't change was the pedal support (the big heavy steel thing under the dash, but I think that is the same for both). Everything bolted up correctly. Maybe I should replace the booster. Thanks for all of the help.
 

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You still have air in the system. Do you have a proportioning valve (cylindrical brass item in line with the rear brakes)? It could need to be rebuilt. Also, has your distribution valve been rebuilt?
 
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