Power brake modification is a bit weak

[Stonekij31]

I successfully installed a power brake booster on my 79 Volare with the correct linkage. Bled the system correctly and the brakes feel quite loose. The car will stop, but I have to put the pedal to the floor. Any suggestions?

 

[AMC Diplomat]

Did you bench bleed the master cylinder before installing it?

 

[Ash_Whole]

is the right proportioning valve installed?

 

[OLDIRON]

Do you have a good understanding on adjusting the booster to master push rod?