1964 power brake conversion

[Stinktooth]

First off I have a fairly new set of small bolt pattern wheels I wanted to keep. So I found a set of 1965 small bolt pattern rotors and A arms and calipers (two piston type) off a barracuda at a wrecking yard. Cleaned up everything replaced bushings and brake cylinders rebuilt. Then I thought it would be ok to buy a ebay brake booster and bracket. Well I have no power assist at all. Pulling almost 15 on the vacuum guage and it doesn't even lift the pedal after i depress it. The motor still has its solid lifters and the cam is just a tiny bit more aggressive then the commando factory cam. Is there a easy way to create stronger vacuum to test the booster? Here is a pic of the booster in the car. http://i1376.photobucket.com/albums/ah28/stinktooth/brake booster_zpslywnkxp3.jpg

Thanks in advance.

 

[BillGrissom]

Sounds like you have the 4-piston Kelsey-Hayes calipers and rotors. 15"Hg "should work". An easy way to get stronger vacuum to test is to connect a hose from the intake of another car where the power brakes work fine. The Honda in you photos should work. Before that, remove the vacuum line and cover it. If the engine idles slower like that, your booster has a leak. Usually, you would hear that inside the cabin as a hissing. If truly stumped, you can unbolt the MC from the booster and slide it forward. As a helper pushes the brake pedal by hand, see if the booster's output rod follows the motion smoothly. I have tested boosters like that, uninstalled, connected to the vacuum from a convenient car.

 

[Stinktooth]

Sounds like you have the 4-piston Kelsey-Hayes calipers and rotors. 15"Hg "should work". An easy way to get stronger vacuum to test is to connect a hose from the intake of another car where the power brakes work fine. The Honda in you photos should work. Before that, remove the vacuum line and cover it. If the engine idles slower like that, your booster has a leak. Usually, you would hear that inside the cabin as a hissing. If truly stumped, you can unbolt the MC from the booster and slide it forward. As a helper pushes the brake pedal by hand, see if the booster's output rod follows the motion smoothly. I have tested boosters like that, uninstalled, connected to the vacuum from a convenient car.

After much experimenting with the master off the booster and on I tried plugging the to lines coming from the master and found the pedal was still dropping. I decided to bench bleed the master one last time hoping air was stuck in it and it seems that was the problem! I did not use the provided tubes to squirt the fluid back in the master I held a bucket in front of the outlets and pushed very hard on the piston. I did not notice air but when I reinstalled it on the booster Problem Solved.Thank you for your help I appreciate the effort and learned my lesson.

 

[BillGrissom]

Yes, I often go 50 strokes of an MC before getting all the air bubbles out. I install it on the car first, so I can use the pedal to stroke it. I hate the little plastic "push into port" recirculators which come w/ most MC's. Those are just waiting to pop off the port. I cut some old metal tubes and added clear tubing to view bubbles.