I've got an issue with the power brakes on my 58. When first applied,
they work fine. After a number of stops, the boost is gone and I'm
back to manual brakes. I understand that I still have full brake
operation, but I really have to stand on the pedal to stop.
I put a vacuum gauge on the tank. Under no-load idle It registers
about 6 in of vacuum. Bringing the engine up to about 1500 rpm, the vacuum
remains constant. Is this normal? Seems low to me.
When I measure the vacuum at the vacuum advance line going into the
distributor, it's zero at idle, and rapidly advances to about 15 inches at
about1200-1500 rpm, which I believe is normal.