hey, i have a 1959 viking and i removed all 6 wheel cylinders and the master cylinder, honed them out and bought and installed rebuild kits for all of them. I then bled them untill i was positive all of the air was out. when i though i was done i pumped the pedal a few times and the pedal got hard about half way down but once i let off and pushed the pedal about 5 seconds later it went to the floor. i then pumped it another 3 times and held it when it got hard and it did not lose any pressure even after holding the pressure on it for about 5 minutes the pedal still remained hard. If anyone has any idea what might be going on i would sure be greatful to any help or suggestions! thanx!

'53 3100
'59 viking 60