replaced master, still spoungy

[kevs250]

i just replaced my master cylinder on my 70 f250
i just bled them and they better but still a little spoungy
when i first pump the pedal it goes to the floor, but when i pump it again it is perfect. soo do i still need to bleed some of the breaks?

[390Nut]

Did you properly bench-bleed the master cylinder before you put it in? If not, you're going to be going through a lot of brake fluid until the system is fully bled of air.

Also, pull your wheels and drums off and check all your wheel cylinders for leakage. Also check your brake lines for pinholes or rot. Old brake lines flex and expand more than new ones when you step on the pedal, which adds to the soft pedal feel as well.