Master Cylinder / brake Question

[AustinScott]

I Notice the other day that the brakes on my 68 where not working very well … (truck slowly stopping, pedal to the floor)
So I poked my nose under the hood & noticed when I removed the MC cover/lid that the fluid had drained from the front reservoir to the back reservoir, over filling the back reservoir & spilling out when I removed the cover..
I removed the wheels and drums in front to check for leaks and found none.
Does this passage of fluid from the front to the back mean I have a bad MC ??

Truck Specs:
68 ½ Ton Drum / Drum
Vac boost
All new rear brakes (rebuild kit, drums & flex lines)
New front brakes (rebuild kit, Drums resurfaced, flex lines & wheel cylinders)

NOTE: after the rebuild, I bleed the system 10 different times over a 2 week span, due to the brakes never feeling as firm as they where before I rebuilt them.
They did firm up a bit for a few 100 miles but now the pedal hits the floor after prolonged pedal pressure.
The truck stops but it makes you nervous to drive behind people because ti doesn't stop very quickly any more.

Now I noticed the fluid transferring thing & wonder if I have a bad MC….

Hmm... maybe its time to swap over to Disc…

If it is time which conversion kit is the best bang for the buck ECE or CPP?


Thanks

Scott