Brake bleeding problems

[cfranklin013]

I have run out of things to check . I have replaced my complete brake system on my truck ,now I cant get the brake pedal to pump up . I have gravity fed the brakes, fluid runs good through all for corners. I have benched my master cylnder three times ran 3 qts of fluid out of the whole system . The brake pedal will get stiff but will never pump up then when it sits for a few seconds it will be loose again . I have no leaks that I have found .should be dripping on floor after 3 qts of fluid . The details are 9" booster corvete style master front and rear disk new prop valve all new lines . Any help will be appreciated . Im over looking something .

[wedgemon]

Is the M/C new? Bad seals can allow fluid to flow past.

Same problem on my 80 K10

[suicide 63]

Originally Posted by cfranklin013

. The details are 9" booster corvete style master front and rear disk new prop valve all new lines . Any help will be appreciated . Im over looking something .

Is it a disk/disk prop valve
and I have read you need 3/16 line for disk brakes instead of the 1/4 in used for drums.

[cfranklin013]

MC is new but now days that dont mean any thing . I havnt heard that I need bigger line for rear disk. The prop is not for disk /disk I dont believe . I have been looking into that if there is much diff between the two .

[suicide 63]

again i am no brake expert but thece are things i have read on different forums.the drum brakes need the bigger line so if you cnverted to disc brakes on the rear you would need to run 3/16 line to it instead of the 1/4 inch line that would normaly be on the truck. Yes you need to change the prop valve to Summit has some adjustable ones for a reasonable price.I am sure someone else will be along here shortly to help you out.