spongey brake pedal need help

[midget]

My brake pedal is spongey now(it wasnt perfect before the SAS) but the truck stops seemingly fine. Would this be because Im using dual piston front calipers with a stockmaster cylinder? If I unhook the Vac booster its all good but when I plug it back it it returns to spongey. Its not air in the lines Ive bled the brakes 3 times now and no air just lots of wasted fluid...

 

[Tader82]

did u reuse the old RUBBER lines, they can become worn out and make the brakes feel spongy, best bet is to get a set of breaded steel lines fixed my spongy brakes

 

[midget]

The rear has been switched to all nylon brake line (lightweight racer kit) which I have used before with great succes and ease of instillation and the drivers side brake line is steel braided while the passenger side is still a rubber line.... (dont ask why) but its a brand new rubber line the parts store couldnt get me a steel braided line in time.

 

[Sasquatch_Ryda]

This is a d44 you swapped in the front?

My buddy had the same issue with his 87 B2 after swapping in a d44 and 9", the pedal was spongy with the bigger brakes and stock master cylinder.

He swapped in a master cylinder from a 79 f150, problem solved.

 

[midget]

Ok thanks a bunch Ill get it changed and hopefully that will fix it.