need help! no pressure when i brake!

[grandnash84]

hey all

got a problem i need help with. i just converted the rear brakes to disc and upgraded my front with 11inch 4 piston calipers. the problem i have now is i have very little pressure when i brake. once in a while on the 2nd pump ill get more pressure but for the most part its little pressure all the way around. i bleed the brakes for 4 hours so im pretty sure no air in the lines. can you guys give me any clues on how to get my brake pressue back? i have hydroboost btw. thanks guys

 

[seedling]

Did you install a new proportioning valve (for the 4 wheel disc set up)?


Sent from my iPhone using Tapatalk

 

[TexasT]

So, the pedal just goes to the floor, spongy pedal, how does it act? Plenty of fluid in the reservoir? Did you run the reservoir dry while bleeding,if so you have to start again.
Was it working well before adding the rear disks?

 

[grandnash84]

Did you install a new proportioning valve (for the 4 wheel disc set up)?


Sent from my iPhone using Tapatalk

no, one wasent included in the kit so i didnt think know i had to install a new one.

 

[grandnash84]

So, the pedal just goes to the floor, spongy pedal, how does it act? Plenty of fluid in the reservoir? Did you run the reservoir dry while bleeding,if so you have to start again.
Was it working well before adding the rear disks?

yes pedal goes to the floor. seems like when im crusing 15-20mph the pedal almost goes all the way down to stop. reservoir is full and i didn't run dry, and it was working perfectly before the conversion

 

[TexasT]

Master cylinder new , rebuilt, one from wrecking yard? If it goes to the floor I would suspect a bad mc. You say it works before. Maybe it doesn't have a large enough volume to do the disk caliper. Maybe a larger bore mc.

 

[grandnash84]

Master cylinder new , rebuilt, one from wrecking yard? If it goes to the floor I would suspect a bad mc. You say it works before. Maybe it doesn't have a large enough volume to do the disk caliper. Maybe a larger bore mc.

actually found the problem, my mc tooka dump and i got a new one and its all good!