Brake problem

Hi guys,

Just a quick question, finally got round to bleeding my brakes last night. The rear one bled fine, but when i come to bleed the front, nothing.

I have to a dual master cylinder with a 5 way splitter, 2 inputs from the master cylinder, 2 outputs to the front and 1 to the rear.

I dismantled the pipes to the front to see if any were blocked.

When i disconnected the pipe to the master cylinder, there was no fluid leaking out, even when i pumped the brake pedal.

What could be wrong?? I wouldn't have thought the master cylinder is faulty as its pumping to the rear brakes...

Any ideas welcome..

5 way splitter is pdwa valve (pressure differential warning actuator)it has a shuttle inside which if pressure is lost front or back it it forced over to low pressure side by pressure in good side .puts light on in cab as warning,and stops fluid traveling down failed line making bleeding difficult ,to reset you need to open other end to one you where bleeding front or back,when bleeding trucks with these valves slow controlled pumps on pedal are required fast pumps create pressure differential ,master cylinder is two pumps front and back lines ,sometimes you need to bleed at clyinder eithe by slackening union while before pressing pedal and tightening before letting pedal up repeat till fluid flows well ,sometimes removing pipe is necessary and using finger to close hole before letting pedal up ,splashing of fluid in reservoir indicates poor master cylinder seals rear most pipe on master should operate front brakes ,front most pipe rear

But i have disconnected the brake pipe where it connects to the master cylinder (the rear one) and there fluid is no fluid coming out of the master cylinder.

Could this just be blocked or is it broken??

have you tried using finger as valve ,if full of air its easier for air to be pushed back and forth then to suck fluid from reservor

Yeah tried that still nothing, so theres no reason for the master cylinder to work for the rear brakes and not the front..

could easy have inverted seal or worn seal may need new master cylinder

Ok ill have to take it off the weekend hand have a look at it.

Cheers