For the life of me I can't seem to get these brakes bled...

Everything is new. Thought I was good to go with everything installed, would pump the brakes during bleed process and get firm pedal. But as soon as engine running (booster) brakes just go to floor. I've tried gravity bleeding, and also rented a vacuum brake tool which was supposed to suck fluid from the wheels -- that was a joke and didn't work at all.

Decided to go ahead and pull the hard lines from the (dual) MC and try to "bench bleed" again, so installed two short soft lines from the ports to each reservoir. The problem is, no matter how much I depress the pedal, the air in the MC just flows through the tube but never completely out, so when you release it gets sucked back in. Over and over again, bubbles in the reservoir, but bubbles in the line which don't get all the way "out", so sucked back in.

Could really use some advice. This is the second MC from Speedway, as the first one seemed to have a leak at one of the unused ports. Wondering if this one is jacked, too??

Thx

 

Video for reference:

 

These help when you're going at it alone.

 

This may sound like a dumb question, but when you were bleeding the brakes, did you have some one to depress the peddle while you actually opened and closed the bleeder valve.

 

yep, three different people over different days…

 

how so? thanks for link.

 

if you get a firm pedal , and lose it when engine is running. does it come firm again when you shut engine off. sometimes i completely block of lines at mastercylinder,to be sure problems is not in the wheels or hoses. if you plug the 2 ports at mastercylinder does it do the same !

 

Here is a trouble that I shot when I did my brakes. I could not get good peddle after bleeding. It turned out that on my truck the main vacuum line from the manifold fed a junction block with several vacuum lines off of it. One line went to a Vacuum tank, another line went to a vacuum actuated control **** that opp-orated a piece in the pump, another line went to the brake booster, Big one mounted in the frame rails. These were original 3/4 inch hard rubber lines that looked like heater hose, but much stiffer to handle the vacuum. Thru all of this there were leaks. Blocked off the stuff I no longer needed, and put new lines in. Ant that was it

 

When bleeding your brakes are you starting at the back and working your way forward .
You need to start at r/h rear , then l/h rear , r/h front then l/h front .
Bleed each wheel until you have no bubbles appearing , and don't let the fluid get too low in the m/cyl or you will introduce more air into the system .
Do you get good flow at all wheels when bleeding ?

 

Disc or drum brakes? If discs,did you put the brake cylinders the right way? If not they will never bleed.

 

These bleeders have a check valve in them, you just crack one open at a time and pump the pedal. The check valve keeps air from being sucked back in when you release the pedal.

 

vacuum lines are new. also, would think that booster (vacuum) problem would mean that pedal would be harder not softer no?

 

yes, in that order.
front passenger doesn't seem to flow as well actually compared to the rest… but once pedal is firm and i start motor pedal goes to floor.

 

disc up front, drum in rear.
disc was conversion kit, all new, pre-assembled.

 

Make sure rear shoes are adjusted up or you will have a lot of pedal travel on the first pump.