Hi and Welcome to Just Answer! My name is Pavlin and I will do my best to help.
when you say everything, does this includes rear brake shoes
yes, and cylinders and drums. new calipers & lines in front.
I am asking because if rear shoes are out of adjustment is can do that.
and a new master cylinder
is it you doing the job or garrage?
when bleeding the system, do you have engine running?
bleeding must start with the wheel which has the longest line. Rear passenger side
then rear left
front passenger and drivers front last
thats what we did, using speed bleeders
if you have good pressure, and read shoes are adjustet well, then problem is most likely in rear ABS valve
look in inner frame under drivers seat
we bled abs valve also. is there a way to test it?
you can reroute the lines and by-pass it . but they have are known to cause problems like this due to internal leaks,
if you will have brakes after by-passing it, then you know what is going on.
we did that and nothing changed
Then you are havong bad muster cylinder
have tried 3 new master cylinders
did you match the part number from the old one to the one you have purchased? remove muster and check pushrod from brake booster lengt.
measure protrusion of pushrod and then master cylinder hole dept.
when master is bolted to brake booster it should be bearly touching the pushrod.
made up a guage according to manual, 0.995 inch, and adjusted pushrod according to gauge
check the dept of the master and compare with you gage
did that, it is just touching
if you crimp brake line to rear brakes what happens?
crimp brake hose
to isolate rears
did not try. can i safely crimp with pliers the rear hose from frame to the T on axle?
yes, just use somthing to protect the hose from damaging
can we try this and come back to you?
how do i do that? hit save & exit?
you are welcome