95 one ton brake problem

[qwertydog]

I had a rear line blow so I replaced it and bled the system. But the pedal still went to the floor ! Thinking it must be a worn master cylinder I have just replaced it with a new one and bled the whole system again using my vacuum bleeder. Still no luck, if I pump the pedal a few times I get a LOT of air out of the front right caliper. I have done this about 10 times today with the same result. I have worked on many brake systems over the years but this has got me stumped. With all the bleeders tight there is absolutely no leak anywhere, so I cannot figure out where the air is getting in. I hope someone can guide me in the right direction. Thanks.

[maxwedge]

If this is an abs equipped truck and the system ran dry, the abs unit must be bled, most times this requires the use of a bi-directional scanner that can actuate the internal solenoids in the abs unit to purge the trapped air.

[qwertydog]

Thank you for the speedy reply. Yes, this truck is ABS equipped and the system did run dry. However, as it is never used on public roads and I do not have access to a bi-directional scanner, I will have a look at it tomorrow and see if it is possible to remove the brake lines from the ABS module and connect them directly to the master cylinder. Might take a bit of new line and some fittings but should be workable. Thanks again for pointing me in the right direction, I will post the results of my efforts