caravan breaks

[guest]

howdy, break problem 2006 cargo caravan . replaced master cylnder bled all breaks no air in lines.
van not running, 3pumps of pedal, comes to the top, firm, no by pass. start van with foot on break, it goes to the floor never to get very solid. test drive car will stop but has spongey pedal,about half as hard as normal. bad vac booster? no abs lights on

[carriedi]

you might have to use a scanner and check to see if there is a brake bleed procedure for the ab s accumulator.

bleed the brakes manually. hook up the scanner and go to the abs section. Under the miscellaneous section there should be a place to bleed the brakes for the HCU. After using the scanner to bleed the HCU do a manual bleed again. that should get you going again. (all other conditions being normal. why did you replace the master to begin with?)

[carriedi]

you might trying to disconnect the vacuum line to the vacuum booster and plugging off the hose and then start the engine and see what the brake pedal feels like. Does it still feel like a high and hard pedal or does it still go to the floor...

If the pedal is near the top and hard to push with the vacuum not connected then it could be a booster problem. Because the HBC is acting normally. If the pedal still goes to the floor then it is probably the HCU causing the pedal problem because the booster is acting normally with no vacuum