[Tom Goldman]

Make sure yu have a full 12 volts when the coil is energized. ...Make sure your ground is good. ,Don't ground the solenoid to the trans case ,use a good chassis ground.........On the Hipster brake you usually have to grind off a small ammount of the end of the modulator valve . ...If too much was removed the valve will leak when line pressure increases.......Check the solenoid first....Tom