i have the hydro boost on my wifes astro van, it was acting kind of funny about a year ago the brakes would apply really hard sometimes especially in the morning when cold i made a few calls around and none knew much. one guy said try to get some fluid out the of the oil resivoiur and put in some power steering fluid conditioner as there may be a sticky valve somewhere. is seems to have works almsot rith away as it went away and hasnt been bad since . remember power steering fluind resivoir not brake fluid resivoir.