Brakes

my son has 1987 dodge pickup. 318ci 4x4. It is drinking 2qts of brake fluid a week. There is no visible signs on leaks on any wheel or line. No leaks in cab under dash. Is the master cyl. leaking into the vac boost? Maybe gettin sucked back into the intake? Any help apprieciated.

2 quarts a week?!?! It has to be going somewhere. If there are no visable leaks then I would suspect the booster.

Remove the vacuum line from the booster and check for brake fluid.

If there is fluid in the booster, it would be a bad seal in the master cyl. right?
Or would there be something wrong with the booster?

If the booster has brake fluid in it, the rear seal of the master cylinder is leaking. The master cylinder and booster have to be replaced.