1999 Volvo V70 "compressor drain valve broke" Questions

...drain the oil. Remove fuel lines to and from the engine, remove the electrical and vacuum lines that lead to and from the intake manifold,remove the alternator, air pump, ac compressor, tie it back, ...

...drain battery completely . However there is also belts you can check to make sure there tight, and not broke of course or slipping. There is your first step, for free check, and most likely , with ...