I drive a 2004 Gs430, before I start replacing the abs master unit should I bleed or flush any brake fluid or is there any pressure that I may need to release before removing the unit? I have seen post and videos, some not relating to this car which are the ones who bleed or flush the system and only a couple relating to this car say nothing about bleeding or flushing before proceeding to remove the unit.

 

Heres Lexus's instruction. Makes no reference to draining, however step 6 was interesting to learn.