Originally Posted By: flyingtoaster
I can't think of any logical reason why not, other than the reservoir draining 4x faster, and the fact that there is a bleed order for my car (which many people go by a different, unofficial order).
You sure can bleed all 4 at the same time. Just use the "gravity" method. That's where you simply open all the bleeders at once and allow the fluid to run through by itself, keeping a sharp eye on the reservoir so it doesn't run dry.
The problem I've found with the gravity method is that the calipers/cylinders don't always want to "start" unless you use a Mity-Vac, or mouth suction through a hose to get them going, and the dripping fluid can make a real mess on the brakes and floor. Putting hoses on caliper bleed nipples tends to prevent gravity from working, since caliper nipples tend to point upwards.