You have to watch how you fill the reservoir and keep it full. There is a rear chamber that can run empty when the forward chamber looks to have fluid. If you don't keep both chambers full, you won't do a proper job of bleeding the system.

The Motive power bleeder or any pressurized bleeder for that matter takes care of this problem since the reservoir will be full. Actually, beyond full.

I think what Larry was referring to is a reservoir with cracked vent caps or sensor seals. These items are above the operating fluid level so fluid doesn't have a chance to leak. When you pressurize the reservoir with fluid, you'll know quickly if the seals need replacement.

Sixto
95 S420
87 300SDL