I only did the clutch last weekend but need to do the others very soon, the clumps I found in the reservoir look the same as on the leaky slave cylinder. Terry the Mightyvac sure makes this easy, I connected the hose to the bleeder, set some pressure on it and just cracked the bleeder enough to see it draw slowly, that gave me time to keep the reservoir full, i did occasionally open the bleeder more to let any big bubbles come through but i was starting from a fully drained system. It is good advice to get this done.
