I have old, ancient brake fluid in the clutch line that no doubt needs to be changed. Parameters: I am broke and alone (so almost no money and no helper for bleeding). Over the last few months, my clutch pedal has slowly sunk lower and lower and now the engagement point is in the very last inch or so from the floor. Everything above that is nothing with no resistance. Last winter, I had some problems with the clutch pedal sticking to the floor when it got very cold - and the cold weather is almost here. So my theory is that there is moisture in the ancient fluid and it froze at those times last winter. I also figure old crappy brake fluid would cause the pedal drop. I doubt there is air in there but that’s a possibility too. Anyway, I am having trouble finding the specifics of how to fully bleed the system by yourself. I know about the vacuum thing that costs $40 or whatever but my price range is more like the $3 for the new bottle of fluid and that is it.
I have been told that what I should do is just suck out the fluid in the reservoir and then fill it with new fluid and just keep repeating that once every few days for the next few weeks until the fluid is nearly all changed-out. Does that work? Does all the fluid just mix and circulate so that bleeding really isn’t needed using this method over time? If not, and the whole thing must be bled out and totally replaced with new fluid all at once - by myself - then what is the best method? I thought that the fluid in any given spot in the line or reservoir would not really move, just get pushed back and forth. So which is correct?