SilberUrS6

...yesterday, I replaced the flex lines on the Green Machine. I rarely let rubber flex lines go more than 3 years before I replace them - at the current price, I could replace them every year and not notice.

I generally *never* go above 10psi with my pressure bleeder, because I'd rather not blow up the resevoir, then have the car down for days while a new one makes its way down the single dirt road to this burg.

I put 5psi on the gauge. I also use the canister as a pressure storage tank, and never, EVER use it to hold any fluids. I add fluid after every bleeder open/close cycle. The flow of fluid, under 5psig, was just fine.

Polyalkylethers (regular DOT3,4 brake fluids) are hydroscopic. But they aren't overly so, like solid sodium hydroxide or concentrated sulfuric acid. The amount of time the fluid spends in contact with atmospheric moisture is pretty small. Even at an elevated partial pressure (33% greater, at 5psig) water will go into solution only so fast, even with a very hydroscopic material. I spent a grand total of 15 minutes putting a liter of fluid through the system. How much longer would a two-man job have taken? 33% more? Longer?

I won't even talk about air, because the soluability of air in hydrocarbon liquids is really darn small to start with. And since the system is under vacuum rarely, and even then, very small vacuum, air bubbles coming out of solution seems incredibly unlikely, unless the system had been pressurized to over 3 atmospheres. (Think diving and "the bends", and that blood is really good at dissolving air.)

c4S6

I've been eyeing this "one man bleeder" kit for a while now. Price is reasonable and says you can even bleed the clutch with this method (which I believe is a problem with the vaccum bleeder).

Also, I have a nice big Craftsman air compressor in the garage that just doesn't get used enough!

I agree with Silber on replacing the flex lines. I plan to replace mine with new rubber flex hoses when I bleed them this fall.

I also highly reccomend Motul RBF600 brake fluid for any of you that do high performance driving. It's got the highest wet boiling point you can buy (except for Castrol SRF), but cost is very reasonable IMHO.<ul><li><a href="http://www.griotsgarage.com/search.jsp?searchtext=brake+bleeder">Griot's Venturi Bleeder</a></li></ul>

SilberUrS6

...and still pulls air around the threads of the bleeder screw, no matter how the vacuum is created.

If you want to buy a vacuum bleeder, I have one for sale. I'll sell it cheap. Nice, big plastic bottle to create a lot of vacuum, and hold a lot of fluid.

E-mail me if you're interested.