It is not a matter of something wrong with Speedbleeders perse (though I'd recommend getting the stainless steel units over the standard carbon steel ones). The issue is pumping your master cylinder to bleed the system. Whereas Greg may disagree, I know from experieince pumping the MC strokes the piston into the bottom of the cylinder bore where all sorts of nasty crud lives not normally visited. This crud and possibly oxidation can tear the o-rings on the piston with bad results. Furthermore, tightening and loosening the bleed nipple several times using the pump & wrench method (though less so with a Speedbleeder) ruins the thread sealant or teflon tape quickly and makes it more difficult to keep air out. Using a MityVac or pressure type bleeding equipment obviates touching the lever and pumping the piston into the bottom of the MC bore but the spring pressure of a Speedbleeder check (ball) valve cannot be overcome my a vacuum bleeder. with a MityVac, it takes me 15 minutes to set up and bleed the front brakes and 5 minutes more to do the clutch, which is a bit trickier; the rear is another 7 because its awkward getting to the nipple. Its also a lot easier to bleed any empty system by vacuum or with pressure.

Tip 1: When simply bleeding to flush a system, suck out the old fluid in the resevoir before adding fresh with the MityVac or small turkey baster (do not get the fluid in the rubber bulb). Tip 2: For bleed nipple thread sealing, the yellow teflon tape for gas lines is better than the white but regardless chase the tape into the threads after winding counterclockwise 2 laps max. Do not use hardening type thread sealants. Speedbleeders come with a non-hardening thread sealant that is good for 2 or, at most, 3 careful bleeds and then must be replaced. They sell it in a bottle but their last supplier screwed up with a bad batch and they are looking for a new vendor. It is expensive compared to teflon tape. Tip 3: Do not over-tighten the bleeder nipple whatever you do; the pump & wrench method makes this difficult not to do because rapid closing of the bleeder nipple minimizes air bubbles.

 

+1 on the teflon tape and mityvac. GREATLY reduces time and effort. I've had one set of speedbleeders and they do what they promise.

 

Are you saying you were able to use a Mityvac on a Speedbleeder?