Bleeding Clutch Hydraulics Backwards?

In theory, it should work.......but Step 1 is pushing a bunch of air through the slave, and hoping it all gets out as it's filled from the bleeder. I guess the density of pushing the fluid upward should keep things pretty solid.

I used a Speedbleeder on the Boxer's clutch slave, made life easy, with just little ol' me.

Whichever you choose, lots of tapping along the route, especially the cylinders.

 

Never tried priming a system this way. Certainly a typical brake system allows fluid to push back up past the master to the reservoir. We all do it as we push back the caliper pistons to fit new pads for old.

Is there any benefit to the technique though?

 

I use a vacuum bleeder like this one.

http://www.griotsgarage.com/product/multi+fluid+extractor.do?sortby=ourPicks

Frequently gravity is good enough with a clutch because the lines are short. Just open the bleed screw and see if anything comes out.

 

Also would avoid the messy and bad things that happen with a pressure bleeder (which is the same one person idea, except done from the reservoir end, as is traditional) when there is a leak anywhere in the normally unpressurized area above the master cylinder.

One possible downside is that the reservoir could fill before all the air is out. You'd have to stop, siphon the excess out of the reservoir, and then continue.

 

Appreciate that but I meant is there any benefit with reverse filling over pressure filling from the reservoir?

 

I've always thought there was merit in trying to push air upwards in its natural direction (from the slave or the calipers back to the master), instead of downward (the conventional way), but the reverse bleeding doesn't seem too popular. Probably because of the potential for dislodging & pushing accumulated grunge up into the master? (like the effects of reverse flushing a cooling system?)

I've also wondered about fitting a small vacuum pump on the master reservoir and pulling a small vacuum on the system to "pull" entrained air out of it. Would have to be a bit careful not to pull too hard and pop the seals in the system which are rated for high pressure, but probably not rated for vacuum.......

 

Recently I was bleeding the clutch of the Testarossa. I've always used the mity-vac method in the past, but my professional mechanic buddy had a snap-on "push" type bleeder and told me to try it. It did work okay, just don't get too enthusiastic...go slow and easy. Yes there is the possibility of overflowing the reservoir if your not careful. As Mr. EHAMILTON pointed out....you could fill up the reservoir before all the air is out - I never thought of that. All in all....I think I still prefer the vacuum method, or a helper to push the pedal while you operate the bleeder fitting.