Vacuum brake bleeder

[ptolemyx]

Thinking about getting a vacuum brake bleeder. Any recommendations? Are the cheap fleabay ones at £15ish any good - look the same a sthe M&P and Sportsbikeshop ones at £50ish?? Or should I opt for something like this Sealey product, reduced to £25:-
https://www.demon-tweeks.com/sealey-bra ... 20Workshop

[billinom8s]

Do you have an air compressor? Says it needs 120psi.

[Grumpy Jase]

I had one of the Sealey bleeders (can't find it since moving house). I had pretty mixed results, as it seemed to introduce air into the fluid as it was being sucked out, so the fluid you could see in the tube was full of bubbles. This was even when doing a fluid change, where the brakes had been fine all along, and I was certin there was no (or very little) air in the system. I've not done a change for a while, so haven't investigated this further. They do need a compressor, and mine runs without a regulator, so it may be that I didn't get the pressure right, but I'm not convinced that was the issue. If you can do it the old fasioned way, I still think that's more reliable.

[Jug]

it seemed to introduce air into the fluid as it was being sucked out, so the fluid you could see in the tube was full of bubbles.

Yup... in the past I have tried similar with a large syringe and it did the same.
The bleeder nipples are designed to bleed under pressure and not from outside by vacuum. The action of opening the bleeder nipple (undoing it) also opens up the threads which can then allow air to leak in. This air doesn't get in the system but could still be in the bleed nipple when you close it.

The best bleeders are the ones that pressure in from the master, or from the caliper bleeder to do a reverse fill, but either-way they are pressure fills and not vacuum fills.

[Robbo87]

Ferzakly wot sayeth the Jug.
I too have wasted my dosh on 'miracle' vacuum brake bleeders in the past. Short of shelling out for a dedicated (and expensive) pressure refill system the best way is the old way - see multiple Youtube demos for how.

[Jug]

What I did do to make the process easier was to buy an inline one way valve (from ebay) and put that in some hose, and it works well.

[Robbo87]

What I did do to make the process easier was to buy an inline one way valve (from ebay) and put that in some hose, and it works well.

I didn't have too much success when I tried that, seems the 'air getting past the bleed nipple threads' might have been at work.

[Jug]

The final trick is to only just crack the bleed nipple. It needs to be still quite hard to pull the lever in.
Doing that seems to stop the air leaking by the threads, or at least minimizes it to such an extent that it no longer creates bubbles in the drain hose.

[ptolemyx]

Thanks guys. Looks like I'll keep on with the old fashoined way....

"Jane, squeeze it now"
"Jane, let go"
"Jane, squeeze"
"Jane, release"
"Jane, how does it feel now?"
Jane, is it hard yet?"

[layne]

Been riding and racing for over 40 years and we still do it by hand.

Some teams tell me it’s better forcing it from the bottom up.

Call me old fashioned but then I’m still heterosexual.

[royb]

Have had mixed results using the pumped vacuum system as previous bleeders.

Have found that using the master cylinder is best.

Crack the bleed valve, with a small visual tube from the bleed valve into a jam jar

With master cylinder open to top up when necessary, pump quick in, but slowly back to get full satisfaction.
Don't allow air to bypass the piston rubber when returning the levers to their standing positions. Go slow.

[billinom8s]

Patience, a good seat and fully open lever setting.

For stubborn ones, a syringe to pull the air out.

[Mervin]

syringe push fluid back up from caliper , if still a bit spongey cable tie lever to bar overnight air should work its way up