Reverse Brake Bleeder

[Por_sha911]

I get a catalog from a well known detailing supply company. They have something called a reverse brake bleeder:
"Instead of pulling air down through the system, this tool pushes the air up where it naturally wants to go."

Whenever I've bled my brakes I used a simple hand tool that sucks fluid down and out of the caliper:

Pushing fluid and air up seems to make sense. What am I missing? Didn't find anything while searching.

[dad911]

Looks like a bad idea to me. You want to get the fluid out of the caliper, especially if it's been heated/cooked on a track car.

So this will push the crusty old fluid and air up into the master cylinder, and possibly the abs system on newer cars....

I like to pressure bleed mine, like the Motive.

[RSTarga]

that is a silly idea, as stated above you have to bleed the old fluid out

[dad911]

How do you get the old & overflow fluid out of the reservoir?

It could also push dirt from the bleeder into the system.

[Por_sha911]

OK. I guess I didn't think it through.

[m110]

Kind of like trying to clear your clogged toilet by plungering at the sewage main out front.

[lewmanbubba]

The tool that you have pictured is called the V-12 DIY Phoenix Injector. It is a very useful tool if you are removing air bubbles from your brake or clutch system that is causing a mushy brake pedal or clutch engagement problems. This tool is a hydraulic hand pump that can perform both vacuum and positive pressure techniques that allow you to bleed all hydraulic systems. Some of the fears I read were pushing contaminated fluid back up through the system. The tool operates at 10 PSI which is normal brake system pressure. Contamination by pushing fluid back to the master was caused by using a pair of channel locks to push the piston back in the caliper creating 90 PSI thus dragging all manner of contaminates hard and soft back to the master and ABS. This could have been avoided if the soft hose had been disconnected or at the very least the bleed screw opened. I also notice that people confuse flushing with bleeding. Flushing is exchanging old fluid for new fluid this can be done by vacuum at the bleed screw or pushing fluid down from the master. Bleeding is removing air from your system. The best way we know how is by pushing fluid into the bleed screw and back up to the master. Go to brakebleeder.com and look around there is lots of info and videos

[combatic]

Just get a Mityvac system and be happy for the rest of your brake bleeding/fluid removal days. I have tried the Motiv <--horrible (positive pressure at the reservoir) product and other bleeders and Mityvac is by far the best and most useful system I have used. You can vacuum out any oil product! (trannies, pumkins, oil tanks etc)
.....and no, I don't wear pleated front kahki's when I change my brake fluid

[Joe Bob]

Would make more sense to me, to suck it out......

[dad911]

Originally Posted by lewmanbubba

The tool that you have pictured is called the V-12 DIY Phoenix Injector...... brakebleeder.com .....

lewmanbubba is obviously affiliated with brakebleeder site and that product.......

Originally Posted by lewmanbubba

Flushing is exchanging old fluid for new fluid this can be done by vacuum at the bleed screw or pushing fluid down from the master.

Like the motive or mityvac, etc.....

Originally Posted by lewmanbubba

.......The tool operates at 10 PSI which is normal brake system pressure.....

?????

combatic - what was your issue with the motive? While I don't use one, I basically do the same thing with a dryer, secondary pressure regulator, and modified cap connected to my compressor/shop air.

[Quicksilver]

The possible problem with vacuum bleeding techniques is that the brake system was never designed to deal with vacuum. The seals were all designed simply to deal with pressure.

It is possible for the vacuum to pull air past the seals creating a situation where it never bleeds out correctly.

Pressure bleeding uses the system they way every piece of it was intended to operate: Under pressure.
(With the exception of the reservoir as mentioned earlier.)

[Walt Fricke]

Sellers of positive pressure, caliper up, bleeders assert that this is aeronautic practice. If true, that's a pretty decent endorsement.

Fact is, there are at least half a dozen ways of bleeding, each with some plusses and some minuses.

The promise of this one, if I understand it, is that (after emptying the system of all old fluid) you can be assured that when fluid reaches the reservoir, you will not have any air in the system. You can stop, top off, and be done. I've not seen their instruction sheets, but think this would involve, for each caliper pair/reservoir, pushing fluid from caliper A into the reservoir, and then pushing fluid from B there to be sure the air in the B only segment of the lines was removed. If this happens as a slug of air into the reservoir, followed by no more, this might work as advertised.

I tend to jump around depending. My major gripe with vacuum systems is that I can never be sure when I have gotten all the air out, because some gets in around the bleeded, only to get promptly sucked out. Doesn't cause problems down the line, but I am not sure when the air I am after has been removed. After a while I just assume it has been, and that has proven a justified assumption.

[combatic]

Originally Posted by dad911

combatic - what was your issue with the motive?

dad911,
Here are my problems with the Motive Universal Power Bleeder + pushing fluid rather than sucking it at the brake.

1. If the seal between the Universal Motive and your reservoir fails during bleeding it blows brake fluid all over your trunk/engine compartment! The large seal is created by wrapping a chain around the reservoir using J-bolts and wing nuts. This puts stress on the reservoir connections, is hard to keep located to maintain the seal and with such a large surface area ultimately fails. In theory it is a one size fits all solution.
NOTE- Motive does make 'caps' that screw to your specific reservoir for a better seal but they are added cost and how many of us have multiple vehicles to include bikes which means you would need to use a different adapter for each.

2. If the Motive reservoir runs low it injects air into your system under pressure!

3. You risk contamination transfering fresh brake fluid to the Motiv container.This method could lead to contamination if you are not careful and start with a clean Motiv reservoir. (this isn't high risk but it adds steps and what do you do with the leftover in the Motive container???)

4. Motive is only for brake bleeding. The MityVac system allows you to suck any oil out of any car reservoir or container. ( I use it all the time, power steering fluid, emptying drain pans, diffs, etc)

5. You can not suck up all the nasty stuff in your reservoir before bleeding with a Motive. Mityvac can...so you don't push particulate all the way through your lines.

Once I used the Mityvac, all the fusiness, mess and headache went away and made me stop and say, 'What a great product!!!!'. The above is just my personal experience. I am sure you can push brake fluid with no problems....there is always more than one way to skin a cat! I would like to hear someone else's pro & con's.

[wildcat077]

I've used a Mity Vac system in the past,matter of fact the case is gathering dust in my garage ever since i purchased a Motive Power bleeder from our host ...

I will never go back to any other system as i've done my Porsche a few times along with
my F150 and my son's Civic by using the universal adapter !
Bleeding brakes ... down to a simple one man operation

Cheers !
Phil

[wildcat077]

Bryan,

For what it's worth,i've completely flushed the brake fluid in my 911 three times so far as well as a complete flush in my pickup and Honda and i never added any fluid to the Motive bottle.

If you monitor the fluid level in your master as well as the pressure in your Motive it's a piece of cake and if you use the Porsche aluminium cap there are no chances for a mess ...

Just sayin ...

Cheers !
Phil

[m110]

Firstly, don't use the Universal model shown, just get the one for Porsches (and other German cars)
From my college inorganic chemistry class: if you rinse a clean motive bleeder with fresh fluid twice the residual old fluid is essentially nil.
If one wants to just bleed, the Motive can be used empty as a pressure source with no mess at all.
It will inject air if you go through the entire volume and don't pay attention. Pay attention.
Nothing wrong with the Mityvac...numerous factory shop manuals now show changing the oil on the ground, no hoist, no drain plug. Not my preference.

[combatic]

Originally Posted by wildcat077

Bryan,

For what it's worth,i've completely flushed the brake fluid in my 911 three times so far as well as a complete flush in my pickup and Honda and i never added any fluid to the Motive bottle.

If you monitor the fluid level in your master as well as the pressure in your Motive it's a piece of cake and if you use the Porsche aluminium cap there are no chances for a mess ...

Just sayin ...

Cheers !
Phil

Originally Posted by m110

Firstly, don't use the Universal model shown, just get the one for Porsches (and other German cars)
From my college inorganic chemistry class: if you rinse a clean motive bleeder with fresh fluid twice the residual old fluid is essentially nil.
If one wants to just bleed, the Motive can be used empty as a pressure source with no mess at all.
It will inject air if you go through the entire volume and don't pay attention. Pay attention.
Nothing wrong with the Mityvac...numerous factory shop manuals now show changing the oil on the ground, no hoist, no drain plug. Not my preference.

Cool! The Porsche/German cap seems to be the trick. Do not use the universal system. My experience was way back when I had my Miata and probably due to operator error. Now who did I loan my MityVac to? ha ha. Thanks for the tips!

[Bob Kontak]

Regardless of what system I use (foot and a friend, little Mity-Vac or Motive), my best results come from bleeding twice, (or flushing then bleeding) with a couple of days driving in between.

Maybe the two directional Phoenix unit can loosen up bubbles that evade the traditional methods?

[wildcat077]

Bryan,

I had the same concerns as you before i purchased the Motive bleeder with the billet cap for Porsche master cylinders.
I replaced the four calipers with 996TT units,installed a brand new 23mm master cylinder and all new stainless flex lines and i had to fabricate the four hard lines when i did my brake upgrade.
Basically a start from scratch with lots of potential for air ... lol

I used the Motive pressure bleeder by myself and the results were spot on ... no brake pedal/fade/firmness issues at all.A complete brake fluid flush before every track season is a charm ...

You will truly enjoy it !

Cheers !
Phil

[john walker's workshop]

i don't fill the Motiv with fluid. too messy. drill a hole in the top area and install a metal tire valve. suck out all the old fluid from the reservoir with a big plastic syringe available at drug stores, wipe out the remaining grunge, fill the reservoir with fresh fluid, attach the Motiv with the porsche style cap, pressurize to 25# and keep an eye on reservoir level as you bleed. don't forget to pinch off the overflow hose on the reservoir.