Motive brake bleeder question.

[PoorOwner]

Do you guys just pour the fluid in the car and use the tool to pump air, but not in the bleeder reservoir like you are supposed to?

Which method is better and why? Seems like the first way you will be opening and closing the cap a lot. But you don't have to clean the bleeder.

 

[trackwelder]

I have several units set up with different adapters. I just add some fluid from a new container and bleed away. Not much to clean the unit afterwards.

 

[mhm993]

I Fill the car reservoir and use the motive pump "dry". I've been doing it this way for years.

 

[rice rocket]

I always used mine "dry", just as a pressure accumulator. It's more hassle, since you have to unhook to refill, but it's the cleaner option.


P.S. I have one w/ a universal lid for sale if anyone is interested. Shoot me a PM.

 

[MikeF2316]

Put me in the air only category. I think that if your were doing brake fluid replacements or bleeding several times a day, every day it would pay to use it wet. But I'll bet I don't even use mine once a year on average. But it sure makes it quick & easy!

 

[Schurkey]

"Garden Sprayer" brake bleeders are not recommended. If you're using them dry, you could just gravity bleed and save the cost of the garden sprayer. If you're using them as a fluid reservoir, you're contaminating the fluid with the humidity in the air.

 

[M6erfan]

I've got one, use it fairly often...dry

 

[MikeF2316]

"Garden Sprayer" brake bleeders are not recommended. If you're using them dry, you could just gravity bleed and save the cost of the garden sprayer. If you're using them as a fluid reservoir, you're contaminating the fluid with the humidity in the air.

Some systems will not gravity bleed if they have too much air in them. Clutch hydraulics are notorious for this. In fact trouble bleeding a clutch was why I bought mine.

 

[67King]

I fill the Motive. I'm not sure why you say you aren't supposed to do that, it has a tube to pull off of the bottom. THat said, I'm more often flushing an entire system than not, I can't imagine how many times one would have to refill to move over a quart/liter of fluid without the risk of pumping air (and I've done that even with the Motiv filled). I also always use the same brake fluid (Millers Racing Brake Fluid) and only in my car, so maybe that is different. FWIW, that's the only way I've ever seen anyone do it at the track, be they shops or individuals.

Of course, if I'm cleaning out the lines (emptying, blowing through, then refilling), or if I have a lot of air in the lines, I'll use the pedal to move the fluid, but I keep the Motive on it to ensure I don't run out of fluid.

 

[winlinmac]

Where do you all recommend purchasing the Motive Brake Bleeder from? Is there a particular price range I should be looking? I need to bleed my brakes soon, and cheapest I found was $50 for the Brake Bleeder.

 

[kcheves]

I also use mine dry because I'm paranoid about the hose bursting and taking the paint off the car. I refill the brake fluid reservoir after bleeding each corner.

If you have a German car, spring for the nicer version with the metal cap for the brake reservoir. Cars without screw on caps (Honda, maybe others) require a fiddly universal cap.

 

[rjacobs]

I use mine dry as well and de-pressurize and fill the master cylinder in between each corner.

Might take longer, but I am not wasting fluid.

 

[theoldwizard1]

"Garden Sprayer" brake bleeders are not recommended. If you're using them dry, you could just gravity bleed and save the cost of the garden sprayer. If you're using them as a fluid reservoir, you're contaminating the fluid with the humidity in the air.

Why ? It is the same air that is in every other brake bleeder ?

 

[928'er]

"Garden Sprayer" brake bleeders are not recommended.... If you're using them as a fluid reservoir, you're contaminating the fluid with the humidity in the air.

Sure, brake fluid is hygroscopic, but you are aware that your brake system vents to atmosphere aren't you? That's one of the reasons it's necessary to periodically flush the system.

 

[6PTsocket]

I have always used mine wet. Even though I have the O rings lubed I have always found that I have a harder time getting pressure with no fluid in it, . Add fluid and it pumps right up. I don't like the idea of not seeing the fluid level and having to lose pressure to refill. If you are just going to use it dry, why not just buy the adapter cap and run it off your compressor with a low pressure regulator set to 15 PSI?

 

[Schurkey]

Some systems will not gravity bleed if they have too much air in them. Clutch hydraulics are notorious for this. In fact trouble bleeding a clutch was why I bought mine.

For small work, I gravity bleed. For major work, I drag out a REAL pressure bleeder--in my case, a Branick or a KD (now Gearwrench).

Why ? It is the same air that is in every other brake bleeder ?

A REAL pressure bleeder uses a rubber diaphragm to separate the compressed air from the fluid. The compressed air never touches the brake fluid, and therefore the brake fluid doesn't absorb water from the compressed air. The crappy "garden sprayer" bleeders don't separate the fluid from the air.

Sure, brake fluid is hydroscopic, but you are aware that your brake system vents to atmosphere aren't you? That's one of the reasons it's necessary to periodically flush the system.

Name a brake system that vents to atmosphere. I've never seen one. Please be specific--make, model, year.

That's the point of the accordion-pleated rubber seal under the master cylinder cap. Just like a REAL brake pressure bleeder, there's a rubber diaphragm between the fluid and the atmosphere, dramatically slowing-down the moisture absorption. At the other end of the system, rubber seals on or behind the pistons seal the fluid in, but also seal air (and therefore humidity) out.

why not just buy the adapter cap and run it off your compressor with a low pressure regulator set to 15 PSI?

Again, I think this is going to be a wet system, (and of course with extremely-limited fluid volume) but it beats buying a garden sprayer at 4x the cost. 15 psi is MORE than enough.

 

[rice rocket]

Name a brake system that vents to atmosphere. I've never seen one. Please be specific--make, model, year.

You're not thinking. All brake systems VTA.

What do you think replaces the fluid in the reservoir after your pads wear down? Do you think you'd be able to get your reservoir cap off if no air replaced that lost volume?

 

[Schurkey]

You're not thinking. All brake systems VTA.

What do you think replaces the fluid in the reservoir after your pads wear down? Do you think you'd be able to get your reservoir cap off if no air replaced that lost volume?

Think harder.

The atmosphere is on the OTHER side of the accordion-pleat rubber seal. The atmosphere doesn't touch the brake fluid until you remove the reservoir cap.

Until then, the fluid displacement from brake actuation merely moves the accordion-pleat rubber seal back 'n' forth, and as the pads wear and fluid is displaced, the accordion-pleat seals gets "vacuumed" into the reservoir body.

It is still a sealed system, with fluid separated from air--but not from air pressure. Very little moisture gets past the rubber seals. Just like in a proper brake pressure bleeder where the atmosphere and the brake fluid are separated by a rubber diaphragm. Seriously...you guys have never had to re-fold the pleats in the seal after adding fluid to a master cylinder reservoir?

Brake engineers know that allowing atmospheric air to touch the brake fluid any longer than absolutely needed during brake system service is death to brake fluid, and promotes system corrosion. OF COURSE the system is isolated from the atmosphere with rubber diaphragms and seals.

 

[Spire]

I do both depending on which cap or adapter I'm using. If it screws onto the master cylinder then I will fill the bleeder.

If I'm using the aluminum cover plate (older oval master cylinders) then I do not fill.

I found that using 4 of the Irwin Quick Clamps makes removing and installing the plate much faster and easier than the silly chain included with the adapter.

 

[rice rocket]

Seriously...you guys have never had to re-fold the pleats in the seal after adding fluid to a master cylinder reservoir?

I honestly have never seen that in my life.

Modern cars have something like this. Maybe it's been determined that the tiny amount of air that enters really doesn't make a difference in the grand scheme of things?

 

[Schurkey]

I honestly have never seen that in my life.

Modern cars have something like this. Maybe it's been determined that the tiny amount of air that enters really doesn't make a difference in the grand scheme of things?

Wow. That sort of cost-cutting astounds me. Even my CB1100F and my (now deceased) '80 Civic have rubber diaphragms on the master cylinders.

My first thought was that Honda wasn't using hygroscopic brake fluid any more...but a quick internet search turned up plenty of hits for "genuine" Honda DOT 3 fluid, and none for silicone- or mineral-oil-based brake fluids.

 

[rice rocket]

Brake fluids do indeed continue to be hygroscopic, but without measurement, you're just guessing as to how much of an impact that tiny bit of air transfer actually makes. Is it 1 degree of boiling point per day? Per year? Per decade?

My guess is they've measured it and deemed it unnecessary, as I don't see modern cars shooting off the highway with it's drivers pumping frantically.

 

[rice rocket]

Also consider that the reservoir sits in an engine bay, which when you heat it to operating temp, will push out the liquid/gas with the lower vapor pressure.

 

[lbhsbz]

Some systems will not gravity bleed if they have too much air in them. Clutch hydraulics are notorious for this. In fact trouble bleeding a clutch was why I bought mine.

Think about what you just wrote for a minute...and the think about the weight of air vs any liquid, and finally the vertical separation of the master and slave/bleeder valve.

 

[lbhsbz]

Sure, brake fluid is hydroscopic, but you are aware that your brake system vents to atmosphere aren't you? That's one of the reasons it's necessary to periodically flush the system.

It's Hygroscopic

 

[lbhsbz]

I'm the head tech for Centric Parts/Stoptech.

It's not hard to find a friend/wife/kid walking down the street that could use $5 to sit in the car and run the pedal. Forget contamination the fluid with moisture...you're putting pressurized air on top of the fluid with a Motive. Not a big deal for street cars, but on a performance or race application, it can be detrimental. A branick diaphragm style bleeder is best, or get someone in the car. Forget vacuum bleeders, they just pull air around the bleed screw threads. The objective is to always maintain higher pressure on the wet side of the system than the dry side.

 

[928'er]

It's Hygroscopic

Ooops, thanks for the correction.

 

[mhejl]

Used the Motive wet once. What a mess. Then dry once. Then, just the adapters connected to the compressor dialed down to 10-15 PSI. Why pump the motive when you have a compressor? The Motive was a waste of money, IMHO - I should have just bought (or made) the adapters and added a Milton QD to the hose.

 

[nh_yota]

I have a Motive power bleeder that I used one about ten years ago when I bought it. I filled it with fresh brake fluid when I used it and it worked okay, but I never quite trusted the fiddly adapter to not slip and spew brake fluid everywhere.

It's a moot point these days because my Tacoma has an electronic brake booster that makes it easy to bleed the system, and only certain models have them.

 

[MikeF2316]

Think about what you just wrote for a minute...and the think about the weight of air vs any liquid, and finally the vertical separation of the master and slave/bleeder valve.

How about I just think about what I've seen?

Think about surface tension and tiny orifices. Especially when the reservoir is remote and shared with one of the brake circuits. Air prefers to go up, relative to the fluid. If fluid doesn't go through the orifice at the top fast enough to block the pipe and force the air down, then the air is just going to sit in the pipe while the fluid runs down beside it.

The best way is force it up from below. That way air move the way it naturally wants to. But I've had great luck with using my Motive bleeder dry, from above.

 

[duwem]

I have borrowed a motive, used it dry, flushed the whole brake system on my car. Had a spotter watching the reservoir, never got close to running dry. Topped it out after each corner. Ran it on each caliper till clean fluid came out. Pretty nasty stuff in the lines.

I made my own out of a menards sprayer, it was thick enough I could drill and tap the tank for a pressure gauge. But I couldn't get the cap I bought from autozone to seal. Might have to look into buying some caps from the Motive guys.

 

[928'er]

The best way is force it up from below. That way air move the way it naturally wants to.

Here's a link to a video of a method for bleeding a clutch system by pumping fluid up through the slave cylinder using a (new) pump oil can.

 

[CheezyRiderAZ]

Regardless of the possible air contamination possible with the Motive brake bleeder or any other when used wet, or to us it dry..........

I've been using a Mityvac Vacuum Pump.
It attaches to one bleeder screw, puts vacuum on that screw, and pulls fluid thru the wheel cylinder/ bleeder. The old fluid goes into a small reservoir cup that came with the Mityvac.
I can watch the clear hose attached to the bleeder for newer, clean fluid to start coming thru.
I do have to use it at each wheel, but I suspect that you must crack each bleeder with the Motive brake bleeder too.
I can use it by myself so no complaining from the wife about pumping the pedal (I don't have kids).
It works for me and the only chance for atmospheric contamination is when I check/ refill the reservoir after each wheel.

AND, it's only $40 at, I hate to say it, Communist Freight, I mean Harbor freight.

 

[kgorman]

Motive. Use it many many times in competition situation. Always dry. Works excellent.

 

[MikeF2316]

Here's a link to a video of a method for bleeding a clutch system by pumping fluid up through the slave cylinder using a (new) pump oil can.

I have to say, I've never thought of doing it that way.

 

[Schurkey]

Reverse-bleeding clutches would work very well.

Reverse-bleeding brake systems can create problems. Contaminated fluid--and the worst fluid is usually at the wheel cylinder--when pushed backwards through the ABS system can create ABS valving faults.

Reverse-bleeding of brakes should only be done when the system is CLEAN and EMPTY, or when the fluid has been flushed in the normal direction first, so that there's no contaminants to push back into the ABS system.

Keep in mind that all it takes to reverse-bleed a disc brake system is to push the caliper piston back into the bore. No special tool needed.

Of course, you'll have to safely/carefully remove excess fluid from the reservoir as needed.

In ALL cases of reverse-bleeding, the system must be final-bled in the normal direction. The bleeder screw is above the fluid port on wheel cylinders, calipers, and even on clutch slave cylinders. Therefore, reverse bleeding can easily trap a small bubble of air between the bleeder screw and the fluid port. Gravity bleeding in the normal direction as a final step removes this small bubble.

 

[928'er]

Reverse-bleeding of brakes should only be done when the system is CLEAN and EMPTY, or when the fluid has been flushed in the normal direction first, so that there's no contaminants to push back into the ABS system.

Nobody said anything about reverse bleeding brakes....

 

[ChevyEFI]

The master cylinder and pedal pressure bleed a system stronger than any hand pump.

Pressure bleeding by use of the master also will push fluid through an intelligently designed system in a way that dislodges air and moves it to bleeding points more effectively than other methods.

Mike, pressure from below could work, but you're not taking into account the master cylinders lacking well designed passage to assist in air escape, and again, less effective lower pressure pump.

The most effective way to clear garbage out is to let the fluid do the work. The more pressure the better. The most effective way to get air out is recirculating of the fluid. This can be accomplished by circulating fluid back into the reservoir and back through again. Oftentimes a barely cracked bleeder lets the system work like it has a one-way valve, or you need one-man bleeder screws, or a helper.

My mighty vac remains dusty.

 

[Schurkey]

Nobody said anything about reverse bleeding brakes....

The best way is force it up from below. That way air move the way it naturally wants to. .

Here's a link to a video of a method for bleeding a clutch system by pumping fluid up through the slave cylinder using a (new) pump oil can.

Yeah, someone did.

And then amplified by relating it to bleeding a hydraulic clutch.

pressure from below could work, but you're not taking into account the master cylinders lacking well designed passage to assist in air escape.

Something I completely overlooked. Thank you.

Many (most?) master cylinders on the vehicles I work on are tipped "up" in front. This aligns the pushrod with the brake pedal better than if the master were installed "flat". However, this also makes them prone to retaining an air bubble between the front of the cylinder and the compensating port between the cylinder and the reservoir. About the only way to remove that bubble is to level the master cylinder--either raise the rear of the vehicle, or disconnect the master from the firewall with the tubes still connected, and push the front downward (flexing the tubing). At that point, some light stroking of the master will push the air through the compensating ports.

 

[Qualitytools]

Here's a link to a video of a method for bleeding a clutch system by pumping fluid up through the slave cylinder using a (new) pump oil can.

Very Cool, I had not thought of that, i liked that Vid from BMP in Texas, as I have purchased BMW Parts from them before, very informative, Always learning something new I LOVE IT! Thanks for sharing