Jack F

Please report back. Inquiring minds NEED to know. 🤪

BOPE

I sent the query to Autel this AM and will revert with their response as soon as I get it.

Jason

AdamSanta85

I could have sworn this ABS bleed feature is in the ICarSoft 2.0 menu... I will double check when I change my oil this weekend.

Quadcammer

Is this an ocd thing? The fluid in your abs is fine. Flush the sucker with the motive and you will be just fine.

BOPE

Thanks; I sent an email to Autel this AM but have not heard squat.

Jason

Sidvicious7

Did you email Chris Moore at Autel?

--
Technical Support | Autel North America
Office: 631.923.2620
Fax: 631.357.3304
Email: CMoore@autel.comCMoore@autel.com | Web: www.autel.com
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BOPE

No, I simply used the email address on the Autel website, which is: sale@auteltech.com. Thanks for the additional contact info; I'll give it a try.

Jason

plenum

Curious what the concerns are with flushing / replacing brake fluid without exercising the ABS? I mean, to be thorough and for those with OCD I get the reason for it - but for majority of everyone out here a simple bleed etc. is sufficient. I've done this hundreds of times over the years on ABS equipped vehicles including multiple 911's and have not once had any side-effect of not using an electronic tool for the ABS valves.... For a street car or even one that is tracked occasionally it can't be that significant of an issue.

worf928

This——^

AFAIK, Brake fluid doesn’t ‘go bad’ from use in terms of hydraulic properties (unlike motor oil that does ‘go bad’ from use due to the operating regime.) Brake fluid is changed to get rid of the moisture that it absorbs. New (dry) fluid will quickly suck the moisture out of any remaining old (wet) fluid via diffusion as long as there’s any contact area between old and new fluid.

And this is why I asked about the design of the ‘guts’ of the modern Porsche ABS pump.

Furthermore, the posted video was all about getting the air out of the ABS pump not about routine fluid changes. Don’t do anything to introduce air to the brake hydraulic system and you won’t have air in the brake hydraulic system.

BOPE

You got it!

Hence my query for a tool that will get rid of moisture laden brake fluid that is TRAPPED in the ABS circuit. Based on my investigation of the workings of an ABS system, the circuit contains a pump, check valves, electrically actuated directional control valves, an accumulator and perhaps an orifice and damper. The problem is that many of these components, including the valves and pump, are isolated from the "normal" braking circuit. Over a period of time the moisture in the trapped fluid can and will damage these more or less sensitive components, which are probably manufactured from carbon steel that will easily rust in the presecne of moisture.

I don't understand resistance to not changing/flushing ALL the fluid, especially if a complete flush of the ABS circuit is easy to do with a tool that cost less than USD 200. Put it another way, if you took your car to a shop for a brake flush and the choice was: "Complete" or "Partial" brake fluid flush which would you choose? I get the impression some folks would say: "I'm non--OCD--proud, so I'll take the Partial flush!

Jason

worf928

Yeah... but *how* isolated are these various nooks and crannies? You never answered my initial question. Are they 100% closed off? Or is there any fluid contact whatsoever?

The fluid gets ‘moisturized’ because it literally sucks moisture out of the air through the external seals. I have serious trouble believing that the guts of the ABS hydraulic unit are better sealed from the fluid than are the external seals.

So, until someone posts pictures of a dissected 9[98]1 hydraulic unit (or design drawings) that show that there are cavities 100% closed-off from fluid wherein the only viable ‘moisture solution’ is either activation during flush or allowing diffusion to work through internal seals, I’m not going to get excited about calls that “the brake fluid sky is falling.” Even then, frequent flushing (yearly) will keep the moisture down in all of those 100% closed-off cavities.

BOPE

I haven't heard anyone say that "the brake fluid sky is falling":

No one will think less of you for not flushing the ABS circuit.

Attached is a hydraulic control schematic of a generic ABS circuit. The configuration of the vales are shown in the "normal braking" mode and as you can see, the release valve, pump and other bits are isolated.

Personally, I would like to exercise the ABS system to release the trapped fluid and get a more thorough brake flush.

But if you are content flushing the brakes using conventional means, then do it; I'm not trying to persuade you otherwise.

Jason

worf928

Quite the contrary. I have no evidence that suggests that not-flushing the ABS machinery is deleterious over the long term.

Certainly, if you have easy access to a tool that will command the ABS flushing then there's no reason not to do it while you have everything already 'out' and hooked-up for flushing.

However, in my opinion, there's also no reason to be paranoid or fearful of just flushing the brake fluid without doing the ABS as per the WSM procedure. And that is the point I was/am trying to make: flush it if it's easy for you, but don't lose sleep if it isn't or if you have to pay your dealer an extra $100 or $200 to PIWIS the flush. (Not that I would trust any service provider to not just take that money and run... I'd want a picture of the tool hooked up and activated...)

That diagram really doesn't provide sufficient detail. Without taking a 9[98]1 pump and dissecting it we can only make assumptions. In this case my assumption is that the sealing of brake fluid in valves, chambers, and the pump is far less effective than the brake system's external seals. Why? Because it doesn't have to be as effective. If that assumption is true then new brake fluid introduced during 'normal' flushing will pull the moisture out of the brake fluid inside the hydraulic unit with a matter of weeks if not days. The total volume of fluid in the hydraulic unit is a fraction of the total volume. If one changes the brake fluid every two years as per Porsche's schedule then the little bit of moisture left in the hydraulic unit isn't an issue in my opinion.

feldgary

Regarding ABS flush, Durametric was able to do this on pre 991 but is no longer supported on newer models....YET. I contacted Durametric and was told it may come later as an updated software release. Keeping fingers crossed it happens. Until then I will take it to my indy or dealer or just do the partial flush often myself.

BOPE

Thanks for the note on Durametric's ABS flush capabilities. I contacted Autel Sales and Chris Moore with Autel regarding the capabilities of their tool, but unfortunately have not heard squat.

Jason