When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Dealer replaced the master cylinder, problem went away. I did the entire procedure as I've done every Euro car I've own before. Only at 12psi.
My hypothesis is ATE 200 not having the lubrication properties required which causes the master cylinder to squeak. It could be a coincidence.
Hi! I have the exact same problem and car, did brake flush with ATE 200. Took it back to my shop, did flush like 4 times, we did go through almost 5 Liters of ATE 200 and for sure there is not air. Brake feels good, performance is awesome, but squeaks like cleaning the windows when stopped or very slow speed! Replacing the master cylinder sounds extreme since the problem started immediately after the brake flush. Have you heard anybody else taking another step other than replacing the cylinder? Thanks!
After doing some more research after my post above I came to the conclusion that the current Porsche-labeled fluid is DOT4 LV (low-viscosity). The ATE 200 is not LV. I've flushed both 991s, the 981, and the Macan with Pentosin DOT4 LV with no 'squeaks' from the BMCs.
YMMV.
EDIT: The Porsche-labeled fluid for 'older' Porsches is, as far as I know, re-labeled ATE DOT4.
Thank you so much for your time and effort looking into that. Do you think leaving in there the ATE DOT4 for 2 years will do any damage other than the annoying squeaky noise? Im thinking of leaving it til is time to flush again.
Thank you so much for your time and effort looking into that. Do you think leaving in there the ATE DOT4 for 2 years will do any damage other than the annoying squeaky noise? Im thinking of leaving it til is time to flush again.
I can’t opine on that. The LV fluid is, apparently, what the stability control system (e.g ABS pump, etc) likes.
If it was me, I’d probably flush again soon, since the unknown for me, is the effect of non-LV fluid on the really expensive bits.
As for the BMC, I doubt it will hurt the seals. It would be informative if the ‘squeaky’ goes away after a flush with LV.
I can’t opine on that. The LV fluid is, apparently, what the stability control system (e.g ABS pump, etc) likes.
If it was me, I’d probably flush again soon, since the unknown for me, is the effect of non-LV fluid on the really expensive bits.
As for the BMC, I doubt it will hurt the seals. It would be informative if the ‘squeaky’ goes away after a flush with LV.
I really think the LV will fix the squeak. Again, this is my opinion but it makes sense. Seems that the ATE 200 (non LV) is not "thin" enough and doesn't lubricate areas where LV does. We used so much fluid believing we had air in the system and so much time keep test driving, removing center lock wheels, and keep flushing.. only to do it again. But seems that you may have give us the answer and we thank you for that. The next question would be is use 000-043-210-82-M210 or 000-043-210-82-OEM? Easier and way less expensive to get the M210.
I really think the LV will fix the squeak. Again, this is my opinion but it makes sense. Seems that the ATE 200 (non LV) is not "thin" enough and doesn't lubricate areas where LV does.
It is plausible and I tend to agree. If true, though, then it would follow that prolonged use of non-LV fluid will shorten the life of the BMC's seals.
We used so much fluid believing we had air in the system and so much time keep test driving, removing center lock wheels, and keep flushing.. only to do it again.
And with C/L wheels I can see why you don't want to do it again.
But seems that you may have give us the answer and we thank you for that.
The proof is in the pudding. Or, in this case the fluid. Maybe.
The next question would be is use 000-043-210-82-M210 or 000-043-210-82-OEM? Easier and way less expensive to get the M210.
Neither.
This is the fluid recommended for 2005 or newer Porsches:
It is plausible and I tend to agree. If true, though, then it would follow that prolonged use of non-LV fluid will shorten the life of the BMC's seals.
And with C/L wheels I can see why you don't want to do it again.
The proof is in the pudding. Or, in this case the fluid. Maybe.
Neither.
This is the fluid recommended for 2005 or newer Porsches:
Although that --^ picture shows the 'old' bottle. What you will find on store shelves now looks like this:
Bottom line: make sure the fluid bottle is specifically labeled "Low Viscosity" DOT4.
HTH.
While Im stucked on the forum waiting for your response I was doing my own researching and I found exactly the same information as you did. I agree with absolutely everything you said. I found this
Part numbers for the OEM fluid is 000-043-210-82-OEM. The Pentosin part number is 000-043-210-82-M210. We used 706232-M4. The common thing 000-043-210-82-OEM and 000-043-210-82-M210 have is the “Low Viscosity” formula. 706232-M4 is not Low Viscosity. Seems that Porsche uses 000-043-210-82-M210 and labels them with the black Porsche label and now it’s OEM and it’s twice as expensive.
Like you said, here’s where the confusion is. The 000-043-210-82-M210 which is LV (Low Visc.) on many retail stores including “Pelican Parts” shows the bottle with the wrong label. This Pentosin DOT4 comes as “SUPER DOT4” and as “LV DOT4”. The right product for the modern 991 is the "LV DOT4” with part number 000-043-210-82-M210 and not the "SUPER DOT4” which shows on retail stores ALSO as part number 000-043-210-82-M210. Also, the SUPER DOT4 is discontinued and been replaced with the LV DOT4, but many retailers still sell the old one.
This Pentosin DOT4 comes as “SUPER DOT4” and as “LV DOT4”. The right product for the modern 991 is the "LV DOT4” with part number 000-043-210-82-M210 and not the "SUPER DOT4” which shows on retail stores ALSO as part number 000-043-210-82-M210.
This is why I wrote "what is pictured" and "make sure the fluid bottle is specifically labeled "Low Viscosity"" as you can't trust web images or, necessarily, part numbers that are more than a day old.
Also, the SUPER DOT4 is discontinued and been replaced with the LV DOT4, but many retailers still sell the old one.
Maybe now. In October I sourced both 'normal' and LV for stock since I use the 'normal' for 928s and the LV for the 9[98]1s. At least with the 928s, I can always fall back to good old ATE.
This is why I wrote "what is pictured" and "make sure the fluid bottle is specifically labeled "Low Viscosity"" as you can't trust web images or, necessarily, part numbers that are more than a day old.
Maybe now. In October I sourced both 'normal' and LV for stock since I use the 'normal' for 928s and the LV for the 9[98]1s. At least with the 928s, I can always fall back to good old ATE.
The 'normal' fluid was part number 55.9520.101
You have no idea what you saved me from. It was driving me nuts and I was thinking of start replacing "stuff". Thank you very much. Im ordering as we speak 5L of LV DOT4 Pentosin. I am wondering if I should also flush the clutch (it's a manual). It's using the same reservoir as the brakes.
Don't thank me unless the LV flush makes the BMC stop squeaking.
Im ordering as we speak 5L of LV DOT4 Pentosin.
That should be enough LOL.
I am wondering if I should also flush the clutch (it's a manual). It's using the same reservoir as the brakes.
So, I was going to do this when I flushed the 991.1S MT's brakes. Unfortunately, I assumed it would be 'easy' and didn't check the WSM before I was in-progress. If you do the clutch flush according to 'the book' a special (stupid-expensive) tool (000.721.978.10) is required in order to avoid introducing air.
But, at least no PIWIS is needed.
I 'skipped' bleeding the clutch and bought the tool for 'next time' but 'next time' is in a few months. So, I can't report back on if the tool is really needed.
The tool is mostly a screw-valve to open or close the return line for the clutch and is supposed to be connected to the return line before bleeding. From reading the WSM (procedure 300107) the tool probably makes for a quicker and less 'hair-pulling' procedure. It might be enough to simply plug the return line while flushing the pressure line. On the other hand it might be hard to keep the return line plugged under power-bleeder pressure. On the gripping hand, if you are doing a two-man flush, maybe you don't need it. However, the WSM is very specific about manipulation of the clutch pedal during bleeding.
Somewhere on the interwebs giant PDF of an old version of the WSM is posted. You may be able to find the URL via a rennlist search.
find section 300107 and look at it and decide if you want to experiment with bleeding without the tool.
Since - unlike a 928 - the 991 (if I read 300107 correctly) has a return line from the clutch slave, it suggests to me that you may have pumped some of the non-LV fluid into the clutch lines via 'circulation.' Further reading indicates that the slave return line goes back to the fluid reservoir. So, yes, non-LV has been circulated.
Don't thank me unless the LV flush makes the BMC stop squeaking.
That should be enough LOL.
So, I was going to do this when I flushed the 991.1S MT's brakes. Unfortunately, I assumed it would be 'easy' and didn't check the WSM before I was in-progress. If you do the clutch flush according to 'the book' a special (stupid-expensive) tool (000.721.978.10) is required in order to avoid introducing air.
But, at least no PIWIS is needed.
I 'skipped' bleeding the clutch and bought the tool for 'next time' but 'next time' is in a few months. So, I can't report back on if the tool is really needed.
The tool is mostly a screw-valve to open or close the return line for the clutch and is supposed to be connected to the return line before bleeding. From reading the WSM (procedure 300107) the tool probably makes for a quicker and less 'hair-pulling' procedure. It might be enough to simply plug the return line while flushing the pressure line. On the other hand it might be hard to keep the return line plugged under power-bleeder pressure. On the gripping hand, if you are doing a two-man flush, maybe you don't need it. However, the WSM is very specific about manipulation of the clutch pedal during bleeding.
Somewhere on the interwebs giant PDF of an old version of the WSM is posted. You may be able to find the URL via a rennlist search.
find section 300107 and look at it and decide if you want to experiment with bleeding without the tool.
Since - unlike a 928 - the 991 (if I read 300107 correction) has a return line from the clutch slave, it suggests to me that you may have pumped some of the non-LV fluid into the clutch lines via 'circulation.' Further reading indicates that the slave return line goes back to the fluid reservoir. So, yes, non-LV has been circulated.
I'm going to thank you first because you took the time to explain everything in detail. Second, I'm 99% confident the squeak is because of the non-LV fluid I did put in; the system was perfect before the flush and I noticed the squeak right away after the flush. Some key points;
a) I am wondering if PIWIS is needed on a regular brake flush; it is my understanding that it actuates the ABS pump and flushes fluid off the ABS as well. If PIWIS is not needed then wouldn't the old fluid within the ABS pump mix with the new fluid in the reservoir once the ABS would be activated under hard braking?
b) If I would't flush the clutch, then non LV fluid would be mixed with LV fluid but percentage wise the LV fluid would be way much more (like 90/10%) than the non-LV. Driving for a year or two with the mix of the 2 fluids I'd --> assume <-- would be "fine"; and Eventually after a year or two with another new flush, LV fluid would be in all lines.
c) The reason of getting 5L is because I was thinking of doing 2 flushes (I know it's overkill but I want that stuff out) with the PIWIS which goes through a lot of fluid on each cycle. Then perhaps flush the clutch and then re flush the braking system with the old fashioned way (2 people press hold release etc). Overkill I know, I just don't want to have to redo it after I put the wheels back on. This would be the 4th time I'd take these wheels off within last 2 weeks, I feel mentally exhausted lol
d) It crossed my mind taking to the dealership but based on other people's posts, dealership would simply replace the MC which I don't trust them doing it (I have had extremely negative experience with P Dealership botching jobs)
a) I am wondering if PIWIS is needed on a regular brake flush; it is my understanding that it actuates the ABS pump and flushes fluid off the ABS as well. If PIWIS is not needed then wouldn't the old fluid within the ABS pump mix with the new fluid in the reservoir once the ABS would be activated under hard braking?
The WSM procedure for the 2-year scheduled brake fluid replacement does not require the PIWIS. As for the ABS pump, certainly some amount of 'old' fluid will remain after a flush, but how much all depends upon the internals of the pump and how it flows when not doing anything.
The WSM section (470107) for flushing the brake fluid specifies that the PIWIS is only required in the context of replacing the ABS pump. Thus, I opine that the PIWIS procedure is used to ensure that all air is flushed from a new pump.
Keep in mind that modern ABS pumps have two purposes: one is to relieve fluid pressure (as per the original purpose of ABS) and the other is to selectively increase pressure to one or more corners for stability control. Under the vast majority of on-public-road circumstances the ABS pump is doing nothing. If you've done nothing that would have activated PSM or the anti-lock brake functionality then I wouldn't worry about non-LV having gotten into any 'cavity' of the pump that won't be flushed with the basic procedure. However, I didn't stay at a Holiday Inn Express last night and I am not factory-trained (this assumes that that 'deep' level of understanding of the system is covered in training, which is not certain....)
Originally Posted by maverick1715
b) If I would't flush the clutch, then non LV fluid would be mixed with LV fluid but percentage wise the LV fluid would be way much more (like 90/10%) than the non-LV. Driving for a year or two with the mix of the 2 fluids I'd --> assume <-- would be "fine"; and Eventually after a year or two with another new flush, LV fluid would be in all lines.
There is a specific caution that non-LV DOT4 should not be used to top-up a system that requires LV. If the 991 clutch system didn't 'circulate' fluid - as it appears to do - then I think you'd be right about the mix.
c) The reason of getting 5L is because I was thinking of doing 2 flushes (I know it's overkill
Two flushes is probably a good idea for a reason I will present below.
but I want that stuff out) with the PIWIS which goes through a lot of fluid on each cycle.
If you have easy access to the PIWIS then I would definitely use it to completely flush the brake system.
After that, based upon what I think the 991's clutch hydraulics do, if you pump the clutch a bunch (say 20 times) you should circulate all the fluid from the clutch master, slave and lines back to the reservoir.
Then do a second flush of the brakes and reservoir. That should get you to 99-ish percent LV.
After looking at the WSM, I'm mildly convinced that the clutch hydraulics are 'self-flushing' and that actually bleeding the clutch isn't something that needs to be done on a schedule as long as brakes are done on schedule.
However, in your case, doing something to get the non-LV fluid out of the clutch is, I think, a good idea.
Then perhaps flush the clutch and then re flush the braking system with the old fashioned way (2 people press hold release etc).
More-or-less what I wrote above. Alternatively, do a two-man flush. Make your left leg tired on the clutch and then do a second two-man flush. That way you stand a good chance of getting it all done with only one C/L wheel R&R.
d) It crossed my mind taking to the dealership but based on other people's posts, dealership would simply replace the MC which I don't trust them doing it (I have had extremely negative experience with P Dealership botching jobs)
I can't imagine what a dealership would do in a situation like this. Regardless of what they would want to do, or what the Mothership might recommend, I too want the dealer (anyone other than me really) to touch my Porsches as little as possible. This is why I'm slowly, but steadily accumulating WSM sections and 9[98]1-specific tools.
02-01-2020, 11:48 PM
But seems that you may have give us the answer and we thank you for that. The next question would be is use 000-043-210-82-M210 or 000-043-210-82-OEM? Easier and way less expensive to get the M210.
