# Brake fluid flush...now brake pedal/master cylinder squeak/sigh sound



## VDoubleUVR6 (Aug 21, 2001)

Sorry for the length but I'm going to try and get the into out in the first post...

So doing the right thing and following the maintenance schedule to maintain the warranty, I performed a full brake fluid flush on my wife's 2019 Tiguan two weeks ago (first flush at the 3 year mark...also did the Haldex clutch fluid). I used a liter OEM VW dot4 class 6, iso...blah blah blah certified fluid from a local dealer along with about a half a liter of ATE SL.6 which has the same exact specs as the factory in a motive pressure bleeder bottle set to 12-13psi. 

About a week and half into that flush my wife noticed a slight squeak/sigh type sound when one gently operates the brake pedal say in a parking lot or pulling into the garage. A quick Google search shows this seems to be common with MQB platform vehicles (VW, Audi, Porsche Macan's) and BMW's (found one there too) when a higher temp fluid such as ATE 200 is used. Now some of those Google search results were forums and videos and some reported the sound went away when they replaced with OEM fluid. 

Started thinking that maybe that half a liter of ATE SL.6 fluid might be causing that noise so I bought a liter of OEM VW dot4 fluid from the dealer and did an entire flush yesterday....the noise remains. WTF!!

Dug a little deeper on the interwebs and I found a thread in the golfmk7 forum that one person said they tried multiple LV (low viscosity) including OEM and it continues. One said they switched to ATE SL.6 in their Atlas and the sound went away. Forums and videos below...






Brake Pedal Squeak/Sigh


But why does this happen is what I want to know. I would like to know for sure also. Whatever it was, it was annoying and it made me paranoid. Just flush all of it out and don't look back! :P



www.golfmk7.com















Brake pedal squeaking - Help needed - Rennlist - Porsche Discussion Forums


Cayenne 958 - 2011-2018 - Brake pedal squeaking - Help needed - Hi All, After a brake bleeding using Motive Power Bleeder with pressure 15 PSI (there were no issues with the bleed, no air Bubbles). the next day, the brake pedal squeaking (NOT the brake pad). I attached a video for how it sounds...



rennlist.com











Sooooo...anyone else having this annoying sound after a flush? What fluids are you using?

I presume VW branded brake fluid is just an aftermarket brand like Pentosin, Febi, etc (one person on page 1 of the golfmk7 thread stated they used Pentosin LV dot4 which caused the issue). 

In June I flushed my R32 with ATE SL.6 with no such issue and I'm tempted in ordering two 1 liter bottles and give her Tiguan a thorough flush to get the OEM VW fluid out. 

Thoughts?









Sent from my Pixel 7 Pro using Tapatalk


----------



## fat biker (Feb 16, 2001)

Low cost, zero risk move, not much effort.
What are you waiting for? Pull the trigger.
Get back to us, we may all learn something.

fat biker


----------



## OEMplusCC (Jan 27, 2013)

Yeah try OEM fluid if you think thats the problem but my guess would be that maybe the system was not bled properly? People switching fluids means they had to redo the flush and maybe bled the system correctly at some point.

How exactly are you bleeding? Do you pump the pedal before applying pressure with the power bleeder?

Sent from my Pixel 4a using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

fat biker said:


> Low cost, zero risk move, not much effort.
> What are you waiting for? Pull the trigger.
> Get back to us, we may all learn something.
> 
> fat biker


I know... Going to wait until later this week and see if temps had anything to do with this as it's predicted to be around 60 Friday. It was quiet for a little over a week and then the temps dropped here mid last week and feel like that's when the sound started. 

I'll report back

Sent from my Pixel 7 Pro using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

OEMplusCC said:


> Yeah try OEM fluid if you think thats the problem but my guess would be that maybe the system was not bled properly? People switching fluids means they had to redo the flush and maybe bled the system correctly at some point.
> 
> How exactly are you bleeding? Do you pump the pedal before applying pressure with the power bleeder?
> 
> Sent from my Pixel 4a using Tapatalk


Technically not switching fluids. The first go around it was mostly VW fluid mixed with ATE SL.6 fluid that has the same classification rating. Second time I did the flush it was an entire liter of VW fluid. Again from what I understand almost no car manufacturer produces their own fluid and it's just rebranded aftermarket...hence why some aftermarket brands are listed as OEM on parts websites such as CPI, ECS and FCP.

As far as procedure, I'm following the service manual for the Tiguan except I'm keeping the bottle pressure at a little lower PSI which is fine and it'll just a little longer to bleed. To answer your question, no I'm not pumping the brake pedal before. I'm also bleeding FL, FR, RL, RR...again per the service manual. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## gerardrjj (Sep 4, 2014)

I would say this is most likely a case of correlation rather than causation. 
The only ways I can thing a bleed would cause noise are:
a) fluid was spilled on the pad/rotor and has seeped into the pad changing the braking characteristictics
b) air in a line causing less braking force on one wheel.

a might be solved by thorough cleaning with brake cleaner spray and getting the pads nice an hot with some aggressive braking, basically the bedding process.
b would be another bleeding to resolve.


----------



## OEMplusCC (Jan 27, 2013)

gerardrjj said:


> I would say this is most likely a case of correlation rather than causation.
> The only ways I can thing a bleed would cause noise are:
> a) fluid was spilled on the pad/rotor and has seeped into the pad changing the braking characteristictics
> b) air in a line causing less braking force on one wheel.
> ...


I am not sure if I follow. The OP is experiencing a hissing noise coming from the brake pedal area as shown in videos attached in the original post. That would indicate that noise is being created somewhere at the pedal or master cylinder.

PS: Now I want to check my wifes Tiguan to see if it has this problem. I did brake fluid change in September but I dont drive that car much. I used Genuine VW/Audi fluid


----------



## VDoubleUVR6 (Aug 21, 2001)

OEMplusCC said:


> I am not sure if I follow. The OP is experiencing a hissing noise coming from the brake pedal area as shown in videos attached in the original post. That would indicate that noise is being created somewhere at the pedal or master cylinder.
> 
> PS: Now I want to check my wifes Tiguan to see if it has this problem. I did brake fluid change in September but I dont drive that car much. I used Genuine VW/Audi fluid


Thank you...was confused also.

And please if you get a moment...car running in park and gentle apply the brake on and off. If you cycle it quick it won't make the noise, just slowly on and off the pedal. 

For haha's since everyone loves pictures, attached is the 1 liter bottle. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## DoC0427 (Sep 16, 2019)

I wonder if the issue is related to the ATE SL.6 fluid you used. Though it is a DOT4 fluid, it’s “low viscosity”, sometimes called DOT4 + or LV. It’s about 1/2 the viscosity (thinner) than what would be called standard DOT4.

I have a very similar “squeak” that comes from the booster/master cylinder as well but only very occasionally so I didn’t think much of it until now and it started shortly after I flushed my brakes with this ATE SL.6 fluid.

I’m now wondering if the low viscosity provides perhaps less/different lubrication to the seals in the master cylinder which is causing the squeaking?

I’m very anxious to hear how your flushing back to the OEM fluid affects things. I’m sure the OEM is a standard DOT4 and not the low-viscosity DOT4+ but I could be wrong. When you do the re-flush, it may take a while for the new fluid to work it’s way to replace the “old” fluid around all the seals (where the squeak is probably coming from).

…just my thoughts on this!

Please do keep this thread updated with your results!

Cheers,
DoC


Sent from my iPhone using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

DoC0427 said:


> I wonder if the issue is related to the ATE SL.6 fluid you used. Though it is a DOT4 fluid, it’s “low viscosity”, sometimes called DOT4 + or LV. It’s about 1/2 the viscosity (thinner) than what would be called standard DOT4.
> 
> I have a very similar “squeak” that comes from the booster/master cylinder as well but only very occasionally so I didn’t think much of it until now and it started shortly after I flushed my brakes with this ATE SL.6 fluid.
> 
> ...


Just to clear things up...I've flushed the braking system twice in the last two weeks, first flush was 1L VW mixed with about .5L ATE SL.6 (extra because I was afraid I was going to run out) and the second flush was 1L VW only.

The VW branded bottles I used are labeled DOT4 Class 6 that conforms to FMVSS no. 116, SAE J1704 and ISO 4925 (seen in photo above) which is the same certifications listed in the tech sheets from ATE's website for SL.6...that's what is throwing me off...literally the same fluid! Link to ATE SL.6's tech sheet: https://www.ate-brakes.com/media/2320/ate_td007_dot4-sl6-web.pdf

To top it off the VW service manual calls for "VW 501.14" which the VW bottle lists...









I understand where you say "less lubrication" but I can also see the point of the need for low viscosity fluid especially for the electronic components within the braking system and them being subject to REALLY low environment temps. But from what I'm reading, others have used ATE 200 which isn't low viscosity and from the rip they're having issues with the noise...again in my wife's cars case, the timing seemed to be more inline with the temps dropping last week. With that said...low temps tend to thicken fluids which also goes to explain that some people from the reading stated they switched to a DOT5.1 fluid and the sounds went away AND DOT5.1 fluid is considered to be "very low-viscosity" fluid which would make more sense with colder temps to work better.

I'm sure its fine especially since I've done it twice with fluids meeting the requirements but its more annoying than anything when gently using the brakes. Hopefully like you said, maybe it takes a bit to work its way around the brake system though I would think the whole point of the flush is to replace the old fluid with new fluid. They're predicting mid 50's for Wednesday, Friday and Saturday so HOPING the sound changes on those days. I COULD also just take the car for a spirited drive and cook the brakes to heat the fluid up but I'll be patient and see what the warmer temps bring later this week.

Hoping to hear back from you guys to see if your Tiguan's are "experiencing" the same thing.


----------



## OEMplusCC (Jan 27, 2013)

Quick update. Took my wifes car for drive today and did not hear anything. But it was fairly warm close to 50F and raining. Will try to look listen for the sound in few days again. I have used the same OEM fluid you posted.

Sent from my Pixel 4a using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

OEMplusCC said:


> Quick update. Took my wifes car for drive today and did not hear anything. But it was fairly warm close to 50F and raining. Will try to look listen for the sound in few days again. I have used the same OEM fluid you posted.
> 
> Sent from my Pixel 4a using Tapatalk


Awesome... Thank you for checking!

Sent from my Pixel 7 Pro using Tapatalk


----------



## OEMplusCC (Jan 27, 2013)

VDoubleUVR6 said:


> Awesome... Thank you for checking!
> 
> Sent from my Pixel 7 Pro using Tapatalk


Well ... I was able to reproduce that noise this morning. As you described the noise is there when lightly pressing on the pedal, e.i. parking or maneuvering through parking lot.
So I am in the same boat as you now  and its definitely annoying.
I am going back to my initial theory that this has something to do with bleeding, not the actual fluid. I have always used genuine VW fluid and I have been bleeding brakes as per factory manual with a power bleeder(I do between 15-20psi). I even used quickjack, like you ... I know that part does not matter


----------



## VDoubleUVR6 (Aug 21, 2001)

OEMplusCC said:


> Well ... I was able to reproduce that noise this morning. As you described the noise is there when lightly pressing on the pedal, e.i. parking or maneuvering through parking lot.
> So I am in the same boat as you now  and its definitely annoying.
> I am going back to my initial theory that this has something to do with bleeding, not the actual fluid. I have always used genuine VW fluid and I have been bleeding brakes as per factory manual with a power bleeder(I do between 15-20psi). I even used quickjack, like you ... I know that part does not matter


Sorry?? LOL

It sucks now that we know it's there. It's just odd...many have said changing out the fluid helped in there case but they were using ATE 200 which isn't low viscosity. 

IF...IF warmer temps make it "go away" I'd almost put money on if that DOT5.1 fluid was used, it would "fix" this annoyance.

Again thank you!! 

I'll keep you all posted later this week with my "testing".

BTW, the Quickjack setup is awesome for lifting the car up evenly.... I'd love a two post but don't have the height in the garage for it. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## OEMplusCC (Jan 27, 2013)

It was pretty warm today ~58F and noise was there. I am going to remain stubborn and still insist this might be due to bleeding... not fluid . I might get another 1L of fluid and try again over Christmas holidays. But I am curious to see how your experiment turns out.


----------



## david99 (2 mo ago)

Hi Guys,

I'm on the same boat - I posted also on the golf forum so to recap. I have Tiguan 2017 - MY2018, and squeak started also after fluid replacement but about first month I wasn't focusing on that as I every time thought it is my wet shoe on brake pedal doing that noise then found it is brake pedal itself and since then it is driving me crazy. I changed fluid to original VW OEM DOT4 LV fluid replaced fully like 2 liters, after that once more time with VW OEM DOT 4 LV, then tried Ravenol DOT 4 LV and now I'm on Shell DOT 4 ESL with all those fluid pedal is still squeaking. Yesterday ordered Motul DOT 4 LV and also TRW DOT 5.1 ESP as last try. After that I'm afraid only replacement of master brake cylinder will solve this - or also booster could be the culprit really no clue. I have also used power bleeder at around 15 psi.

If you find something please update this thread I will do the same once will have something new.

Thanks,

David


----------



## VDoubleUVR6 (Aug 21, 2001)

OEMplusCC said:


> It was pretty warm today ~58F and noise was there. I am going to remain stubborn and still insist this might be due to bleeding... not fluid . I might get another 1L of fluid and try again over Christmas holidays. But I am curious to see how your experiment turns out.


Haha...I'm on the other side of the fence and still think its the fluid because the power bleeder is so simple and practically error proof if you never run out of fluid in the reservoir.

I'm tempted to skip ATE SL.6 and go right to ATE Super DOT5.1 since its backwards compatible with DOT3/DOT4, has the same certifications and works better in lower temps.


----------



## VDoubleUVR6 (Aug 21, 2001)

david99 said:


> Hi Guys,
> 
> I'm on the same boat - I posted also on the golf forum so to recap. I have Tiguan 2017 - MY2018, and squeak started also after fluid replacement but about first month I wasn't focusing on that as I every time thought it is my wet shoe on brake pedal doing that noise then found it is brake pedal itself and since then it is driving me crazy. I changed fluid to original VW OEM DOT4 LV fluid replaced fully like 2 liters, after that once more time with VW OEM DOT 4 LV, then tried Ravenol DOT 4 LV and now I'm on Shell DOT 4 ESL with all those fluid pedal is still squeaking. Yesterday ordered Motul DOT 4 LV and also TRW DOT 5.1 ESP as last try. After that I'm afraid only replacement of master brake cylinder will solve this - or also booster could be the culprit really no clue. I have also used power bleeder at around 15 psi.
> 
> ...


Hi David...Thanks for chiming in!

Would you be willing to skip the Motul DOT4 fluid and go right to the TRW DOT5.1? I'm curious about the DOT5.1 fluid as a few posted up in the GolfMK7 forum that they switched to Motul DOT5.1 and the squeak went away.

Also any of you guys noticed that the bottom side of the master cylinder reservoir cap has the TRW branding on it? AND another thing...at least here in the States, anyone question why the first fluid change should happen at the 3 year mark and then 2 years after that? I've read that the DOT5.1 has a longer service interval though the fluid manufacturers state to follow vehicle manufacturers service interval.

Edit: TRW makes a DOT5.1 fluid...ECS sells it and listed at "OEM" on their site... https://www.ecstuning.com/b-trw-parts/dot-51-brake-fluid-1-liter/pfb532~trw/


----------



## david99 (2 mo ago)

VDoubleUVR6 said:


> Hi David...Thanks for chiming in!
> 
> Would you be willing to skip the Motul DOT4 fluid and go right to the TRW DOT5.1? I'm curious about the DOT5.1 fluid as a few posted up in the GolfMK7 forum that they switched to Motul DOT5.1 and the squeak went away.
> 
> ...


Hi VDoubleUVR6,

Sure I could do that and go with 5.1 right away, thing is that Motul have only one 5.1 which have viscosity 900 and I ordered TRW 5.1 ESP - PFB750 which has lower viscosity around 700 but I hope lubricity properties will be better than DOT4.

Yes exactly my master brake cylinder is made by TRW specifically it states TRW 8719 and it is TRW PML480 which is sold out everywhere currently. Original VW part is the same but price is 4x higher.

David


----------



## VDoubleUVR6 (Aug 21, 2001)

david99 said:


> Hi VDoubleUVR6,
> 
> Sure I could do that and go with 5.1 right away, thing is that Motul have only one 5.1 which have viscosity 900 and I ordered TRW 5.1 ESP - PFB750 which has lower viscosity around 700 but I hope lubricity properties will be better than DOT4.
> 
> ...


I thinking the same with the even lower viscosity and lubricity properties like you said....very curious to hear about your results. I'm also hoping its just the fluid...just coincidental that the noise appeared after the flush and honestly don't think its a failing master cylinder. 

Thanks again for the info!!


----------



## david99 (2 mo ago)

Today performed flush with Motul DOT 5.1 and it is still squeaking. Tomorrow I will receive Motul DOT 4 LV and TRW DOT 5.1 ESP but I'm kind of already thinking that only fix will be to replace master cylinder or brake booster whatever of those two makes the squeak.


----------



## VDoubleUVR6 (Aug 21, 2001)

david99 said:


> Today performed flush with Motul DOT 5.1 and it is still squeaking. Tomorrow I will receive Motul DOT 4 LV and TRW DOT 5.1 ESP but I'm kind of already thinking that only fix will be to replace master cylinder or brake booster whatever of those two makes the squeak.


Wow that's not promising and quiet annoying... Fingers crossed. 

Are you pressure bleeding, vacuum bleeding or by foot/two person?

Sent from my Pixel 7 Pro using Tapatalk


----------



## OmegaVW (Feb 14, 2021)

.
If the reservoir got too low there could be a pocket of air in the system? Foot bleeding would be the to eliminate any possibilities.
.


----------



## VDoubleUVR6 (Aug 21, 2001)

OmegaVW said:


> .
> If the reservoir got too low there could be a pocket of air in the system? Foot bleeding would be the to eliminate any possibilities.
> .


If it did then yes but I'm sure we all kept a close eye on that to not allow that to happen. Even if air got in the system, any of the methods would work to get it out plus the need to cycle the abs pump which in this case (at least for me) isn't the case. Pressure bottle always had fluid, maintained 12-14psi and the level never changed in the reservoir. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## OmegaVW (Feb 14, 2021)

VDoubleUVR6 said:


> If it did then yes but I'm sure we all kept a close eye on that to not allow that to happen. Even if air got in the system, any of the methods would work to get it out plus the need to cycle the abs pump which in this case (at least for me) isn't the case. Pressure bottle always had fluid, maintained 12-14psi and the level never changed in the reservoir.
> 
> Sent from my Pixel 7 Pro using Tapatalk


If all else fails I recommend starting the vehicle and using the system to pump out fluid but it will be a two person job. As soon as the pedal hits bottom it must remain depressed while the screw is tightened. Fundamental perhaps as everyone seems to know the basics and have done the work but I've made those errors.

Unless the new fluid is foaming and assuming the noise is created by that there shouldn't be noise after the fluid change. Like strut and shock fluid going through the various stage of valves foam can be created so pressurized gas is designed into the system to keep it down. I don't know if and when that would occur with brake fluid but it's worth considering. The entire brake system is not under pressure and or at all time so air or foam can remain when introduced. 

Try calling the dealership or an indie. The VW braking system should be generic enough for any seasoned mechanic to have encounter such an issue.

.


----------



## OmegaVW (Feb 14, 2021)

.
In hearing the noise again in the videos I'm wondering if it could just be the brake pedal assembly itself. Depending on the method used if the pedal at anytime has to go all the way to the floorboard it would be the first time the pedal has gone that far down. Spray some silicone, not oil or grease of any kind into the entire area to see if something has been compressed, bound or shifted.
.


----------



## OmegaVW (Feb 14, 2021)

VDoubleUVR6 said:


> "car running in park" and gentle apply the brake on and off.
> 
> Sent from my Pixel 7 Pro using Tapatalk


.

With the engine off does it make the same noise at all using the various brake pressure and cycling methods?

.


----------



## VDoubleUVR6 (Aug 21, 2001)

OmegaVW said:


> .
> 
> With the engine off does it make the same noise at all using the various brake pressure and cycling methods?
> 
> .


Yes until the pedal pressure is built up then there is almost travel in the pedal and obviously no more noise lol

To me it sounds like the seals within the master cylinder rubbing the sides with "less" lubrication some how.

Sent from my Pixel 7 Pro using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

OmegaVW said:


> If all else fails I recommend starting the vehicle and using the system to pump out fluid but it will be a two person job. As soon as the pedal hits bottom it must remain depressed while the screw is tightened. Fundamental perhaps as everyone seems to know the basics and have done the work but I've made those errors.
> 
> Unless the new fluid is foaming and assuming the noise is created by that there shouldn't be noise after the fluid change. Like strut and shock fluid going through the various stage of valves foam can be created so pressurized gas is designed into the system to keep it down. I don't know if and when that would occur with brake fluid but it's worth considering. The entire brake system is not under pressure and or at all time so air or foam can remain when introduced.
> 
> ...


I spoke with the parts manager from a dealer I purchase parts from and he said he hasn't heard of it (owner of a Tiguan himself) but he said he left a note with the service dept (texted him yesterday but he's on vacation). He said the shop uses BG machine and BG fluid unless it's a paid VW maintenance then VW fluids.



Sent from my Pixel 7 Pro using Tapatalk


----------



## OmegaVW (Feb 14, 2021)

VDoubleUVR6 said:


> I spoke with the parts manager from a dealer I purchase parts from and he said he hasn't heard of it (owner of a Tiguan himself) but he said he left a note with the service dept (texted him yesterday but he's on vacation). He said the shop uses BG machine and BG fluid unless it's a paid VW maintenance then VW fluids.
> Sent from my Pixel 7 Pro using Tapatalk


.
Hope you'll get it worked out as it will be helpful for others also.
.


----------



## VDoubleUVR6 (Aug 21, 2001)

OmegaVW said:


> .
> Hope you'll get it worked out as it will be helpful for others also.
> .


So do I!! Like I said before....I'm sure it's perfectly fine, it's just super annoying when the volume is low on the radio and one is driving slow (parking lot, traffic, etc).

Sent from my Pixel 7 Pro using Tapatalk


----------



## fat biker (Feb 16, 2001)

Why did it take until now for me to think of this?
Mechanics Stethoscope.

If it makes the noise when the car is stopped and the brake is applied, you could hunt for the source of the noise with the stethoscope.
Very handy tool.

fat biker


----------



## PantyDropper (Oct 28, 2018)

I don’t think so it’s a fluid - matter, it must “how to bleed”, I did to 3 cars and it has been running like a champ even better on traction’s, pretty solid too! I used ATE dot4 SL6 ( 3 cans)* bleeding out all OE fluids! But I did carefully with just 10-12 psi ( Motive)* slowly, 15-20 psi personally for me is risky 
And probably I will do again next year to completely clear the old fluids, I believe there 5% left there
Ate dot 4 SL6 is pretty good for 2 years, I had issue with traction and brake1 pressure sensor(g201-g214) for a year but after flushing it’s gone, my OBD2 tell zero prob now than before flushing !


----------



## VDoubleUVR6 (Aug 21, 2001)

fat biker said:


> Why did it take until now for me to think of this?
> Mechanics Stethoscope.
> 
> If it makes the noise when the car is stopped and the brake is applied, you could hunt for the source of the noise with the stethoscope.
> ...


The noise is definitely coming from the master cylinder. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

PantyDropper said:


> I don’t think so it’s a fluid - matter, it must “how to bleed”, I did to 3 cars and it has been running like a champ even better on traction’s, pretty solid too! I used ATE dot4 SL6 ( 3 cans)* bleeding out all OE fluids! But I did carefully with just 10-12 psi ( Motive)* slowly, 15-20 psi personally for me is risky
> And probably I will do again next year to completely clear the old fluids, I believe there 5% left there
> Ate dot 4 SL6 is pretty good for 2 years, I had issue with traction and brake1 pressure sensor(g201-g214) for a year but after flushing it’s gone, my OBD2 tell zero prob now than before flushing !


So you used ATE DOT4 SL.6 with no ill effects on three VW's...? Tiguan's...? MQB platform vehicles...? and all is happy? Three cans per vehicle or one can per vehicle?

I too use a Motive bleeder 12-14psi (because as things age....) and again follow the service manual in direction from closest to furthest. 

Again...I did my mk4 R32 this past summer with ATE DOT4 SL.6 and the Motive bleeder and all is well including the clutch. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## PantyDropper (Oct 28, 2018)

3 cans in the motive but basically a can per vehicle because I did one by one and no more push than 12 psi each (10-12)*


Sent from my iPhone using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

PantyDropper said:


> 3 cans in the motive but basically a can per vehicle because I did one by one and no more push than 12 psi each (10-12)*
> 
> 
> Sent from my iPhone using Tapatalk


Gotcha...thank you. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## GregRob (Dec 16, 2020)

VDoubleUVR6 said:


> Sorry for the length but I'm going to try and get the into out in the first post...
> 
> So doing the right thing and following the maintenance schedule to maintain the warranty, I performed a full brake fluid flush on my wife's 2019 Tiguan two weeks ago (first flush at the 3 year mark...also did the Haldex clutch fluid). I used a liter OEM VW dot4 class 6, iso...blah blah blah certified fluid from a local dealer along with about a half a liter of ATE SL.6 which has the same exact specs as the factory in a motive pressure bleeder bottle set to 12-13psi.
> 
> ...


While the Tiguan is based on the MQB platform, the Audi Q5 and the Macan are based on the MLB platform which has a much more complex suspension system.


----------



## david99 (2 mo ago)

Hi All,

So my update tested with Motul dot 5.1 the day after it seemed to be better, after that done flush again with TRW dot 5.1 ESP after that it was again better, squeak has nearly gone after driving for while. Today I was checking car after it was sitting 2 days in garage and it is again squeaking like hell. So I already do not believe that any fluid will change this and it is simply bad master cylinder or booster.

Thanks,

David


----------



## david99 (2 mo ago)

Just to add I tried flush at 15 psi and also at 30 psi - 2 bars and it is still the same.


----------



## VDoubleUVR6 (Aug 21, 2001)

GregRob said:


> While the Tiguan is based on the MQB platform, the Audi Q5 and the Macan are based on the MLB platform which has a much more complex suspension system.


Thank you for the info...thought otherwise 

Sent from my Pixel 7 Pro using Tapatalk


----------



## VDoubleUVR6 (Aug 21, 2001)

david99 said:


> Hi All,
> 
> So my update tested with Motul dot 5.1 the day after it seemed to be better, after that done flush again with TRW dot 5.1 ESP after that it was again better, squeak has nearly gone after driving for while. Today I was checking car after it was sitting 2 days in garage and it is again squeaking like hell. So I already do not believe that any fluid will change this and it is simply bad master cylinder or booster.
> 
> ...


I wonder if you had left the Motul 5.1 in there would it have been ok but with swapping the fluids so often, it doesn't give it time move around fully in the master cylinder with the different types you've tried?

And by chance, have you tried bleeding by foot (two person method)?

Sent from my Pixel 7 Pro using Tapatalk


----------



## david99 (2 mo ago)

VDoubleUVR6 said:


> I wonder if you had left the Motul 5.1 in there would it have been ok but with swapping the fluids so often, it doesn't give it time move around fully in the master cylinder with the different types you've tried?
> 
> And by chance, have you tried bleeding by foot (two person method)?
> 
> Sent from my Pixel 7 Pro using Tapatalk


I think that ABS module is returning fluid back to reservoir when you start car - therefore the pedal softens and goes down so I think that there was enough time to circulate the fluid in system before swapping to trw 5.1 esp. No I was not able to try bleeding by foot as I do not have anybody to help me with that. I personally do not believe it would change anything there would be no air in system at all, I never ran master cylinder dry and also done bleeding currently with more than 8 liters of fluids in total.

If there will be something new please let us know into this thread I will do the same.


----------



## VDoubleUVR6 (Aug 21, 2001)

david99 said:


> I think that ABS module is returning fluid back to reservoir when you start car - therefore the pedal softens and goes down so I think that there was enough time to circulate the fluid in system before swapping to trw 5.1 esp. No I was not able to try bleeding by foot as I do not have anybody to help me with that. I personally do not believe it would change anything there would be no air in system at all, I never ran master cylinder dry and also done bleeding currently with more than 8 liters of fluids in total.
> 
> If there will be something new please let us know into this thread I will do the same.


Will do...thank you. 

Sent from my Pixel 7 Pro using Tapatalk


----------



## PaulO123 (Nov 15, 2018)

Don't be so damned cheap! Buy yourself a pressure brake bleeding bottle. They don't cost that much and you can start bleeding your brakes on a regular basis. Most manufacturers recommend every two years for a full brake flush.


----------



## david99 (2 mo ago)

PaulO123 said:


> Don't be so damned cheap! Buy yourself a pressure brake bleeding bottle. They don't cost that much and you can start bleeding your brakes on a regular basis. Most manufacturers recommend every two years for a full brake flush.


We all do it with pressure brake bleeder and doing fluid change on regular basis if you check previous posts. Despite that we have issue with sqeaking.


----------



## DoC0427 (Sep 16, 2019)

So I was looking around the interwebs and came across this. Admittedly nothing to do with Tiguan or even VW but the problem sounds the same and perhaps the resolution may be the same.









Brake Pedal Squeak Finally Resolved!!!!


Guys, I wanted to share a solution I found to the dreaded Lambda break pedal squeak on almost all our cars. In the past it has been said that it is a problem with the seals in the Master Cylinder and that changing the brake fluid to the newer Delco fluid with conditioners will help, however it...




www.traverseforum.com





If I get a chance I may try this on the weekend, though may try some silicone spray lube or spray lithium grease instead of WD40 (anyone have any other suggestions?). I wonder what access in the Tiguan will be like?

For what it’s worth, this sounds like a far more likely source of the squeak than anything to do with the brake fluid.

If anyone else gets a chance to try this please post your results!

Cheers…
DoC


Sent from my iPhone using Tapatalk


----------



## david99 (2 mo ago)

DoC0427 said:


> So I was looking around the interwebs and came across this. Admittedly nothing to do with Tiguan or even VW but the problem sounds the same and perhaps the resolution may be the same.
> 
> 
> 
> ...


Do not want to put down your optimism, but I tried all this even sprayed with wurth PTFE spray booster main shaft under the dust boot. Squeak is still there, was doing measurements with dB meter and also recorded sound by phone from inside car - in cabin and then oustide car - in opened engine compartment. Noise was much-much more strong in engine compartment this proves that it is not happening inside car - pedal mechanism at least in my case.


----------



## DoC0427 (Sep 16, 2019)

Perhaps then it might be coming from whatever seals are there between the booster and master cylinder? Unfortunately that’s probably a very difficult place to get to without disassembling it all. 


Sent from my iPhone using Tapatalk


----------



## david99 (2 mo ago)

I think it is coming from master cylinder itself and I'm planning to replace it after winter.


----------



## DoC0427 (Sep 16, 2019)

I was looking at it further on the weekend and with the help of someone in the car pressing the brake to make the squeak and looking/listening under the hood, I’m also thinking it’s the MBC now.

I wonder if using the pressure bleeder pushed some fluid behind a seal or something within the MBS where it shouldn’t be or something like that? Or it could be the ATE SL.6 that it doesn’t like that I used.

I’m going to try and flush a full litre of new OEM VW fluid through it just to see as that is easier than replacing the MBC for now. If that doesn’t solve it, then I’ll probably take out the MBS and disassemble it all, clean it up and put it back.

Last resort for me will be to replace the MBC but I think it’s an expensive part ($300? CDN) and not sure “squeaking” would be a warranty issue, particularly since I did the flush myself. They (dealer) would likely claim I messed it up somehow. Probably not worth the hassle… I could swap it out in probably 45 mins.

Cheers…
DoC


----------



## david99 (2 mo ago)

DoC0427 said:


> I was looking at it further on the weekend and with the help of someone in the car pressing the brake to make the squeak and looking/listening under the hood, I’m also thinking it’s the MBC now.
> 
> I wonder if using the pressure bleeder pushed some fluid behind a seal or something within the MBS where it shouldn’t be or something like that? Or it could be the ATE SL.6 that it doesn’t like that I used.
> 
> ...


I do not think MBC could be broken by pressure bleeding the same way it is done at dealership. Also do not think this is because of flud if LV fluid was used. I was doing fluid change myself with pressure bleeding and with original VW fluid and despite that I ended up with squeaking pedal so I really think this is kind of seals wear + fresh brake fluid issue. Yes you are right oem MBC is like 300-400EUR for me, while TRW PML480 which is 1:1 the same thing costs around 80 - 90 EUR but it is not available anywhere - sold out. If you will play with MBC please let us know results. Ultimate test would be definitely remove MBC and try press brake pedal if squeak will be still present then it is brake booster if it will be silent then it is MBC.


----------



## OEMplusCC (Jan 27, 2013)

david99 said:


> I do not think MBC could be broken by pressure bleeding the same way it is done at dealership. Also do not think this is because of flud if LV fluid was used. I was doing fluid change myself with pressure bleeding and with original VW fluid and despite that I ended up with squeaking pedal so I really think this is kind of seals wear + fresh brake fluid issue. Yes you are right oem MBC is like 300-400EUR for me, while TRW PML480 which is 1:1 the same thing costs around 80 - 90 EUR but it is not available anywhere - sold out. If you will play with MBC please let us know results. Ultimate test would be definitely remove MBC and try press brake pedal if squeak will be still present then it is brake booster if it will be silent then it is MBC.


+1 I also share the same opinion.
Also, to add another data point. I have not heard this nice for good week. I am not saying its resolved but for me it definetely happens only occasionally.


----------



## david99 (2 mo ago)

OEMplusCC said:


> +1 I also share the same opinion.
> Also, to add another data point. I have not heard this nice for good week. I am not saying its resolved but for me it definetely happens only occasionally.


How long are you after fluid replacement?


----------



## david99 (2 mo ago)

david99 said:


> How long are you after fluid replacement?


I see your previous post since September so like 4 months now.


----------



## OEMplusCC (Jan 27, 2013)

david99 said:


> How long are you after fluid replacement?


Since September 20 car does not collect lot of miles since its all city driving(lot of stop and go) approximately ~1500 miles


----------



## DoC0427 (Sep 16, 2019)

david99 said:


> I do not think MBC could be broken by pressure bleeding the same way it is done at dealership. Also do not think this is because of flud if LV fluid was used. I was doing fluid change myself with pressure bleeding and with original VW fluid and despite that I ended up with squeaking pedal so I really think this is kind of seals wear + fresh brake fluid issue. Yes you are right oem MBC is like 300-400EUR for me, while TRW PML480 which is 1:1 the same thing costs around 80 - 90 EUR but it is not available anywhere - sold out. If you will play with MBC please let us know results. Ultimate test would be definitely remove MBC and try press brake pedal if squeak will be still present then it is brake booster if it will be silent then it is MBC.


Sorry, I was not implying anything is “broken”. I agree pressure bleeding should be fine. I was only thinking that perhaps (I do not know) the seals inside the MBC have “dual lips” and possibly the space between the 2 lips is expected to be “somewhat dry” and possibly now has fluid there. I don’t know.

Again, I’m grasping at straws having never taken a MBC apart yet.

Such a weird problem and surprising there’s several of us here with the same problem. And it seems (from what I’ve seen in this thread) that everyone who is experiencing this, had the fluid flushed by pressure bleeding. I’m a supporter of pressure bleeding as well, just noting an observation is all.


Cheers,
DoC


----------



## david99 (2 mo ago)

Hi All,

Small update form my side. Today I have loosened and removed two nuts which are holding MBC on Brake Booster, then pulled MBC out from Brake Booster few centimeters - without disconnecting pipes. After that tried pedal and it was not squeaking at all even after a lot of presses, once I put MBC back in place squeak was again there. I think this also proves that issue is really with MBC and not with Brake Booster. I also noticed when whole car warms up squeaking is disappearing or is less noisy. So my next step in spring is really to replace MBC.

David


----------



## VDoubleUVR6 (Aug 21, 2001)

WHOA....almost forgot about this thread.

Sooooo no positive update from me...

I caved at the end of November and I bought 2 liters of ATE SL.6 from Amazon (with 2026 "expiration date" printed on the bottle) and used one full liter again on my wife's car on December 4th WITH no difference in noise as it sadly still there. The noise doesn't seem to phase her and the brakes feel fine and work as intended so I'm going to let it slide until the spring. I will need to do the rear pads and rotors as the not only the pads are really low but the rear rotors appear to be warped as I feel it in the pedal and seat of my pants when applying the brakes so maybe I'll do it again but the "old school" method of pedal bleed. 

By chance David (or anyone else for that metter)...have you tried two person pedal bleed instead of pressure bleeding?

OR I might try ATE's Super DOT5.1 fluid as they advertise 3 years on the change interval which lines up with VW's first change interval.


----------

