Jnosol

HELP!!!

I flushed by brake fluids using the dry pressure bleeding technique @ 12psi. New fluid is ATE TYP200 DOT4 Gold. Now my brake master cylinder is squeaking when pressed. I wonder if ATE TYP200 DOT4 fluid doesn't offer the same lubricant level as OEM DOT4 so it allows the piston's seals to have friction against the cylinder. It sounds like someone's cleaning the window with excessive force.

Anyone used ATE TYP200 on their 991? Anyone experienced squeaks from the master cylinder?

Any advice or comments here is appreciated. I hope it goes away after a week or so.

BradB

Yes, I've used ATE Gold and Motul 600 with no issues.

991carreradriver

+1

worf928

99.9% sure that Porsche-branded brake fluid is ATE typ200. The main difference is that the can is black and not blue.

Does the BMC have bleeder? Did you bleed the BMC after you flushed the brakes?

mtony

Did the reservoir ever get too low when you were bleeding? Does the pedal feel good when braking? The first thing I would do is bleed again, making sure the reservoir stays full throughout. You can also finish the job by doing a good old fashioned, pump the pedal bleed to see if the noise is gone.

Jnosol

BMC requires dealer to do, not required unless you're replacing your calipers/master cylinder/brake hose.

I'm very careful to never let the reservoir dip below between max and min line. Will wait for a week and re-do to see what happens. There are reports of ATE TYP200 making master cylinder squeaky, not Porsche though. I've had ATE TYP200 on my F80, no issues.

Duke I

No issues here either. I used 2 liters of the ATE Gold just to be safe -- just kept loading it in.

Jnosol

Thanks, I did 2 cans as well. The brake pressure feels so much better than before, but the damn squeak is driving me crazy. It squeaks when the pedal is all the way in. I'll give it a week.

ddolbi

This is my first post. Hello everybody. I'm having exactly same problem on my 2016 GTS as OP. How did you resolve the problem? Did ATE 200 is the culprit? I just did annual brake fluid flush with ATE 200 and have same symptom described in this post, squeak from the master cylinder or booster. Only on low speed stop there's squeak. Pedal feel and performance are fine. I thought Porsche rebrand ATE 200 as their OE fluid.

Jnosol

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.

ddolbi

Thank you for reply Jnosol. I have been using ATE 200 for several years on many cars and never had any problem. I did flush my BMW and Porsche on same day. BMW stops better than before. Was squeak seems coming from brake pedal? Mine sounds like it is coming from brake pedal even though clearly it's from either master cylinder or booster. By the way nice car and color. Mine is also white.

Jnosol

I used ATE 200 for all my BMWs in past, including F80 M3. Squeaks sound like it's from the pedals, but it's the master cylinder.

MJBird993

I had the same issue once, but on a Corvette, using ATE. New (rebuilt) master cylinder took care of the problem.

9914s

Me too on my Z06. After the rebuilt started using Castrol SFR problem solve. I also use it on my Carrera without any issues.

maverick1715

Hi! I have the exact same problem and exact 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. Brake feels good, performance is awesome, but squeaks like cleaning the windows! Did you solve the problem without having to replace the master cylinder? Replacing the master cylinder sounds extreme since the problem started immediately after the brake flush.