TwinTurbo420

No listing in manual for 991.2 (MY2019 C2S)

For Macan, Porsche has every 2 years regardless of miles in service schedule. For 911, it is not mentioned.

I am ~ 1 month away from 2 year oil change & I tested % water & it is 0%.

I’m in a dry climate.

I have seen nothing re problems with brake fluid other than moisture content, which of course is an issue & the main reason to change it.

I have also heard that since brake fluid does not circulate, measuring water % at the brake fluid reservoir does not give you a true test of the moisture content at the calipers & elsewhere in the system.
It may not circulate but, I assume it mixes some.

Comments?

polobai

I believe it’s also recommended at 2 years for the 991.

SoCal C2S

My Indy does the moisture test and either replaces the fluid or says everything is OK....I tend to go three years based on the last 4 Porsche’s.

luv2sleep

The manual says 2 years but I think it's overkill. If you track it, you'll probably want to flush it more often. Mine is exactly 2 years old. I tested for water in the brake fluid and came out 0%. I'll give it another year and see.

LexVan

Set aside your brake fluid for a moment. Why is your oil 2 years old? That's a bigger issue.

LexVan

I don't think any of this kind of stuff is listed in the Owner's Manual. These things are listed in a separate thinner booklet dedicated to Maintenance Schedules and a place for the dealerships to put their service stamps. Maybe yours is missing? If it is, they are easy to pick-up on eBay.

Guards_Red_991

Lex, I think he meant "second oil change" which is on his second year of ownership. I could be wrong.

garfunkle

Brake fluid change frequency totally depends on usage. Testers are cheap. Test and it’s easy and cheap to change with a $100 investment in a pressure bleeder.

I’d still do every 2-3 years. Here’s the issue with water, it boils and evaporates which will let air into the system.

991carreradriver

This ^^^^ is only partially accurate. Brake fluid is hydroscopic (naturally attracts moisture). Overtime its H2O content as a percentage of fluid will increase due to ambient humidity. The brake fluid system is not air tight. The higher H2O saturation, the lower the boiling point of the fluid. If the fluid should boil as a result of heating the fluid through braking, the fluid becomes gaseous. The boiling process will create the gases and brakes will be compromised.
If one engages in regular spirit driving, track driving or similar driving it is advisable to change fluid every year. For example, I have taken readings of my fluid and ranged >1% but <2% H2O and found my brakes compromised (mushy) during heavy continuous braking. Brake fluid testers are good for information, but it all depends on the heat the system generates and the amount of H20 saturation.

Norge911

Porsche is very aggressive with their maintenance schedule especially for plugs and brake fluid flush.

if I track or drive very very hard 20 weekends per year in my 911 I understand. If you drive it like your Toyota Corolla most of the time and only so often get on it, is it needed?? You should be able to determine what is beat for you and your car.

for my Cayenne, never over 80, smooth acceleration and breaking, my maintenance schedule should be similar to a Lexus/BMW plan with plugs, brake fluid flush etc etc etc. every 4- 6 years pending the service. Extra service means $$$$$$ for dealers. I do ensure I do oil change per the warning in the dash for the Cayenne.
For my 911 I follow the Porsche schedule or even more aggressive if I track it

spiderv6

True, but for some weird reason the US cars "need" service MORE than the cars in Europe. Every 2 years or 20,000 miles in Europe. Every year or 10,000 miles in the US.

I never understood that.

LexVan

Different warranties.
Different fuels.
Different lawyers.

These 3 come to mind first.

spiderv6

That makes more sense

LexVan

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Tier1Terrier

I'm pretty sure that brake fluid changes are recommended by nearly all vehicle manufacturers every 2 years (not by mileage).