Panelhead

I know the cars are going to shorter service on brake fluid. Why? Lifetime automatic teams fluid and annual brake fluid?
When I started driving brake fluid was only changed when bleeding the air out of the system. This was drum brakes.
Changing the fluid at 30 km seems a waste. The oil Change interval in the wife's car is recommended at 24,000 km. surely brake fluid is good for 100,000 miles.

mishar

Brake fluid is hygroscopic. Water in it can evaporate on a high temperature creating steam with same effect as air bubbles. It's life is determined by age not millage. It should be replaced every 2-3 years. Some people would replace it every year and on racing cars they replace it before every race. It was so since hydraulic brakes were invented. We were just too poor to follow that rule.

MP4.2+6.0

Brake fluid wear has nothing to do with miles. It has to do with time, which is because it is hydroscopic--attracts water.

Audi interval is every two years regardless of miles. My Mini (BMW owned) is the same. More acute as a practical matter if you live (drive) in a more humid area vs. a dryer area.

Also, if you think the tranny fluid is really lifetime, good luck. I have specific reason to know..on the last two Audis. ZF says approx 60K miles for heavy/severe duty. It used to say that in all cases, but quietly changed it some years back. Ditto on oil changes at 24km. Yeah, my Mini can get there too with its (BMW) CBS system in theory--which is also game playing for "cost of ownership" calculation manipulation (used in car survey reporting stuff). But, I can't imagine running a high strung turbo engine out nearly that far; it gets changed on 5K-7.5K intervals.

If you run the brake fluid out 100K miles, don't plan on any aggressive driving where you might actually need the brakes to work to the level Audi spec'ed them. That works okay (as in, mediocre) for many "appliance" vehicles that are casually driven. But for enthusiasts, ask even C&D who embarrassingly stuffed a new Z into a track wall at 100+ when they suddenly cooked the brake fluid, essentially with no warning. They noted BTW that VW/Audi's boiling point is much more stringent than the relevant fluid Nissan used. If you own Audis' into the second or even third 100K mile cycles, you will also find periodic brake fluid changing is a good way to avoid hydraulic failures of wheel calipers, master cylinders, and in last 20 years or so, pricy ABS units.

In practical terms, w/ car now off dealer service, for me its pretty easy--I just do a fluid change with a brake pad/rotor service, which tends to come up every couple years anyway on end or the other.

Panelhead

Audi interval is every two years regardless of miles. My Mini (BMW owned) is the same. More acute as a practical matter if you live (drive) in a more humid area vs. a dryer area.

Also, if you think the tranny fluid is really lifetime, good luck. I have specific reason to know..on the last two Audis. ZF says approx 60K miles for heavy/severe duty. It used to say that in all cases, but quietly changed it some years back. Ditto on oil changes at 24km. Yeah, my Mini can get there too with its (BMW) CBS system in theory--which is also game playing for "cost of ownership" calculation manipulation (used in car survey reporting stuff). But, I can't imagine running a high strung turbo engine out nearly that far; it gets changed on 5K-7.5K intervals.
.[/QUOTE]

The info here is off topic, but helps me. I need to visit the mechanics who did the pads and rotors. I am sure some fluid was replaced.
My wife's BMW is seven years old with original brake fluid and transmission fluid. The oil was changed annually, she only has put 37K on it. The dealer offered to flush the brakes for 189.00. It seemed to be mileage triggered.
My daily driver has 55K and is a 2013 model. The dealer wanted to replace the brake fluid at 30k, the car was 8 months old.
But living in Houston, the humidity is 100% most of the time. All my vehicles need a good flush.

mishar

It's never off topic if it helps somebody.

JohnnyJ A6Q

PLUS 1

MP4.2+6.0

Also off to a different car lineage and older history, but the fluids and specs are the same across vehicles. Skim down to the graphs and then the discussion about halfway down the web page and you will get the import of it all, and a variety of data and studies to back it up.

http://www.mossmotors.com/SiteGraphi...luid_long.html

thxguy

Since we are talking about Brake fluid - are there any drawbacks or advantages to using a racing fluid in these S8's? I know that the boiling point is higher- but is it of any value for a road sedan (I will not be tracking a car like this)

MP4.2+6.0

Audi OE is already high boiling point, both dry and wet, above DOT 4 specs. The C&D article where they boiled the Nissan Z fluid big time pointed that out specifically. I have historically used ATe Typ 200 Dot 4 fluid, which is yet another notch above the Audi fluid boiling point wise. What ever the choice, in a non-race application the primary reason to get the boiling point up is to counteract the hydroscopic water build up; see the link in my prior post. If the fluid is higher spec to start with, then more margin for some deterioration in boiling point over time.

With SL fluids now widely out though (low viscosity at very cold temps--may be important for ESP and ABS), FWIW I am likely to shift that direction next. I do 2 year change cycles, and haven't boiled fluid or lost any hydraulic part since at least my 1985 Audi 5000 probably literally a million miles of family vehicle service ago.

CobraCommander

Buy the S8 and you won't regret it...I don't drive mine daily, but when I do drive her it literally is like dating Candice better known as Candi if you're nasty