apoelistas

I just checked the recommended fluid interval change. It is 2 years. I think they take into account the worst case scenario depending on environmental conditions.

Regarding the brake fluid change it is a good idea to do the first at least, in order to flush and clean the pipe system. I would think that impurities would settle down where the brakes are. For the filter in the housing you could inspect it, or clean (if there are impurities on it) rather than changing the housing but I never tried to extract the filter.

Hope that you find the answer you are looking for.

superswiss

Yikes! You should do some research on brakes and brake fluid. There are various grades of glycol based brake fluids. The more performance oriented they are the more hygroscopic they get. I use race fluid in my RS5 for example, which needs to be changed annually and I can feel the degradation over time and the difference after a flush. Silicon based brake fluid has other drawbacks. For example the molecules allow for air to be absorbed which makes the fluid up to three times more compressible than glycol based brake fluid. Not what you want in a performance oriented car. Not sure where you measure the moisture content, but the problem with moisture in the brake fluid is that gravity causes it to collect down in the caliper where it then also causes most of the issues, including corrosion.

The scheduled maintenance of pretty much every Audi calls for a brake flush every two years. The first two are even covered under Audi Care.

Yoshimura

My car is like 30 months old and I completely forget to request brake fluid when my last service was done 2 months ago. Strangely, dealers didn't propose it.

I will have it done and I will try to de-glaze rotor.

Thanks for all the comments!

MP4.2+6.0

Yes I found same thing w/ dealer/service advisor. You affirmatively have to remind them a lot of the time since it is strictly by time, not miles. And in spite of some replies here about the water issue in fluid (which is real--ask C&D when they plastered the Nismo into the racetrack wall and tried to 'splain why it wasn't their fault)--I find a fluid bleed after a few years of use also improves pedal feel in general.

As an aside but to keep thread info cleaner, no, there is no inline filter in an Audi brake system either per another reply--that would be crazy. It is only in the non pressurized fill area under the cap above the reservoir to avoid loose stuff or bottle seals and such falling in by accident. Similar to washer fluid fill. Can be pried out if ever needs cleaning. Nothing to do with pedal feel.

Bob Petruska

I don't disagree with what you state, but I know quite a few Corvette club members that run......

Molykote® Silicone Brake Fluid is used in high performance braking systems
including high performance vehicles, racing vehicles, motorcycles, some
military vehicles and for applications that require FMVSS 571.116 DOT 5 or
conformance to MIL-PRF-46176B specification. These fluids are fully tested
and meet the Federal Motor Vehicle Safety Standard 116 DOT 5 and MIL-PRF-
46176B specification.
The Molykote® brand of specialty lubricants and fluids have a long history
in automotive braking applications. This silicone-based product is capable
of performing over wide temperature extremes and is hygroscope with low
water absorption over its lifetime. As a result the fluid resists corrosion due
to low water content, which is further augmented by anti-corrosion additives.
Additionally it has good compatibility with braking system components including
polymers, elastomers and paints. This combination of performance translates to
consistent brake performance and reduced brake fade.

I just talked to a friend that has a collection of vettes and he stated that he uses this brake fluid in all his vettes and has great performance on the street, nice brake pedal feel, and modulation.

I'm sure the companies can come up with a nice blend of something if needed at a reasonable cost.

Redd

I don't know if it was MolyKote, although I did get some Molykote bearing grease (great stuff) and Moloykote lubricant oil (basically mineral oil very heavily doped with fine moly dust) over 30 years ago from Dow Corning. Back then it was available to fleet operators who could track it down, and the Dow Corning DOT5 brake fluid that I got (directly from them) came with application notes proudly noting that it was the stock brake fluid on F18 fighter aircraft, or something similar. A little different from automotive applkcations, but I figured if it was good enough for that, it was good enough for me.(G)

Got a surprise the first winter I had it in the car. Among the other little differences (and that dissolved air makes it a little softer, all the time) the silicone brake fluid CONTRACTS IN THE COLD. So, first winter road trip in ~20F weather and the car cold soaking outdoors...and the brake light came on when I got in the car to go home. The fluid had contracted just enough to be down about one teaspoon in the reservoir. That's all it took to make the brake light go out again, but these little things...."Kids, don't do this at home" might apply.

Bob Petruska

I just did a little research and silicone brake fluid is a big NO-NO with ABS equipped cars, as the ABS unit cause tremendous aeration of the fluid.

My friend's corvettes are all 1963 - 1967, thus no ABS, silicone fluid prevents the corrosion of the super expensive multi-piston calipers.

Redd

Yes, I found that out when I looked into fixing the crude brakes on my Q5. The last car was well out of warranty before ABS systems were off the drawing boards. And while ABS ($2500 for the typical ABS controller alone!) might be able to outperform the average driver, the number of "didn't stop soon enough" accidents has INcreased since ABS was mandated. Apparently people think ABS is magic, so they just don't brake soon enough to anything to work.

I'm still not at all sure that ABS will *always* do better than an aware driver.

And that $3000+ that it may add to the average car price, sure would buy a lot of premium brake parts and top traction tires.

apoelistas

I only said that in the filter housing there is a filter (screen filter), which sometimes gets clogged if brake fluid does not get changed in the long term. That would create problems if it does with pressure applied when braking.


I NEVER SAID THERE IS AN INLINE FILTER. Anyway it is not important to discuss this.

MP4.2+6.0

Sorry for paraphrasing, or misunderstanding what is still faulty advice. I was gentler in first reply but you want to call it out. Quote:
Add to it words from just above: "That would create problems if it does with pressure applied when braking."

Your understanding or speculation, or whatever it is, is mistaken no matter the words or summarizing. Threads stay for posterity and I don't like to see other owners get confused somehow if not familiar with brake systems--my reference to keeping thread cleaner but not originally attributing. There is no "filter" between the master cylinder and braked components, and definitely nothing normally serviced. The (very ordinary) filter is in the reservoir above the master cylinder just as I said. If instead you mean that filter, it is then not in the hydraulic circuit in any way, so flat out not relevant to braking or OP's issue. Typically only components in pressurized portion of brake system involving fine passages will be in ABS unit, which hydraulically is essentially non-servicable beyond bolt in-bolt out. Horse flogged.