I need some advice. I took my 02 A4 to the Brake Team to have them replace my rear pads. They requested to replace some of the caliper hardware so I agreed just to have everything taken care of.(260 dollars was the damage.) Then when I went to pick it up after it took them all freaking day I noticed on the receipt they flushed my brake fluid. So I confronted him about what fluid he used. He said they filled it with Dot 3. I proceeded to tell him that there is specific fluid for German cars and he begins to claim its all the same. He claimed that the only brake fluids were Dot 3 and Dot 4 and they’re all the same. I disagreed again and told him I’ve boughten specific fluid ( Pentosin - CHF 11 S) when I owned my VW Passat. He then says “Well, there is synthetic fluid but if you put that in it will ruin your brake system. So, am I ok to run Dot 3 since they flushed the lines, or am I screwed and should I tell him he screwed up? Then pay to have the line flushed again and replaced. Thank you for your advice.

 

In general DOT 3 and DOT 4 are compatible. DOT 4 has a higher boiling point and is a superior brake fluid. The Audi requires something better though.


Audi requires DOT 4 SUPER which has a boiling point of WET - 329F, DRY - 500F

Here is a quote from the Bentley manual
WARNING-
DOT 3 and standard DOT 4 do not meet the above noted specifications. The wet boiling point for DOT 3 is 284F while DOT 4 is 311F. The dry boiling point for DOT 3 is 401F with DOT 4 at 446F.




You need special brake fluid and DOT 3 def won't cut it. I recently used Valvoline SYN Power Full Synthetic High Performance brake fluid. This fluid is available at Autozone and has the required 500F dry boiling point.


Take the car back with some evidence/documentation (take your Bentley manual if you have one). He needs to now FLUSH the entire system to get all of that DOT3 out of it. It needs to be completely replaced with the high performance stuff. Running DOT 3 can be very hazerdous to your braking system especially over time as it begins to absorb moisture.

 

Audi requires Dot 4+ fluid. Do not use Dot 5, although Dot 3 will work. See previous comment about differences in boiling point

Pentosyn 11S is power steering fluid. Hopefully you didn't previously top up your brake fluid with it.

 

Thank you for the heads up. I'll do some more searching. As for the power steering fluid you are correct, that was my mix up and no I didn't use it in my brake line. While typing I happened to look over to double check the Pentosin and that was the first bottle I saw. Thank you again.

 

Yes you want to stick with a DOT4 fluid. DOT3 has too low of a dry boiling point. You can experience brake fade during spirited driving much sooner with this fluid.
We carry the Pentosin DOT4 which is the OEM compatible fluid. It's a perfect fluid for daily driving.

 

I've used NAPA DOT 4. While not officially compatable it seems to do the trick well. I have a whole gallon of the stuff....

 

i use ate super blue stuff

 

i use maple syrup