Audi S4 Brake Flush (2018+ B9 3.0L V6 TFSI) - 20K Mile Service - Part 3

[@St3rmTig3r]

very helpful on my 2018 SQ5 brake fluid replacement yesterday. Thank you!

[@tony8108]

Appreciate all the s4 content! Super helpful and I have some questions. I got the 2018 s4 recently at 15k kms and now I’m at 25k.. planning to do the maintenance at around 30k kms but wondering if my brake pads will need to be replaced or does the dealership kind of refreshed things when sold to me? Not sure when id need to do an oil change or brake flush either.. I get a little squeaking from the breaks at the start of the day driving

[@joshsheinis5968]

Amazing video! Just curious, where did you find the amounts that has to be removed from each caliper? I can’t seem to find it anywhere in the service manual

[@DmitrysGarage]

It's in the Maintenance volume of the factory service manual, it lists the per caliper capacities.

[@joshsheinis5968]

@@DmitrysGarage thank you for the speedy reply!

[@darksaigon]

Is it the same order of bleeding for a 2020 B9.5 A4 40?

[@jgdiablo70]

Nice video! Question: i see other people who remove old fluid from the master cylinder prior to starting the replacement. Your instructions doesn't mention this. Can you elaborate?

[@DmitrysGarage]

Sure, so you may need to remove some fluid if you are going to replace brake pads and have topped off fluid in the past. As pads wear down the fluid level will drop since the pads must travel out as they wear. Some people top off and if you want to install new pads you will have to push the caliper pistons out which will cause a topped off reservoir to overflow. Other people may have old fluid that looks nasty that they dont want to send through the lines. You might want to nearly empty the reservoir and fill with fresh fluid if thats the case. If you are keeping up with maintenance your fluid should still be fairly clean and pushing it through the lines until new fluid comes out is not a problem at all. In my case my fluid was still in great shape, there was no reason to not just shoot it through the lines.

[@Shulcyo]

@@DmitrysGarage How do you even remove old fluid from the tank when there's protective plastic filter that prevents dirt going in ? Think i see it yellow in your container. My SQ% has it orange. It's impossible to remove it ! I am also curious as to what happens if you drain your old fluid and just pour in new one without bleeding oil from brake calipers. Does that oil mixes with new one or does it permanently stays in caliper ?

[@salimsanchez89]

I thought the b9 cars required low viscosity dot 4 fluid. Or does it not really matter? I believe ate has a low viscosity version on thier 200 fluid

[@DmitrysGarage]

You are correct, it comes with a DOT4 LV fill. However, it's really a fairly marginal difference. DOT4 is fine unless you expect to operate in cold conditions where the thinner LV fluid will help when the brakes are cold. The downside of the LV fluid is that it boils at lower temperatures than the traditional DOT4. Overall though it's a very small difference and I wouldn't stress about using either one of them.

[@salimsanchez89]

@@DmitrysGarage okay, good to know. Thanks! I autocross my s4 a couple times a year and have a track event coming up next month. I was looking for a good quality fluid that was a good street/track compromise without going to race fluid that has a short change interval. I live in Florida so I don't think the LV specs are beneficial to me.haha I think I'll go with the type 200. Thanks!

[@coalieroller5663]

ATE SL6 is the DOT4 LV, but if you want high temp with low vis, DOT5.1 is your friend.

[@rickny1971]

Just curious -- if you have the Erwin factory service materials for the car, the section on brake bleeding in the service manual instructs you in the order you described - outer bleed screw followed by inner bleed screw.. But strangely, if you follow the instructions for brake fluid change in the Erwin maintenance manual, they instruct "Step 2 - Brake System, Bleeding and Filling: If there are two bleed screws per brake caliper: Bleed the inner bleed screw first and then the outer." -- do you think the order of this is critical at all?

[@DmitrysGarage]

Interesting. What model/year/market (i.e. NA, EMEA, etc...) car? I'm looking at B9 S4 manual for the US/NA market and interestingly the document contradicts itself once but not the same way yours does. Mine says to bleed the outer in every reference to bleeding except one where it says it backwards. I would assume this is just a typo. You do need to bleed both, I would bleed the outer one, I've always bled the outer first on calipers with multiple valves. It is funny that your text is different, i can't find that exact text in any of my docs.

[@rickny1971]

@@DmitrysGarage So, this is 2021 S4, US Market. In the Workshop manual, Edition 03.2019 Section 6.2 Hydraulic System, Bleeding -- it does say it in what both you and I believe to be the correct order.. But there is also a note at the end of that section in mine that says "Brake Fluid, Changing. Refer to ⇒ Maintenance ; Booklet 830 ;Maintenance Work; Brake Fluid, Changing" -- and it is in that Maintenance manual (which details all of the procedures for everything covered in the maintenance schedule - and I have it named as D4B805C61D2-Maintenance.pdf from when I downloaded everything from Erwin) -- that is where they reference it backwards.. Like you said - I'm going to assume they had a typo in that manual

[@rickny1971]

ALSO -- I forgot the main thing -- thank you for such a great detailed video!

[@DmitrysGarage]

@@rickny1971 Thanks, I'm glad you enjoyed the video. I think the issue is a typo like we both found.

[@lars2748]

Question: Is the bleeding bleeding order the same for an A4/A5?

[@JakesTech]

Have you found a link or PDF to a maintenance schedule for the B9 S4? I have a 2018 and can’t find anything.

[@DmitrysGarage]

Jake, Audi does it kind of differently. They have a per year cross-model schedule, it’s not a model specific pdf. Google “2018 Audi Maintenance Schedule - All Models”.

[@jgdiablo70]

Shop manual calls for 29psi. Does that make sense?

[@luiszubillaga1463]

YeH I read that too. But it seems high to me. Maybe I'll try 20.psi and see how it goes

[@salimsanchez89]

One more question, do I need an OBD tool to retract the electronic ebrake before I bleed the rears?

[@DmitrysGarage]

To bleed you won’t but to do pads you will.

[@geoffreyedmundson9928]

I have read you also need to bleed the ABS system, is this correct?

[@DmitrysGarage]

Only if you let the system run dry at the reservoir or replace relevant components. Otherwise generally the abs system does not need to be bled. You just bleed the lines normally and run all new fluid through.

[@Soloplayer08]

Would it be the same bleed order for a 2019 b9 sq5?

[@DmitrysGarage]

I would assume so, but always best to check factory manual. You can get couple of day pass to erwin, Audis factory documentation system. They have very handy searchable pdfs for your specific vin number. Definitely worth having those pdfs for reference ;-)

[@IainB]

From the Erwin manual, page 186. Bleeding sequence 1 - Outer left front brake caliper 2 - Left front inner brake caliper 3 - Outer right front brake caliper 4 - Right front inner brake caliper 5 - Left Rear Brake Caliper 6 - Right Rear Brake Caliper

[@imyourhuckleberry3369]

Brake fluid after 20K? Dang. Ze Germans aren’t messing around.

[@DmitrysGarage]

Yea the maintenance schedule is a bit aggressive on some things. Strangely they're doing 10k mile oil intervals on pretty thin oil (I'll be going more aggressive there) which I'm sure makes people feel like its a cheaper car to maintain, but then every other maintenance is pretty involved.

[@DmitrysGarage]

@@v____l I'll be doing UOAs on this engine too, will be interesting to see how it holds up. On my daily driver A4 (2.0 b9) I did take the 10k mile intervals and it was fine, but I also wasn't driving that car hard. With the S4 I'm finding myself in dynamic most of the time and having more smiles per mile than with the A4 which will of course cause more sheering. I'll start conservative and then see what kind of performance I get from the oil. I'd rather not waste oil that's still perfectly good, so if the oil looks to have life left I'm open to extending out that interval to 10K.