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  1. #1
    Established Member Two Rings
    Join Date
    Dec 27 2013
    AZ Member #
    137274
    My Garage
    2013 RS 5; 2015 GTI w/ PP
    Location
    Denver, CO

    RS 5 brake rotor and pad upgrade, now ABS kicks in sooner than expected

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    Hi all, I'm looking for some ideas or anything I may not have thought of yet...

    I replaced my RS 5 brake rotors (front and rear), with JHM rotors, along with new Carbotech pads. As I was bleeding the brakes afterward, I think I may have accidentally let the reservoir run dry, introducing air into the lines. So, I did a full flush/re-bleed again. Ever since, when it's cold, pedal feel is firm, but as soon as some heat builds up in the rotors and calipers, under moderate (not heavy) braking, the ABS will engage (on dry pavement, in a straight line).

    Thinking I didn't get all the air out, I re-bled again. It may have gotten slightly better, but it still happened. So, I re-bled AGAIN! (this time using a Motive pressure bleeder, previous times were the old fashioned way). And it's still happening. I don't know what else to do, any ideas?

  2. #2
    Established Member Two Rings MME1122's Avatar
    Join Date
    Mar 26 2016
    AZ Member #
    370854
    Location
    NJ

    If the pads bite harder than your stock ones they'll lock up the wheels easier, causing ABS to kick in. As the pads warm up they're probably grabbing harder. Do you feel like your actual stopping distance has gotten worse?

    Also what is the condition of your tires like?

    If you did actually drain fluid out of the ABS pump you need VCDS to do the priming sequence.

  3. #3
    Veteran Member Four Rings JamesRS5's Avatar
    Join Date
    Feb 27 2014
    AZ Member #
    149899
    Location
    Dubai

    Did you bed the pads and rotors in before giving the brakes a hard time? You need that pad material to transfer to the rotor for them to work correctly.
    If you had air in the system I would be expecting a soft pedal or long travel on the pedal, it doesnít sound like youíre experiencing this.

    Maybe try bedding them in correctly again and see how they feel but remember youíve upgraded your brakes so they will be working much more effectively than before so will need less effort. I had to learn how to slow the car without being too aggressive when I switched to the ceramic rotors, it completely changed how I use the brake pedal.
    I accept a Stage II tuned S5 is quicker than an RS5
    Doug convinced me
    He's also the reason I don't come here much

  4. #4
    Established Member Two Rings
    Join Date
    Dec 27 2013
    AZ Member #
    137274
    My Garage
    2013 RS 5; 2015 GTI w/ PP
    Location
    Denver, CO

    Thanks for the feedback, I appreciate it

    @MME1122 There are a lot of variables that changed during this swap-out, because I had also switched over from my winter to summer tires/wheels. That makes it a bit difficult to do a direct comparison on stopping distances, but I almost feel like it may have gotten a little worse. My summer tires are a bit worn, but they're not to the wear bars quite yet (I imagine later this season they will be). And I had read about the ABS sequence in VCDS, I did the "output test," are you referring to something else?

    @JamesRS5 I did bed them (10x near-stops from ~60 to 10, back to back; cool for 30 minutes of highway driving, lather, rinse, repeat), and I can visually see the rotors are a uniform gray color now, instead of the shiny silver. During the bed-in, this was happening, the ABS only kicked in the first, maybe second stop, then it just took more pedal travel. I do distinctly remember noticing that it wasn't stopping as quickly as I would've expected. Not sure if it was due to them not being bedded in, experiencing brake fade, or air or whatever issue in the brake lines wasn't applying 100% pressure on the calipers.

  5. #5
    Veteran Member Four Rings JamesRS5's Avatar
    Join Date
    Feb 27 2014
    AZ Member #
    149899
    Location
    Dubai

    More pedal travel when the brakes are hot is usually a sign that your fluid isnít up to the job.

    When I switched to ceramics all round, we removed all 4 calipers so the system was drained, it took 2 tins of Audi brake fluid to get the brakes working and no visible air from the caliper bleeds but the brakes still felt soft on the pedal, I bought another tin from Audi and the car sat over night. When we bled again the next day after the car sitting for 12 hours, air immediately came out of the bleed hoses on the rear calipers.
    Maybe you need to do the same, did you bleed front and rear? Let it sit for a time and try it again when the microscopic air bubbles have had chance to form big enough bubbles to bleed.
    I accept a Stage II tuned S5 is quicker than an RS5
    Doug convinced me
    He's also the reason I don't come here much

  6. #6
    Established Member Two Rings
    Join Date
    Dec 27 2013
    AZ Member #
    137274
    My Garage
    2013 RS 5; 2015 GTI w/ PP
    Location
    Denver, CO

    Yes, I bled all four corners. Used the traditional order of passenger rear, driver rear, passenger front, driver front. But I'm reading that for some VWs anyway, the recommended order is different. Anyone know by chance if the RS5 follows a different recommended order?

    The fluid I've been using is Motul RBF600, which has made the multiple bleeding exercises very expensive. I'm tempted to get some standard DOT4, do a VERY thorough bleeding (where I'm not concerned about the cost of wasted fluid), then push that out with more RBF600

    *Edit: when referring to driver vs passenger side, I'm assuming left hand drive. Not sure if they even made the RS 5 in right hand drive, but figured I should clarify

  7. #7
    Veteran Member Four Rings JamesRS5's Avatar
    Join Date
    Feb 27 2014
    AZ Member #
    149899
    Location
    Dubai

    I tried to use one of those pressure bleeders purchased from ECS but it was complete garbage and didnít work at all, we used the traditional method:pedal down, bleed open, bleed close, pedal up and it did the trick eventually.
    Itís a tough call, personally Iíd just run another 500ml of the RBF600 through it rather than switching back to regular and then back to the 600.

    Yes some of those small villages outside of the US had RHD RS5 since 2010
    I accept a Stage II tuned S5 is quicker than an RS5
    Doug convinced me
    He's also the reason I don't come here much

  8. #8
    Established Member Three Rings Ape Factory's Avatar
    Join Date
    Jun 24 2017
    AZ Member #
    401666
    My Garage
    RS5/Infiniti QX70S stormtrooper
    Location
    San Antonio, TX

    The Motive bleeders really work well. I have one and have used it successfully many a time. They work like a charm but I always find it takes at least three 500ml bottles and you'll have a bit left over. It really does require being anal retentive and bleed over and over again. Sometimes you can tap on the caliper with a rubber mallet to help force bubbles to the bleed nipple. I'll usually go around each of the four calipers twice just to be sure. Make sure to order one with the right cap.
    https://www.motiveproducts.com/colle...r-bleeder-kits

    I'm partial to Motul 5.1 as it's designed for ABS systems and flows through the tiny valves easier than other brands. If you're tracking, there are other offerings which'll withstand higher temps better.
    2013 Audi RS5 Misano Red, 20x10 Klassen ID M10/AWE Tuning Touring Exhaust/Eventuri Intake/Bilstein PSS10/H&R Sways/STERN Upper Control Arms/CR-15 reinforcement bar/ECS Stainless Steel Brake Lines/Apikol Rear Diff Bushing/ECS rear diff inserts/ECS front end links/034 Motorsports subframe inserts/034 Rear End Links/Tranny insert/E-code head & tail lights/Black Lip Spoiler, Red Trim Start Button, black emblems/VCDS.

  9. #9
    Established Member Three Rings Ape Factory's Avatar
    Join Date
    Jun 24 2017
    AZ Member #
    401666
    My Garage
    RS5/Infiniti QX70S stormtrooper
    Location
    San Antonio, TX

    Forgot to ask, what tires are you running? They have a massive effect on threshold braking.
    2013 Audi RS5 Misano Red, 20x10 Klassen ID M10/AWE Tuning Touring Exhaust/Eventuri Intake/Bilstein PSS10/H&R Sways/STERN Upper Control Arms/CR-15 reinforcement bar/ECS Stainless Steel Brake Lines/Apikol Rear Diff Bushing/ECS rear diff inserts/ECS front end links/034 Motorsports subframe inserts/034 Rear End Links/Tranny insert/E-code head & tail lights/Black Lip Spoiler, Red Trim Start Button, black emblems/VCDS.

  10. #10
    Established Member Two Rings
    Join Date
    Dec 27 2013
    AZ Member #
    137274
    My Garage
    2013 RS 5; 2015 GTI w/ PP
    Location
    Denver, CO

    Thanks guys,

    I did recently get a Motive with the "european cap (0100)," which fits well. I only pumped up to 10psi because I wasn't sure what the car's system could handle, and didn't want to damage anything. Today, I subscribed to erWin, and found out that it can handle up to 2 bars (~30psi). Also, bleed order is the reverse of what I've been doing. It says to start at the wheel closest to the ABS module, and work toward the farthest. So, I'll give it another go with the higher pressure.

    I do track it, but only once or twice per year. So far, the RBF600 has held up for me, and it's relatively reasonable on cost. Tires are still OEM: Toyo Proxes T1 (A0), which still outperform my skill level on the track :P

  11. #11
    Established Member Two Rings
    Join Date
    Dec 27 2013
    AZ Member #
    137274
    My Garage
    2013 RS 5; 2015 GTI w/ PP
    Location
    Denver, CO

    Update: I re-bled yet again, extremely thoroughly this time. The pedal feels better, and more consistent, even when the calipers are warm now. But I can still invoke ABS seemingly more easily. At this point, I'm going to consider it "normal," and a difference in the braking characteristics of the new rotors and/or pads. I do think I had some air in the lines before, which exacerbated issues.

    Thank you once again for the feedback!

  12. #12
    Established Member Three Rings Ape Factory's Avatar
    Join Date
    Jun 24 2017
    AZ Member #
    401666
    My Garage
    RS5/Infiniti QX70S stormtrooper
    Location
    San Antonio, TX

    When it's time, switch to Michelin Pilot Super Sports or Pilot Sport 4S tires. I'd also check your alignment and tire pressure to make sure it's optimal as all three will have a profound effect on braking. Especially with a car as capable as the RS5. Your tires are most likely the weak link at this point.

    Dusty roads and pavement type obviously come into play as well. It's been a while since I've been in Colorado but from what I remember, the state uses pretty grippy asphalt.
    2013 Audi RS5 Misano Red, 20x10 Klassen ID M10/AWE Tuning Touring Exhaust/Eventuri Intake/Bilstein PSS10/H&R Sways/STERN Upper Control Arms/CR-15 reinforcement bar/ECS Stainless Steel Brake Lines/Apikol Rear Diff Bushing/ECS rear diff inserts/ECS front end links/034 Motorsports subframe inserts/034 Rear End Links/Tranny insert/E-code head & tail lights/Black Lip Spoiler, Red Trim Start Button, black emblems/VCDS.



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