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Discussion Starter · #1 ·
Hi all. I've recently bought a 2013 V10 plus and am having some issues with the brake fluid.

It was changed at a garage using a pressure bleeder set to 2 bar but now the pedal doesn't anywhere near as solid as it did before the change.

The garage have carried out 2 more flushes in accordance with the latest guidance on erwin which has improved the pedal but it still doesn't feel right.

Anyone else had a similar issue?
 

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I've not done the brakes on my R8 yet, but I've had this on other cars. Sometimes, a good old fashioned approach of pump and hold on the pedal and then cracking the bleeder is what I find it takes to get the final pedal feel right after getting it 99% there with the pressure bleeder. I know this isn't the official procedure on many of the modern systems, but I've used pressure bleeders and vacuum bleeders and ultimately had to finish them off with a foot for that rock hard pedal.
 

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I‘ve used a pressure bleeder for years and zero issues On several high performance systems.
I ‘d bet your shop allowed fluid in master to get too low,might have to push fresh fluid through entire system
the power bleeder I use warns never to go above 20PSI or master can be damaged, previous one suggested 15psi as optimum.
 

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Also, looking at the manual I have:

Bleeding sequence
1 - Left front brake caliper
2 - Right front brake caliper
3 - Left rear brake caliper
4 - Right rear brake caliper
 

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Discussion Starter · #6 ·
Both nipples on each caliper have been bled and the sequence from the Adi workshop manual on erwin was followed including the pressure for the bleeder..

Brake fluid replacement isn't a complicated procedure which is why it's strange that it's not gone to plan
 

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Both nipples on each caliper have been bled and the sequence from the Adi workshop manual on erwin was followed including the pressure for the bleeder..

Brake fluid replacement isn't a complicated procedure which is why it's strange that it's not gone to plan
Was the outer one bled first?
 

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Also, looking at the manual I have:

Bleeding sequence
1 - Left front brake caliper
2 - Right front brake caliper
3 - Left rear brake caliper
4 - Right rear brake caliper
This is against all other guides for brake bleeding, I would do it in reverse order i.e. furthest caliper first.
 
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This is against all other guides for brake bleeding, I would do it in reverse order i.e. furthest caliper first.
+1 I have never seen/heard of anything but farthest first, including outside/inside sequence then work closer.One hydraulic system, pretty much same as another.
I'd guess manual typo.
 

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This is against all other guides for brake bleeding, I would do it in reverse order i.e. furthest caliper first.
+1 I have never seen/heard of anything but farthest first, including outside/inside sequence then work closer.One hydraulic system, pretty much same as another.
I'd guess manual typo.
This is from the Audi factory manual. I agree, it's completely the opposite from everything else, which is why I pointed it out. It is not what you would typically do, but I assume Audi has a reason for this. This is the sequence from Audi with or without the pressure bleeder. Attached is the page on manual bleeding of the system. I have also attached a .pdf of the specific pages for bleeding.

This is also the same method Audi publishes for my 2005 TT. I upgraded calipers all around on that car, and had a lovely bleed fest that was mind numbing. I started with a pressure bleeder (Motive) and ended up having to finish it off with my foot to get the pedal I wanted.

I'll also throw out that in the case of the TT, if you run the system out of fluid, you can end up having to use VCDS to cycle the ABS pump. I would assume you could do the same thing on the R8, but I have not dug into this side to verify it.



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This is from the Audi factory manual. I agree, it's completely the opposite from everything else, which is why I pointed it out. It is not what you would typically do, but I assume Audi has a reason for this. This is the sequence from Audi with or without the pressure bleeder. Attached is the page on manual bleeding of the system. I have also attached a .pdf of the specific pages for bleeding.

This is also the same method Audi publishes for my 2005 TT. I upgraded calipers all around on that car, and had a lovely bleed fest that was mind numbing. I started with a pressure bleeder (Motive) and ended up having to finish it off with my foot to get the pedal I wanted.

I'll also throw ought that in the case of the TT, if you run the system out of fluid, you can end up having to use VCDS to cycle the ABS pump. I would assume you could do the same thing on the R8, but I have not dug into this side to verify it.



View attachment 268831
I've always used a bleeder with a non return valve on the end of the bleed pipe, this is very useful when its a one man operation.
I've used it on lots of different cars including the R8 with no problems.
Just for information, when I first bled the R8 the outside bleed nipple on three of my callipers snapped off due to the threads being seized, presumably never having been loosened, if you try to bleed the brakes with the wheels on you cant reach the outer bleed nipple???
 

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I've always used a bleeder with a non return valve on the end of the bleed pipe, this is very useful when its a one man operation.
I've used it on lots of different cars including the R8 with no problems.
Just for information, when I first bled the R8 the outside bleed nipple on three of my callipers snapped off due to the threads being seized, presumably never having been loosened, if you try to bleed the brakes with the wheels on you cant reach the outer bleed nipple???
Just to be clear, I didn't mean to infer that pressure bleeders can't deliver a 100% solid pedal or that you have to follow up with a traditional pump and hold method to get a good pedal. I only meant in response to the OP's original question that I have used pressure bleeders and have had situations where mixing in a pump and hold routine in addition to the pressure bleeder is what ultimately delivered the rock solid pedal I was after.

Yep, bleeders with the check valve at the end of the hose are nice, especially for the one man show.
 

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According to my shop manual Audi calls for 2 bars of pressure (29 psi) for proper ABS flushing. I also just flushed my R8 and Q7 using 2 bars of pressure and the brake pedal feel was good for both, even though I am noticing the squeaking sound in the Q7's brake booster area, but that's a different story.

According to the OP, the shop flushed multiple times so air shouldn't be a problem.

I‘ve used a pressure bleeder for years and zero issues On several high performance systems.
I ‘d bet your shop allowed fluid in master to get too low,might have to push fresh fluid through entire system
the power bleeder I use warns never to go above 20PSI or master can be damaged, previous one suggested 15psi as optimum.
 

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Even my Q7 shop manual calls out for the same bleeding order as the R8. Perhaps that's how the ABS module and the lines are designed? Not sure.

This is against all other guides for brake bleeding, I would do it in reverse order i.e. furthest caliper first.
 
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I'm not quite sure I'm getting this!
Pressure bleeding? Car goes up on a two post lift with pressure bleeder applied, brakes are bled while wheels are still attached (see previous comment) I can see no benefit to this other than convenience and I assume that this is why dealerships employ this method.
Manual bleeding, although more time consuming, is my preferred method and when done correctly avoids air lock issues that are sometimes encountered with the pressure bleeding method.
The brake lines remain open when the car is in a static situation,(Ignition off) so the ABS has no involvement until activated by the electronic control module, which is activated by the wheel speed sensors etc:
Brake bleeding as always been in my experience, furthest from the master cylinder first, so as to ensure that new fluid is in the longest lines, this also ensures that the front brake system gets new fluid when bled.
There may be exceptions to this based 'brake by wire systems' but to my knowledge this does not apply to our cars.
Just my opinion.
 

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Discussion Starter · #16 ·
The garage managed to resolve the issue by following the audi workshop manual (including the strange bleed order) which recommended pressure bleeder plus 5 manual pumps of the pedal.

Actually took 10 pumps but the pedal is now perfect.
 

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Edit:

Went under Brake System in my shop manual, instead of the Maintenance section, and it does indeed say "Press brake pedal five times to assist bleeding procedure", whereas in the Maintenance (and I have 4 different versions, 2012, 2013, 2015, 2016) and none of them mention about pumping the brake pedal.

But glad you got that sorted out.

Which brake fluid did your shop use?

The garage managed to resolve the issue by following the audi workshop manual (including the strange bleed order) which recommended pressure bleeder plus 5 manual pumps of the pedal.

Actually took 10 pumps but the pedal is now perfect.
 

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When you bleed the brakes with the pedal you need to make sure you're not pressing down to far on the pedal or you can dislodge dirt and debris into your brake system. The piston in the master cylinder doesn't usually go down that far in the cylinder under normal stiff breaking. FYI

I've used the brake bleeder and brake sucker to push/pull fluid to each caliper.

Its always a good idea to turn the car on and make sure your pedal is normal with the ABS ECU is energized before you go out to do some fun driving.
 

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Dirt from where? It's a closed system, should be zero chance of dirt.
I am guessing frederickg is referring to contamination that can happen when filling the master cylinder reservoir with dirt around the cap, which happens.
 
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