# Brake bleeding sequence...



## CapeTownTT (Apr 11, 2013)

Hi guys,

I know this has been covered, but I can't seem to find what I'm looking for.

I will be replacing all the brake fluid on the TT and will also be bleeding the master cylinder and abs pump with vagcom.

My question is, in what order to do this? Calipers first, then master cylinder, then the pump? Or?

Thanks in advance guys!

Greetings from a cold Cape Town!


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## alexgreyhead (Oct 12, 2015)

I'm planning to do this shortly. The procedure I'll be following is...

- Use VCDS to bleed ABS pump (with the pressure bleeder on the reservoir for good measure)
- Bleed master cylinder's two nipples
- Front-left caliper (closest to ABS pump)
- Front-right
- Rear-left
- Rear-right (furthest from ABS pump).

For steps 3 to 6, I'll be pulling 300ml fluid from each caliper.

Then start the engine and check the pedal travel. If still soft, repeat the whole procedure again up to a total of 4x. If still soft, it's time to call a garage 

*DO NOT* allow the reservoir to run dry - if you get air in your ABS pump (like I did) it can be a nightmare bordering on impossible to get air out of the system. The Golf Mk4/TT Mk1 braking system is horrid for suffering from trapped air which can be a bastard to remove...

ps Ideally, get a pressure bleeder - apparently you can use it with the VCDS bleed process, although you'll definitely need an assistant. I have the Sealey one with a reservoir and it's been a lifesaver.

pps A set of speed bleeder nipples might be worth investing in - brilliant things 

/Al


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## David C (Apr 15, 2013)

As the master cylinder is the first point after the reservoir, I would have thought that would be the first thing to bleed.


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## Hoggy (May 8, 2002)

David C said:


> As the master cylinder is the first point after the reservoir, I would have thought that would be the first thing to bleed.


Hi, I was always taught front right first & rear left last. Nearest to M/C & working to furthest away. 
Bentley states front left first because as it's written for left hand drive cars & the M/C will be on the left.
Hoggy.


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## alexgreyhead (Oct 12, 2015)

I... thought the bleed process is to start with the wheel closest to the ABS pump, if fitted, hence front-left, as (I think) the ABS pump is in the same location on all models regardless of driver side?

I could be (am probably) wrong...

Edit: this how-to from the other (Trumpier) side of the pond seems to show the ABS pump in the same location (inside of the left strut turret) as on our RHD cars.

/Al


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## Hoggy (May 8, 2002)

Hi, Haynes is more confusing. 
Mark 20 IE system :? , right hand rear 1st , left hand front last
Mark 60 system :? , left hand front 1st, right hand rear last.
I've never bled the TT but I know many have problems getting a good pedal after bleeding.
Hoggy.


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## alexgreyhead (Oct 12, 2015)

Hoggy said:


> Hi, Haynes is more confusing.
> Mark 20 IE system :? , right hand rear 1st , left hand front last
> Mark 60 system :? , left hand front 1st, right hand rear last.
> I've never bled the TT but I know many have problems getting a good pedal after bleeding.
> Hoggy.


Interesting. Mark 20 & 60 refer to the model of ABS pump?

I found a number of people over on the Mk4 Golf TDi forums who have gone to the trouble of changing their Mark 20 ABS pumps for Mark 60 models for better performance, so there's presumably a significant difference in how they operate internally - I wonder if that would explain the differing bleed procedures?

/Al


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## David C (Apr 15, 2013)

alexgreyhead said:


> I... thought the bleed process is to start with the wheel closest to the ABS pump, if fitted, hence front-left, as (I think) the ABS pump is in the same location on all models regardless of driver side?
> 
> I could be (am probably) wrong...


As each wheel has a separate line from the ABS unit I don't think it makes much difference unless there is routing inside the ABS unit which makes a sequence better.
Most cars don't have bleed points on the master cylinder, so that generally doesn't get mentioned, but the TT does.

Pre ABS it was common for shared lines down the car, so sequence was more important.


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## alexgreyhead (Oct 12, 2015)

Aye, Shed 1 (a Mk3 Fiesta) had split FL-RR, FR-RL lines coming off the MC. The only driver feature it came with was understeer - no ABS, central locking, leccy windows or power... [smiley=bigcry.gif]

So... Why do we have to bleed the wheels in a certain order? Is this just unfounded VAG witchcraft...?


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## David C (Apr 15, 2013)

alexgreyhead said:


> Aye, Shed 1 (a Mk3 Fiesta) had split FL-RR, FR-RL lines coming off the MC. The only driver feature it came with was understeer - no ABS, central locking, leccy windows or power... [smiley=bigcry.gif]
> 
> So... Why do we have to bleed the wheels in a certain order? Is this just unfounded VAG witchcraft...?


Most likely a carryover from the pre ABS era.


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## alexgreyhead (Oct 12, 2015)

David C said:


> Most likely a carryover from the pre ABS era.


Possiblub.

I may do a Googling if I find myself particularly bored one evening... :mrgreen:


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## CapeTownTT (Apr 11, 2013)

Thanks for the info guys! I'll let you know how I get on.


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## Baalthazaar (Jul 11, 2010)

Full brake fluid change at Audi €70.00 ( whatever that is in the old empire paper) problem solved no issue.


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## StuartDB (Feb 10, 2018)

I thought you pressure bleed the brakes starting with the furthered wheel rr,rl,fr,fl then the master cylinder 2 nipples. Don't know why you should cycle the abs pump.


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## alexgreyhead (Oct 12, 2015)

StuartDB said:


> I thought you pressure bleed the brakes starting with the furthered wheel rr,rl,fr,fl then the master cylinder 2 nipples. Don't know why you should cycle the abs pump.


ABS pump needs a specific bleed process if you have (or suspect you may have) air in it.

Audi specify that you should bleed from the caliper closest to the ABS pump.

Nobody seems to have a concrete answer as to why, and my suspicion is it's just Audi making stuff up on purpose to annoy mechanics... [smiley=bigcry.gif]


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## WaynoTTV6 (Apr 9, 2015)

I'd love to have the front brake calipers bled, but I can't, because the last owners have mullered the bleed nipples and rounded them Off!
How the [email protected]@k do you round off a bleed nipple!!!
Think I need to file them down to get a 10mm spanner on. 
Sodding annoying!!

Sent from my SM-G935F using Tapatalk


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## alexgreyhead (Oct 12, 2015)

WaynoTTV6 said:


> bleed nipples ... rounded them Off!


Have you tried an easy-out? You might need to drill the centre of the nipple out to a few mm larger to get a decent size easy-out in there.

You'll also need penetrating oil and possibly heat, I'd imagine.

Once it's out (it'll come out eventually  ), can I recommend fitting some speed bleeders? These things are magic and my newest favourite thing :mrgreen:

/Al


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## WaynoTTV6 (Apr 9, 2015)

alexgreyhead said:


> WaynoTTV6 said:
> 
> 
> > bleed nipples ... rounded them Off!
> ...


Morning Al,

Not tried an easy out. I figured the nipples are hollow so would just collapse with any force applied, including direct heat. Speed replacements will be purchased though. Just need the time to actually tackle it.

Sent from my SM-G935F using Tapatalk


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## Lomondbob72 (May 29, 2018)

I have just replaced all suspension and brake components on all four corners of my 2002 TT (8N). In my ignorance I have inadvertently let the master cylinder run dry so that having now bled all four calipers (using a Sealey pressure unit) the brake pedal presses to the floor. Looks like there is air in the master cylinder. Alex Greyhead has listed the bleeding sequence. Can he or anyone else tell me the best way to get at the two bleed nipples on the master cylinder? Looks like I need to remove a few engine components. Also, and this shows my ignorance. Alex says that the ABS pump has to be bled first. Where is it and what is the VCDS he mentions that is used to bleed the pump. Sorry to sound so stupid.

Bob Sharp


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## David C (Apr 15, 2013)

Lomondbob72 said:


> I have just replaced all suspension and brake components on all four corners of my 2002 TT (8N). In my ignorance I have inadvertently let the master cylinder run dry so that having now bled all four calipers (using a Sealey pressure unit) the brake pedal presses to the floor. Looks like there is air in the master cylinder. Alex Greyhead has listed the bleeding sequence. Can he or anyone else tell me the best way to get at the two bleed nipples on the master cylinder? Looks like I need to remove a few engine components. Also, and this shows my ignorance. Alex says that the ABS pump has to be bled first. Where is it and what is the VCDS he mentions that is used to bleed the pump. Sorry to sound so stupid.
> 
> Bob Sharp


http://www.ross-tech.com/vag-com/


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## Lomondbob72 (May 29, 2018)

Thanks David. I see that the VCDS is windows software. I'm not sure how I would use this to help bleed the ABS so will leave that to my Glasgow Audi dealer. In the meantime I'll have a shot at bleeding the brake master cylinder using the closed loop system. If that doesn't help then I'll have a shot at accessing the reservoir's own bleed nipples. For this I'll need to remove the charge pipe.


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## CapeTownTT (Apr 11, 2013)

Hey bud

You would basically use the bleeding sequence in vcds, which cycles the abs pump, to release the trapped air. Hopefully there's no air in it, and you can just bleed the master. Take care when opening the bleed valves.... I managed to sheer both of mine off. #facepalm

Sent from my HUAWEI VNS-L22 using Tapatalk


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## Pukmeister (Dec 27, 2017)

Alex, do you have a link to those speed bleeder nipples ?

I've sheared a few bleed nipples over the years so when I get around to replacing my TT brake fluid (currently at just under 4% water) I fancy replacing all bleed nipples with shiny new ones and repainting my calipers.

Bleed nipples come in differing sizes hence if you have a link it would save me considerable hassle with removing, blanking and measuring mine.


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## richardkhill (Jul 20, 2015)

Pukmeister said:


> do you have a link to those speed bleeder nipples ?


Ebay example: https://www.ebay.co.uk/itm/Goodridg...ing-Bleed-Nipples-One-Way-Valve-/301071168659

Amazon example: https://www.amazon.co.uk/Goodridge-Speed-Bleeders-10MM-Universal/dp/B000ONZNV4

Neither of those links are for TT specific items, just example sellers.


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## WaynoTTV6 (Apr 9, 2015)

Raising the old thread. I swapped over front bleed nipples yesterday with success. 
Now need to bleed them.
Now, given my system was bled minus the fronts, when I had the fluid changed, can I just bleed the fronts alone, or is it a standard job (4 calipers only)?

I'm an advocate of 2 person bleeding too. So will stick to that method. 8 pumps and last one is held as nipple is done up.

Oh and Merry Christmas.


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## David C (Apr 15, 2013)

WaynoTTV6 said:


> Raising the old thread. I swapped over front bleed nipples yesterday with success.
> Now need to bleed them.
> Now, given my system was bled minus the fronts, when I had the fluid changed, can I just bleed the fronts alone, or is it a standard job (4 calipers only)?
> 
> ...


There are four individual lines from the ABS unit, so providing you didn't loose so much fluid that it (the lack of fluid) went as far back as the ABS, you could just bleed the fronts.

As for bleeding method, I prefer vacuum bleeding. Makes it a very easy one man job.


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## WaynoTTV6 (Apr 9, 2015)

David C said:


> WaynoTTV6 said:
> 
> 
> > Raising the old thread. I swapped over front bleed nipples yesterday with success.
> ...


David, I didn't loose hardly anything. It was straight off with old and straight on with the new.


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