# DIY:Brake Flush MK4



## Steveo989 (Jan 21, 2006)

Quick and to the point, the reason to change your brake fluid is to save your ass! Brake fluid is a hydroscopic which means it attracts water, big deal right? Wrong, through the brake lines and through your resevoir brake fluid attracts water, water has a really low boiling point, the more water in your lines the lower your boiling point. So you smash the brake pedal to stop you from slaming into the car ahead of you but your brakes barely keep you from hitting him. Your pedal feel may be very "mushy" as some may say. Your pads and rotors are fine so what's the deal. When you slammed your brakes their is a good chance your brake fluid boiled, in turn becoming a gas. Which we all know you can compress gas a lot! So your pedal sinks to the floor. 
Of course that is worst case scenerio but that is the situation that we are trying to avoid by changing our fluid.
Another reason is with our expensive ABS ESP etc. etc. we want to prolong their life as long as we possibly can, new brake fluid will keep corrosion to an absolute minimum. http://****************.com/smile/emthup.gif 
*Bentley Recommends changing your fluid every two years regardless of mileage. Which is a pretty safe bet, however those of us that drive our asses off may want a bit more insurance, my recommendation is every 30,000 miles or 1 1/2 years. Whichever comes first. Mainly for the fact that in 2 years the fluid has already taken on too much water and is already doing too much damage.*

Tools Required: Jack Jackstands, 11mm open ended wrench(9mm wrench for 6spd slave cylinder bleed) Motive power bleeder or equivalent, catch bottles or tubing to collect old fluid, turkey baster to remove old fluid from resevior.
Start with the simple part:
1.Begin loosening up your lugs on your wheels. 
2.Jack up your vehicle and support it with jackstands. 
3. Remove your wheels. This will let you have plenty of room to work and the front calipers it is nearly impossible to bleed without removing the wheels.
4.Due to variances in 1.8t, tdi, 2.0l, VR6, 3.2l. Remove whatever you need to to have good access to the front of the the brake fluid resevoir.
5. Now remove the yellow fluid level sensor from the brake fluid resevoir.
6. Next take out the plastic screen insert inside the resvoir with a flat head screwdriver as pictured.








7.Take the time to remove any obvious dirt from the plastic screen or the sensor.
8. Begin removing the old fluid from the resevoir as pictured.








9.With a very clean paper towl or other item remove obvious dirt from inside the resevoir. 
10. Fill the resevoir with whatever your choice of fluid is, my friend's choice was ATE SUPER BLUE.








11. Now with an EMPTY Power Bleeder test the seal on the resevoir. This will save you the nightmare if their was an insufficent seal on the resevoir.








12.Now you can fill your power bleeder with the remainder of whatever fluid you have choosen.








13. Pressurize the system to 10-13psi. The older the resevoir the less pressure you want to use. This keeps the resevoir from rupturing.(You really only need to worry about this on old resevoirs I would say 8 years old+
14.Now we begin the fun part of flushing your lines, bleed the clutch first, (5spdMK4 you simply bleed untill you get all new fluid.11mm wrench) (6spd bleed off about 100cc's of fluid, close the bleeder screw,quickly pump the clutch pedal 15 times, then bleed 50cc's of fluid.If I remember correctley this is a 9mm wrench)
15. Anyway crack open the bleed screw for the clutch and bleed as what is said above.
5spd
















16. Close your bleed screw, and don't touch the clutch untill the rest of the system is flushed. This will keep old fluid from potentially mixing with the new fluid.
17. Now open the bleed screw on the right rear caliper. When only new fluid comes out. Their should be no air or corrosion coming out of the line when you close the bleed screw.








































18.Repeat on the rear left(driver rear)

19. Repeat on the front right(passenger front) 
































20.Repeat on front left front(driver front)
21. Repeat as necessary I would hit all the brakes twice to get all the old fluid out for sure.
22. Now do the opposite of removing everything and deperessurize the pump.
23. Finally Have a beer







and cycle your abs pump, not in that order either









_Modified by Steveo989 at 9:32 AM 4-15-2007_

_Modified by Steveo989 at 9:37 AM 4-15-2007_

_Modified by Steveo989 at 9:51 AM 4-15-2007_

_Modified by Steveo989 at 9:56 AM 4-15-2007_


_Modified by Steveo989 at 9:51 PM 4-20-2007_


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## Steveo989 (Jan 21, 2006)

Time for a plug


















_Modified by Steveo989 at 9:58 AM 4-15-2007_


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## Steveo989 (Jan 21, 2006)

Any ?'s, comments concerns feel free to post or pm me. I will make corrections or make things a bit more user friendly.


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## Tim_1.8T (Jan 20, 2006)

*Re: (Steveo989)*

Excellent DIY! 
I have one question though, how do you cycle the ABS pump?


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## Steveo989 (Jan 21, 2006)

You know when you brake you feel the brake pedal pulsate, that's what I am talking about. On a dry road you need to smash the pedal to activate it.


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## screwedrrado (Mar 13, 2007)

*Re: (Steveo989)*

Steve,
I have read up on the rear disk calipers on VW's and have noticed that the rears don't bleed well if you have air in the system, supposedly when the caliper sits in its normal position, one of the corners can hold an air pocket, what I have seen is that you take off the caliper from the carrier and tilt it till the bleeder is point to the sky, therefore any air bubbles will rise and all air is removed. I have not done this, therefore I am unsure if its true, but I have paid attention the the design and it can happen. Thanks for the DIY, defintely needed


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## the_q_jet (Mar 19, 2005)

well documented and well done!


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## huskylord (Nov 20, 2005)

*Re: (the_q_jet)*

pardon this noob, but when you mention bleed the clutch, do you actually mean the clutch used for shifting gears? 
once again, go easy on the noob....


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## Steveo989 (Jan 21, 2006)

Bleed the clutch's slave cylinder, bleed the clutch i guess is slang for it.


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## newcreation (Nov 23, 2003)

*Re: (Steveo989)*

nice needed this


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## huskylord (Nov 20, 2005)

With the pressure bleeder, you don't need to press the brake pedal at all, right?
Second part, with the Motive Bleeder I see you're using, can this work on my 97 Jetta and an Acura Integra? (my dad's car....I could then justify spending the kind of cash it probably would cost)


_Modified by huskylord at 2:46 PM 4-20-2007_


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## Steveo989 (Jan 21, 2006)

*Re: DIY:Brake Flush MK4 (Steveo989)*

probably not the integra but the jetta yes, and you only need to tap the brake pedal if you are having trouble bleeding, this will activate the circuit if you will.


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## blkpain1.8t (Aug 21, 2006)

*Re: DIY:Brake Flush MK4 (Steveo989)*

GREAT write up! Thanks! http://****************.com/smile/emthup.gif 


_Modified by JLS6011 at 12:01 PM 5-10-2007_


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## blkpain1.8t (Aug 21, 2006)

*Re: DIY:Brake Flush MK4 (Steveo989)*

Okay, so I followed your instructions step by step to the letter. Then I changed the pads and rotors on all 4 corners. Aside from various (some unrelated) snags it went okay. 
However, my problem is that now I cannot get the ABS to cycle. What I mean is, I drove the car after I buttoned everything up and did a few low speed stops to ensure the brakes work (which they do) then I got it up to about 40-45mph and stomped on the brakes to get the ABS to cycle. Unfortunately, no ABS. Instead I have soft brakes. The pedal is solid but the braking is softer than it should be. So, I thought maybe I had air in the system. I bled the brakes and gave it another go. Same result. Braking was improved this time but still no ABS. The brakes just aren't grabbing hard enough to lock up hense the ABS is not engaging. 
After yet another bleed, the brakes are slightly more improved but still not good enough to engage the ABS.
Here's what I was thinking may be the problem(s):
-Air still trapped in the system
-Air trapped in the master cylinder
-ABS sensor is not working
-Pads and rotors just need time to seat in before they will perform optimally. 
Now, after a full system flush and 3 different bleeds I find it unlikely that there's still air in the system. It's not impossible, but unlikely. I am pretty confident that it's not air related because the pedal is solid and I don't get any pedal fade, pulsing or anything like that. I get a hair more travel in the pedal than before, but it's very minute. 
There is a possibility that air got into the master cylinder, especially since it was emptied with a turkey baster prior to being refilled with new fluid. If this is the case, I don't know how to bleed the MC on OR off the car.















What is the likelyhood that the new pads and rotors are infact just needing some mileage to "break in" and get seated properly? I got that opinion from a very trustworthy person, but I wanted to get some other trustworthy opinions. 
The car is certainly driveable, but I am concerned about having no ABS and the brakes being slightly softer than normal. 
Help?


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## a4tq (Jan 18, 2004)

*Re: DIY:Brake Flush MK4 (JLS6011)*

I have a similar issue with my R32. I've got a thread going over in the R32 forum, and one suggestion was to cycle the abs pump with a vagcom.
I've made an appointment with the dealership to see if they can bleed it better than I can, and will let you know the result.
Have you gone thru a bed in procedure with the pads/rotors?


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## rastta (Feb 22, 1999)

*Re: DIY:Brake Flush MK4 (JLS6011)*


_Quote, originally posted by *JLS6011* »_Okay, so I followed your instructions step by step to the letter. Then I changed the pads and rotors on all 4 corners. Aside from various (some unrelated) snags it went okay. 
However, my problem is that now I cannot get the ABS to cycle. What I mean is, I drove the car after I buttoned everything up and did a few low speed stops to ensure the brakes work (which they do) then I got it up to about 40-45mph and stomped on the brakes to get the ABS to cycle. Unfortunately, no ABS. Instead I have soft brakes. The pedal is solid but the braking is softer than it should be. So, I thought maybe I had air in the system. I bled the brakes and gave it another go. Same result. Braking was improved this time but still no ABS. The brakes just aren't grabbing hard enough to lock up hense the ABS is not engaging. 
After yet another bleed, the brakes are slightly more improved but still not good enough to engage the ABS.
Here's what I was thinking may be the problem(s):
-Air still trapped in the system
-Air trapped in the master cylinder
-ABS sensor is not working
-Pads and rotors just need time to seat in before they will perform optimally. 
Now, after a full system flush and 3 different bleeds I find it unlikely that there's still air in the system. It's not impossible, but unlikely. I am pretty confident that it's not air related because the pedal is solid and I don't get any pedal fade, pulsing or anything like that. I get a hair more travel in the pedal than before, but it's very minute. 
There is a possibility that air got into the master cylinder, especially since it was emptied with a turkey baster prior to being refilled with new fluid. If this is the case, I don't know how to bleed the MC on OR off the car.















What is the likelyhood that the new pads and rotors are infact just needing some mileage to "break in" and get seated properly? I got that opinion from a very trustworthy person, but I wanted to get some other trustworthy opinions. 
The car is certainly driveable, but I am concerned about having no ABS and the brakes being slightly softer than normal. 
Help?









This sounds like you haven't properly bedded in the pads properly. Are these different from the pads you had in originally? Were your original OEM? 
It doesn't sound like a bleeding issue - but more like a pad issue to me.


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## blkpain1.8t (Aug 21, 2006)

*Re: DIY:Brake Flush MK4 ([email protected])*

Yeah, I went with all new pads and rotors on all 4 corners. Bendix OEM replacements in the front and Duramax in the rears (I know I know...but I am poor







) I know some pads are better than others but beyond a certain point pads are pads are pads right? 
Anyway, the brakes are improving little by little each day, and the dealer checked the ABS today which is "sending the signal" just fine - whatever that means.








Aside from what I am currently doing which is just driving the car carefully to help break in the new parts is there any other/better ways to propperly bed in the pads?
I am leary about mashing the pedal too many more times to test the ABS/bed the pads. I guess there's only one way to find out though right








BTW - to the OP...sorry for the thread jack. Mods feel free to do as you do if you feel the need to do it


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## blkpain1.8t (Aug 21, 2006)

*Re: DIY:Brake Flush MK4 (a4tq)*

What is this "bed procedure" I have been hearing about? What exactly do I need to do to properly bed them?


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## rastta (Feb 22, 1999)

*Re: DIY:Brake Flush MK4 (JLS6011)*

Bedding in the brakes is doing about 6-8 repeated stops from 60-80mph to about 5mph. This allows the pads to bed in with the rotors. If you don't do this - you run the risk of glazing the pads and reducing brake effectiveness.


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## spitpilot (Feb 14, 2000)

*Re: DIY:Brake Flush MK4 ([email protected])*

Wow..very professional DIY! I've never had the catch bottle and all that, just dumped fluid into an old dog dish







...another way to do the job if you don't have the pressure bleeder is to use a "mighty vac" to apply vaccum to each bleed port and draw new fluid thru the system...guess the choice is whether you prefer...blow..or suck!


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## Steveo989 (Jan 21, 2006)

Thanks^^^


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## nfj-bronfufu (Jan 12, 2006)

do i have to bleed the clutch first? and is there anyway to get a cheaper power bleeder locally?


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## MitchD1283 (May 24, 2006)

*Re: (nfj-bronfufu)*

excellent instructions. i do have one concern about your procedure, i noticed that you said to remove the screen from the reservoir; i recommend NOT doing this. I work for VW at a dealer and I know that by removing that screen that it is a possibility that small pieces of that screen can break off and plug up a line and or contaminate the abs pump. I have known this to happen so I recommend just leaving it in and bleeding the brakes a little longer to flush out the old fluid.


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## Steveo989 (Jan 21, 2006)

*Re: DIY:Brake Flush MK4 (Steveo989)*

ttt


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## O2VW1.8T (Jul 9, 2003)

*Re: (MitchD1283)*


_Quote, originally posted by *MitchD1283* »_excellent instructions. i do have one concern about your procedure, i noticed that you said to remove the screen from the reservoir; i recommend NOT doing this. I work for VW at a dealer and I know that by removing that screen that it is a possibility that small pieces of that screen can break off and plug up a line and or contaminate the abs pump. I have known this to happen so I recommend just leaving it in and bleeding the brakes a little longer to flush out the old fluid.

i worked at VW dealer to and ever tech removed it and sprayed it down with brake kleen cause it gets lots of black build up crap.. If you use the wrong tools it will break. Dont be crazy when you pull it out


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## simplyredvw (Mar 20, 2001)

*Re: DIY:Brake Flush MK4 (Steveo989)*

Nice DIY post.
I did want to mention that I wouldn't be too worried about the pressure in the self-bleeder. I've regularly flushed my 20AE with a electric power bleeder from Germany that runs at 2 bar (29.4 psi) and have had no problems. I also flush a lot of European cars with a manual bleeder with at least 20 psi and have never had a problem. 
BTW, some sports car manufacturers recommend a 1 year brake fluid change interval.


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## Steveo989 (Jan 21, 2006)

*Re: DIY:Brake Flush MK4 (simplyredvw)*


_Quote, originally posted by *simplyredvw* »_Nice DIY post.
I did want to mention that I wouldn't be too worried about the pressure in the self-bleeder. I've regularly flushed my 20AE with a electric power bleeder from Germany that runs at 2 bar (29.4 psi) and have had no problems. I also flush a lot of European cars with a manual bleeder with at least 20 psi and have never had a problem. 
BTW, some sports car manufacturers recommend a 1 year brake fluid change interval.








Personally I am sticking to 9 months.


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## CrymynylMynd (Oct 19, 2008)

*Re: DIY:Brake Flush MK4 (Steveo989)*

Nice work, this will really come in handy tomorrow. I'd just like to say, I was having a look at the procedure in the VW Golf/Jetta Bentley's Service Manual (which I think everyone should have a copy of) and it says:
WARNING!
Do not exceed a filling pressure of 1 bar (14.5
psi) when filling with brake fluid using brake
filler and bleeder unit VAS 5234. The brake
system will not be completely bled if
excessive pressure is used.
And then after the usual stuff about how poisonous brake fluid is and how you should keep it off paintwork blah blah it says:
Do not use silicone-based brake fluid (DOT 5).
Even the smallest trace can cause severe
corrosion in the brake system.
Just thought people should know what they recommend because the Eezibleed instructions says to use up to 20PSI.
Again, thanks for the howto.
Crym


_Modified by CrymynylMynd at 4:06 PM 11-1-2008_


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## spitpilot (Feb 14, 2000)

*Re: DIY:Brake Flush MK4 (Steveo989)*


_Quote, originally posted by *Steveo989* »_Quick and to the point, the reason to change your brake fluid is to save your ass! Brake fluid is a hydroscopic which means it attracts water, big deal right? Wrong, through the brake lines and through your resevoir brake fluid attracts water, water has a really low boiling point, the more water in your lines the lower your boiling point. So you smash the brake pedal to stop you from slaming into the car ahead of you but your brakes barely keep you from hitting him. Your pedal feel may be very "mushy" as some may say. Your pads and rotors are fine so what's the deal. When you slammed your brakes their is a good chance your brake fluid boiled, in turn becoming a gas. Which we all know you can compress gas a lot! So your pedal sinks to the floor. 
Of course that is worst case scenerio but that is the situation that we are trying to avoid by changing our fluid.
Another reason is with our expensive ABS ESP etc. etc. we want to prolong their life as long as we possibly can, new brake fluid will keep corrosion to an absolute minimum. http://****************.com/smile/emthup.gif 
*Bentley Recommends changing your fluid every two years regardless of mileage. Which is a pretty safe bet, however those of us that drive our asses off may want a bit more insurance, my recommendation is every 30,000 miles or 1 1/2 years. Whichever comes first. Mainly for the fact that in 2 years the fluid has already taken on too much water and is already doing too much damage.*

Tools Required: Jack Jackstands, 11mm open ended wrench(9mm wrench for 6spd slave cylinder bleed) Motive power bleeder or equivalent, catch bottles or tubing to collect old fluid, turkey baster to remove old fluid from resevior.
Start with the simple part:
1.Begin loosening up your lugs on your wheels. 
2.Jack up your vehicle and support it with jackstands. 
3. Remove your wheels. This will let you have plenty of room to work and the front calipers it is nearly impossible to bleed without removing the wheels.
4.Due to variances in 1.8t, tdi, 2.0l, VR6, 3.2l. Remove whatever you need to to have good access to the front of the the brake fluid resevoir.
5. Now remove the yellow fluid level sensor from the brake fluid resevoir.
6. Next take out the plastic screen insert inside the resvoir with a flat head screwdriver as pictured.








7.Take the time to remove any obvious dirt from the plastic screen or the sensor.
8. Begin removing the old fluid from the resevoir as pictured.








9.With a very clean paper towl or other item remove obvious dirt from inside the resevoir. 
10. Fill the resevoir with whatever your choice of fluid is, my friend's choice was ATE SUPER BLUE.








11. Now with an EMPTY Power Bleeder test the seal on the resevoir. This will save you the nightmare if their was an insufficent seal on the resevoir.








12.Now you can fill your power bleeder with the remainder of whatever fluid you have choosen.








13. Pressurize the system to 10-13psi. The older the resevoir the less pressure you want to use. This keeps the resevoir from rupturing.(You really only need to worry about this on old resevoirs I would say 8 years old+
14.Now we begin the fun part of flushing your lines, bleed the clutch first, (5spdMK4 you simply bleed untill you get all new fluid.11mm wrench) (6spd bleed off about 100cc's of fluid, close the bleeder screw,quickly pump the clutch pedal 15 times, then bleed 50cc's of fluid.If I remember correctley this is a 9mm wrench)
15. Anyway crack open the bleed screw for the clutch and bleed as what is said above.
5spd
















16. Close your bleed screw, and don't touch the clutch untill the rest of the system is flushed. This will keep old fluid from potentially mixing with the new fluid.
17. Now open the bleed screw on the right rear caliper. When only new fluid comes out. Their should be no air or corrosion coming out of the line when you close the bleed screw.








































18.Repeat on the rear left(driver rear)

19. Repeat on the front right(passenger front) 
































20.Repeat on front left front(driver front)
21. Repeat as necessary I would hit all the brakes twice to get all the old fluid out for sure.
22. Now do the opposite of removing everything and deperessurize the pump.
23. Finally Have a beer







and cycle your abs pump, not in that order either









_Modified by Steveo989 at 9:32 AM 4-15-2007_

_Modified by Steveo989 at 9:37 AM 4-15-2007_

_Modified by Steveo989 at 9:51 AM 4-15-2007_

_Modified by Steveo989 at 9:56 AM 4-15-2007_

_Modified by Steveo989 at 9:51 PM 4-20-2007_

Damn nicely put info! Good DIY! Only caution I'd lay out there is that the MKV (in case some MKV owners read this or some MKIV guys wanna help out their buddies who run MKV's) MKV bleeding sequence isn't like older VW's (RR, LR, RF, LF) it goes LF, RF, LR, RR..don't ask me why but its in the Bible..errrr..Bentley for MKV. Also, after pressure bleed, Bentley reccomends doin 5 pump bleeds for each wheel as final step..guess movin the caliper pistons around like you do with pump bleeding helps to get last bit of old fluid/air outa there. Another approach for those who don't wanna spring for $50 power bleeder...or have it hangin around the garage for 1 1/2 to 2 years waiting for next bleed cycle...do vaccum bleed. You can do this with an attachement to a vaccum tester (just a catch tank for the fluid you hook up between the tester and the bleeder screw) or if you don't have a vaccum tester...go to medical supply store and ask for a "cathater flush syringe"..its a nylon syringe body with a tapered snout and a capacity of 60cc...you hook up a length of 3/16" PVC clear tubing to this puppy and it will suck that old fluid right outa there. Small and cheap! http://****************.com/smile/emthup.gif


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## dallas04gli (Jun 25, 2007)

awsome diy. bookmarked


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## jlsgli89-03 (Aug 25, 2003)

i was reading my bentley,and when it came to the bleeding section,it asks if my car has ITT MARK 60 IE SYSTEM.then it recomends doing a zero compensation of the brake pressure sender with a scan tool.and follow a proceedure before bleeding.has anyone ever done this and is it really neccessary to do.


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## Veedubboy75 (Feb 13, 2004)

*Re: (jlsgli89-03)*

i'm a n00b and i'm in school right now for auto, and we're doing brakes.
so i figured, "hey look up brake bleeding for vws................"
the only thing i'd change about this diy is, circling the parts (screws, etc) with red in photoshop, i didn't really know what parts you were referring to in your pictures when talking about the clutch pictures :/

thanks for doing this though, great job.
n00b


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## fastgascar (Jul 30, 2001)

*Re: DIY:Brake Flush MK4 (Steveo989)*

I didn't want to bring this one back from the dead, but I am working on an MKiV and I am using a power bleeder. Everything is sealed when I open up the clutch cylinder bleed screw there is no fluid that comes out. Why is this? Any suggestions on how to fix this. The pedal just drops to the floor.


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## jblank4 (Jul 21, 2011)

how many liters will you need? or to buy?


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## bert06040 (Feb 10, 2011)

*Fluid Question*

I have an '05 Passat. Today a buddy and I changed all the rotors and pads on it. He emptied out what he could from the reservior with a turkey baster. When he refilled it, he inadvertently poured DOT 3 into the reservior. I immediately pointed out that the res. stated only DOT 4. He then syphoned it out with the baster and refilled it with the appropriate fluid type, DOT 4. My question/concern is will this cause any damage to the break system? And should I flush the system completely? Or will it be ok as is? Thanks.


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## uNclear (Aug 30, 2011)

^^ one liter is enough!


^ flush it well (as you should anyay), it'll be fine!


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## austinhealey (Mar 10, 2010)

*not a fan of the pressure bleeder for an MK4*

Bumping the old but useful thread... I have never had any luck with a power bleeder (Motive, in my case) doing MK4 brakes -- they always turn out as soft or softer as they were before the bleed. My theory is that air and/or old fluid doesn't completely flush from the lines using a power bleeder (I used mine at the recommended 14.5 PSI). I did mine twice (05 Euro-spec Golf Wagon w/ the Mark 60 ABS system) with the Motive, once normally and once removing the bleeder, pumping the brakes 10 times, then bleeding each corner again (pumping between corners). The second time was better but still not as firm as they should be. I pushed 1.5 L of fluid through the system during those two pressure bleeds.

Then I did the old school way, having a friend pump them 5 times and hold. I saw much more air and old fluid come out even after the two bleeds with the pressure bleeder. It was like a new car, I could lock up the brakes by just angling my ankle now and applying pressure rather than mashing down on the pedal with my entire leg. 

Also, cleaning the pressure bleeder after and making sure it doesn't go empty is a bigger hassle than just making sure the master cylinder doesn't go empty and adding fluid. I also did the old school method starting from the furthest corner from the master cylinder and working my way closer, despite Bentley's recommendation of LF RF LR RR for the MK 60 system. And I didn't mess with any VCDS ABS bleed or anything (which as I understand it you only need to do if you accidentally empty the master cylinder).

I was reading a lot of reports of people having soft brakes on an MK4 here and elsewhere and a common theme was the pressure bleeder. The pressure bleeder does work well on my old Land Rover 110, but then that's a much simpler system without ABS.

Hope this helps someone down the road.


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## clarkma5 (Mar 2, 2002)

I have the motive bleeder and have gotten it down to the point where I've had great pedal feel doing bleeds by myself. It takes care and an understanding of the ABS system.

For a start, it takes several cycles of applying pressure with the hand pump and releasing it (by unscrewing the cap at the bleeder reservoir, just enough for the pressure to do its thing, no need to remove it completely) when you first attach the cap to the master cylinder reservoir in order to get every last bubble of air out of the master cylinder reservoir and the motive bleeder hose. Once that's done, I pressurize the bleeder and then use the VAGCOM to cycle the ABS pump (I know people say it's not necessary, but I only got good results once I did this), using the instructions on the VAGCOM to apply and release brake pedal pressure when it says, open and close bleeder screws when it says, and so on. Also, check which ABS system you have: older Mk4s use the conventional bleeding order of RR, LR, RF, LF, clutch. Newer ones do the fronts before the rears, so: RF, LF, RR, LR, clutch. After cycling the ABS module with the VAGCOM a few times, keep the system pressurized and do the appropriate order of opening and closing bleeder screws several times and move a significant amount of fluid through everything. Cycling the parking brake while you're bleeding the rears released a large amount of air bubbles last time I did it (granted, this was because I had pulled the rear calipers apart and they were dry), and you should always give the caliper some taps with a wrench or something to knock any bubbles loose while you're bleeding them. Lastly, be sure to push enough fluid through the system that you're allowing any bubble that may have originated at the ABS pump to come out of the farthest bleeder screw. That can take a pretty large amount of time/fluid because the flow rates in those little brake lines under ~8 psi is not very fast. Be patient, err on the side of pushing more fluid than less, and you should be good to go. Via trial and error I've arrived at this method, and it resulted in the firmest pedal I've ever had, and that includes when the car was new from the factory and after dealer-performed brake fluid changes.


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## vroomstick (Feb 19, 2013)

So I have to change the clutch fluid every time I change the brake fluid? I thought clutch fluid (isn't this also called gear oil) never had to be changed. 

-Guilty noob


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## clarkma5 (Mar 2, 2002)

vroomstick said:


> So I have to change the clutch fluid every time I change the brake fluid? I thought clutch fluid (isn't this also called gear oil) never had to be changed.
> 
> -Guilty noob


The clutch and brake systems are one and the same, hydraulically. They both operate on the brake fluid that is contained in the lines and master cylinder reservoir. So when you do a brake bleed, you have to bleed the clutch as well; when you do a clutch bleed, you have to bleed the brakes as well. It is one system.


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## vroomstick (Feb 19, 2013)

Damn. Can I buy fluid at AutoZone or do I have to go to VW for the brake and clutch fluid?


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## clarkma5 (Mar 2, 2002)

vroomstick said:


> Damn. Can I buy fluid at AutoZone or do I have to go to VW for the brake and clutch fluid?


For Mk4s, you want DOT4 or DOT5.1 brake fluid, available anywhere. Don't get DOT3 or DOT5, they are the wrong types and will cause major corrosion of your braking components.


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