Brake Fluid Flush B5.5

HazenVagen

Active member
Joined
Mar 20, 2005
Location
Washington, USA
TDI
Passat Wagon, 2005, United Gray
Well, its officially Spring, and my 2005 GLS Passat TDI is only ten days past her 2nd birthday (46k mi.), so it's time for a brake system flush. I've done the obligatory forums search and found that our Jetta brethren (and sistern? I crack myself up!) are the only ones that have posted on this subject at any substantive length. Their thread on the flush DYI leaves me with some unanswered questions that may be specific to our B5's, so I post here.
I've flushed several systems, including but not limited to, my wife's MkIII Jetta, my daughter's 2001 Subbie, and my old '91 300TE 4Matic Benzo. I use a SpeediBleeder. All of these rigs were equipped with ABS and it is my understanding that in order to properly flush an ABS equipped brake system one must use 32 PSI at the master cylinder; which I've done successfully with the aforementioned beasties.
The A4 flush thread makes mention of NOT using more than 14 PSI (though DieselDorf mentions using 18 PSI with no ill effects). What's up with that? My MB Service Library specifically notes the higher working pressure. Can the systems be THAT different?
Also, there seems to be some difference of opinion on the order of caliper bleed. I've always used RR, LR, RF, LF as a method, though the A4 thread mentions the exact opposite is to be used on newer ABS equipped models. Yikes! I feel a bit like Rip VanWinkle or Alice through the looking glass. Did my nap take a bit longer than I reckoned? Did I fall down a rabbit hole?
Can someone explain what it is I've missed? Thank you in advance for your patient understanding.
Best regards,
HazenVagen
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
On the A4s, VW states exceeding 14 PSI (1 bar) will cause the proportioning valve inside the ABS unit to prevent a proper flushing.

A4 systems equipped with MK 60 controllers user LF, RF, LR, RR sequence. The arrangement of the pipes connecting to the controller is the reason. This sequence gets the most air (if any) out of the system first.

However, you don't have the A4 platform vehicle.

The 2004-2005 TDI Passats are different. The procedure does specify to use a pressure of at least 2 bar. Sequence is RR, LR, RF, LF.
After a normal bleed, the procedure states that a second person is needed. Then...

Depress brake pedal forcefully and hold.
Open bleeder valve on brake caliper.
Press brake pedal down onto stop.
Close bleeder valve with pedal held down.
Release brake pedal slowly.

This bleeding sequence must be performed 5 times per brake caliper.
Bleeding sequence:
Right rear brake caliper
Left rear brake caliper
Right front brake caliper
Left front brake caliper

Vehicles with ABS, ABS/EDL, ABS/EDL with ASR or ABS/EDL with ASR and ESP.
A test drive must be performed for these vehicles after bleeding the brakes. During this, at least one ABS regulation must be performed!
 

HazenVagen

Active member
Joined
Mar 20, 2005
Location
Washington, USA
TDI
Passat Wagon, 2005, United Gray
Thank you, MoGolf!
Well, I did the first sequence correctly, but I did not do the second sequence.:eek: I'll do it tomorrow when I have a helper.
Whilst sitting in driveway at idle, I depressed the brake pedal and with force the pedal went to the floor a few times. I also pumped the hand brake a few times. I was a bit concerned at the way the pedal went to the floor (maybe not all the way to the stop). I cautiously backed out of my drive way and tested the brakes, The pedal got hard and the wagon quickly stopped.
I then went around the neighborhood at maybe 25 MPH and did a few stops. The pedal travelled normally (a bit less than it had been prior to the flush) and the car braked evenly and quickly. The pedal felt noticeably harder than it did yesterday.
After building some confidence I took it out for a real drive. The brakes worked flawlessly. It's raining here so I did two full panic stops from 40 and 50 MPH. Again, the brakes and ABS worked like champs with quick straight stops.
BTW that little screen filter in the top of the brake fluid reservoir is a booger to remove. I assume it's not meant to be re-used as I couldn't figure a way to get it out without damaging the POS.
Thanks again for the info, MO.
Best regards,
HazenVagen
P.S. My variant is ABS,ASR and ESP equipped.
 

engineerorange

Veteran Member
Joined
Jan 6, 2005
Location
North Carolina
TDI
2015 Jetta
Fluid amount

Getting ready to do the flush on the passat. Thanks Mogolf for the procedure. How many liters of fluid does it take to do a complete change on a B5.5?
 

tomsawyer

Well-known member
Joined
Dec 28, 2005
Location
Totowa, NJ
TDI
2005 Passat TDI
Guys - My 05 Passat is coming up on 2 yrs & I guess its time to change flush the brake fluid.

Do most of you do it yourselves or do you take it to the dealer?

I changed the oil & fuel filter already with no problem but I am not so sure how to flush the brake fluid.

If I take it to the dealer to do the flush, what things should I be aware of and how do I make sure they do it right?

Thanks.
 

jrock

Veteran Member
Joined
May 3, 2004
Location
Dallas, TX
TDI
Jetta, 2001, Blue, Passat, 2012 Silver
MOGolf,

Said it about best, you could see if your dealer follows this procedure.

Jesse
 

owr084

Top Post Dawg
Joined
Oct 20, 2004
Location
Northern Virginia (NoVA)
TDI
Passat GLS, 2005, Stonehenge Gray
What do those steps do that isn't done if you flush the system with a motiv brake bleeder? I'm confused. Why after power flushing the system and not letting air or anything other than fresh fluid into the system would you need to do the pump the brake pedal and bleed routine?

MOGolf said:
After a normal bleed, the procedure states that a second person is needed. Then...

Depress brake pedal forcefully and hold.
Open bleeder valve on brake caliper.
Press brake pedal down onto stop.
Close bleeder valve with pedal held down.
Release brake pedal slowly.

This bleeding sequence must be performed 5 times per brake caliper.
Bleeding sequence:
Right rear brake caliper
Left rear brake caliper
Right front brake caliper
Left front brake caliper

Vehicles with ABS, ABS/EDL, ABS/EDL with ASR or ABS/EDL with ASR and ESP.
A test drive must be performed for these vehicles after bleeding the brakes. During this, at least one ABS regulation must be performed!
 

HazenVagen

Active member
Joined
Mar 20, 2005
Location
Washington, USA
TDI
Passat Wagon, 2005, United Gray
The second procedure that MoGolf mentions sounds redundant to me, too. When I asked the dealer service manager about it he looked puzzled and he went out to the service floor and talked to a tech. He came back and said "Never heard of it."
Who knows?
Before taking it to you dealer ask the service manager what procedure they use. If you don't get a warm fuzzy find an independent.
Don't do it yourself if you don't have a power bleeder.
 

06JettaTDIdsg

Veteran Member
Joined
Aug 19, 2005
Location
Parker, CO
TDI
2006 Jetta TDI DSG
Bringing this back to the top. I am going to use my Motive Products power bleeder to flush the fluid. What is the proper pressure to apply? 2 bar = 44.1psi. Am I correct on this figure?

Additionally, what type of fluid is needed? DOT 4?
 

MOGolf

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Joined
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Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
owr084 said:
What do those steps do that isn't done if you flush the system with a motiv brake bleeder? I'm confused. Why after power flushing the system and not letting air or anything other than fresh fluid into the system would you need to do the pump the brake pedal and bleed routine?
It is the procedure prescribed by VW with no explanation given. They use a pressure bleeder too.

You're just looking to be sure the fluid comes out free of air bubbles during that brake pedal process.
 

diesel#2

Veteran Member
Joined
Oct 3, 2000
Location
Baltimore, MD, USA
TDI
2014 Jetta Sportwagen, 2004.5 Passat Variant (sold), 2000 Golf (still in family), 1998 jetta (RIP)
amount of brake fluid for flush?

this was asked all ready-- but I don't see a response (and can't find it in the owners manual or on the forum)... quick response folks?

engineerorange said:
Getting ready to do the flush on the passat. Thanks Mogolf for the procedure. How many liters of fluid does it take to do a complete change on a B5.5?
 

MOGolf

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Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
For a thorough flush, I get two quarts of DOT 4 brake fluid (local part store does not sell by the liter), and get 400-500 ml per caliper through.
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Leave it in place.
 

plowboy_lurch

Active member
Joined
Sep 6, 2005
TDI
2005 Passat , 2013 Passat SEL
Mogolf, I am replacing my master cylinder in my B5.5 and will do the procedure you recommend. I have to ask though, on the assisted bleed, do I need to make 5-trips aroung the vehicle bleeding each cylinder once or one trip bleeding each cylinder 5 times? And if I have to bleed the ABS pump what is the procedure for that?
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
I've done several brake bleeds since posting that procedure way back then.
I have yet to figure out why VW says that. It seems like standard brake bleeding procedures is good enough.

What I do for a MC replacement, after installing it, is disconnect the lines from MC to ABS at the ABS. Cap holes to keep out dirt and air. Attach tubing to the lines and run them back to the MC reservoir. Pump the brake slowly to clear the MC of air. Keep the reservoir full.

Once that is done, quickly remove tubing from a line and connect it to the ABS. Repeat for the other. This keeps air out of the system. Have plenty of clean towels/rags round the area to absorb spilled fluid.

Then bleed the brake system at each wheel the normal way. Running at least 1/2 liter through each brake ensures good fluid throughout and no air.
 
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