changing brake and clutch unit fluids

Is this a DIY job? I've bled brake systems on my motorcycles in the past, but never in a car....any DIY picture tutorials from members here?

Absolutely a DIY! A power bleeder is relatively cheap and makes this job sooo much easier. Keep in mind the first fluid flush your '15 will need is three years after manufacture date which for me is technically this year with a late '14 production date.
In a nutshell: fill the bleeder with 1 liter of fluid, hook up to reservoir and pressurize to 29psi (yes, 29psi is what the erWin manual states for brakes and clutch on the '15), open one bleed screw at a time in the order of FL FR RL RR and then clutch. When you get to the clutch you have to pump the pedal manually as fast as you can 10 times.

adjat84th said:

...open one bleed screw at a time in the order of FL FR RL RR...

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So when did VW change the sequence? It has always been Right Rear, Left Rear, Right Front, Left Front - farthest to nearest caliper to the master cylinder.

^that would be correct

That's the sequence posted in erWin

The bleeding of hydraulic system using the Brake Charger/ Bleeder Unit - VAS5234- is described.
A positive pressure of 2 bar (29 psi) required to bleed the ABS Hydraulic Unit - N55- .

– Remove the rear wheels on vehicles with 15" rims.
Adhere strictly to work sequence when bleeding brake system.
– Connect the Brake Charger/Bleeder Unit - VAS5234–
Open the bleeder valves in the specified sequence and bleed the brake calipers.
1- Front left brake caliper
2 - Right front brake caliper
3 - Left rear brake caliper
4 - Right rear brake caliper

1854sailor said:

So when did VW change the sequence?

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2 or 3 generations ago. I think the intent is to avoid sending old fluid back through the ABS components and the long runs to the rear.

Always learning something thanks

Ol'Rattler said:

2 or 3 generations ago. I think the intent is to avoid sending old fluid back through the ABS components and the long runs to the rear.

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Go figure. One would think that the ABS module, being right next to the master cylinder, would be the first thing to get flushed. Thanks for the update!

Ok, thanks, couple more questions;

-Within the brake bleeding sequence when do I bleed the clutch unit?
- How much brake/clutch fluid should I get (I could look it up, but I should get extra to make sure the power bleeder remains full). - Never mind, I saw that the clutch is last in the sequence....so I assume that's a two person part of the job because someone needs to pump the clutch?
- Any brake/clutch fluid brand preference? I've been sticking to Liquid Moly for all other services up to now.

I never needed to pump the clutch when flushing in my 2010, fluid flowed until it came clear, maybe I missed some fluid by not doing this procedure, but it was nice seeing milky fluid turn nice and clear after 1 cup or so.

For the clutch - the same 29psi, open the bleeder 1/4 turn, pump pedal by hand very quickly from stop to stop 15-20 times, close bleeder, pump with foot an additional 10 times. A second person helps here simply for the amount of fluid that continues to bleed out as you run from the cabin to under the hood to close the valve! I purchased Pentosin DOT-4 (you can use the LV low viscosity as well). 1.2L is the system capacity, I would buy two liters just in case.

I've bled the brakes on a 2015 TDI and it was no different than any other car. I used a motive products power bleeder, at 12 PSI.

I pushed 1 liter of fluid through the system. I didn't bother with the ABS unit at all. I think replacing all the fluid in the reservoir and brake calipers will go a long way towards preventing moisture build up and corrosion in the system.

They say 3 years the first time, and every two years after that. I assume the reason for this is the first time all the fluid is new and after that the fluid is only partially new.

I'm just going to continue to push a liter through the system every two years from now on and I'm expecting everything to last a long time. This has worked well for my MkIV Golf. After nearly 14 years I'm still on the original master cylinder, ABS unit, front calipers, and the rear calipers only needed replacing due to the parking brake mechanism (which is not hydraulic).

It's a simple job and if done regularly should greatly extend the life of your brake system components.

Another thing to note is the clutch pick up is higher on the reservoir than the brakes, so after some pad wear the fluid level will be down and you may suck air for the clutch.

Also on my previous comment about the clutch, I did use a power bleeder that I fabbed with a garden sprayer and 3rd party reservoir cap, it kinnda worked, the cap leaked a little bit, but it was about $25 or so.

Thanks for the input, 3 years for me is next March.....I'll probably do the service on a rainy Sunday in October or November at work. In the meantime if anyone thinks of anything else, please post.

clutch unit

Anyone have any good pics of accessing the clutch unit to bleed?

Thanks

The bleeder is under the air intake.

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-clutch-delay-valve-removal/

PaulL said:

The bleeder is under the air intake.

https://www.autoinstruct.com.au/man...mk7-golf/mk7-golf-clutch-delay-valve-removal/

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Great little write-up. I never removed that valve when I changed my clutch because I don't mind the feel of the system as is.

Also, should not remove the air filter unless you plan to replace it. Once you remove the N75 vacuum dump hose, the MAF connector, and the front bits of the intake snorkel, you can simply pull up on the box as a unit. They are similar to how the engine cover is pulled off, but a bit more stubborn with the thicker rubber that I'm pointing to. There are three posts that it pops onto.



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Thanks.....I got the bleeder unit from ID parts.....little concerned that specs call for 29psi and the bleeder unit only goes to 30psi.....

I felt the same way, but it worked out just fine for me. My bleeder only goes to 30psi as well. Curious the difference from previous generation cars only needing 14psi (1bar) to doubling it to 2bar!

I just did mine, used a mityvac to suck out the reservoir, (it was pretty dark) and the power bleeder to bleed, lf,rf,lr,rr. I went by IDparts warning to keep it around 10 psi and it seemed fine, I noticed the fluid coming out of the calipers was very fresh almost new looking, but the stuff comming out of the clutch was even grosser than the reservior, lots of particulate, blackish green, and something that seemed to bead on the surface of the fluid. Im doubtfull I got my abs pump flushed in any meaningfull way, but with as clean as the stuff comming out of the calipers looked I'm not super concerned. Im at 205000 miles, I'm figuring on geting one more timing belt change in her, hoping for north of 300k before its not economically viable to keep it going. As I do all my own mechanic work, and so far parts are running less than 1000$ per anum its still a very economical ride.

FWIW, VW specifies DOT 4 Class 6 (Low Viscosity) fluid only.
Some choices:

ATE DOT 4 SL.6
Pentosin DOT 4 LV
Motul DOT 4 LV
VW DOT 4 Class 6

so do you bleed the clutch first before the brakes or after?

Prob doesn't matter, on the mk5 the pick up on the MC for the clutch was higher than the ABS unit. just make sure you have nice clean fluid at the proper level in the MC first, so you could flush the MC clean by doing the brakes first, then do the clutch.