# Brake Replacing help on 02 Jetta 1.8T



## neonryder (Apr 28, 2008)

I am new to this forum and even newer to doing things on my car. After years of forking over loads and loads of money to the dealership, I finally convinced myself to do the work. My rear brake pads needs to be replaced and I am hoping to tackle it this weekend. I bought the piston retracting tool from ECS tuning after reading numerous threads on this forum. I am not clear on the bleeding of the brake fluid. Can anyone help? Do I need to bleed it to back the piston or will the piston just retract without bleeding the fluid. In addition, how does the ABS come into play with the overall braking system and do I need a VAGCOM to get around the ABS? Please help, I am feeling a bit overwhelmed.


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## macachicle (Apr 29, 2008)

*Re: Brake Replacing help on 02 Jetta 1.8T (neonryder)*

The bleeding is done after you have retracted the pistons and installed the new pads. The hardest part there is the actual retracting of the pistons because it requires a fair amount of pressure. Without the tool it is almost impossible. You might want to unscrew your brake fluid reservoir because by retracting your pistons you are reducing some of the area available to hold brake fluid so expect fluid overflow in the reservoir and find a way to extracting it. Maybe a pump or something to take some out of the reservoir before you retract your pistons. Before you install the brake pads make sure they have a silicone lining in the back to prevent squealing. If not you can get buy a tube at any auto parts store and apply some yourself. It is safe now to install the pads. After you install the pads and assemble the brakes there is a bleeder screw that you have to just loosen enough to let the air bleed out of the caliper. For this it is very helpful to have a helper because someone needs to depress the brake pedal repeatedly (3 or 4 times) with the screw tight and then stop and hold the pedal down while you loosen the screw to let the air out. Once you see fluid coming out of the bleeder screw you should tighten it again. Seeing fluid coming out is an indication that the air has bled out and all you have left is fluid. This process should be repeated 3 or 4 times because there could be some air trapped in the lines and you want to make sure you get all that air out. Make sure you have the appropriate level or brake fluid in you reservoir and screw that cap back on. After you have finished and before testing with the car on make sure you step on your brake pedal 3 or four times to make sure you have built up enough pressure in the system so the brakes can function properly. I wouldnt be surprised if i did but let me know if I left anything out.


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## neonryder (Apr 28, 2008)

Thanks for that. If you have left out anything, I wouldn't know till I actually tackle this project. Just out of curiosity, why would air get in the line? I am changing the caliper and thus in theory wouldn't have open the brake line and expose to air except for opening the reservoir and syphoning the excess fluid. Someone at worked spooked me in saying that I would actually introduce air in the process of bleeding it. Please clarify.


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## neonryder (Apr 28, 2008)

Sorry just noticed a typo. I am not chaning the caliper. Only brake pads and the rotors.


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## macachicle (Apr 29, 2008)

*Re: (neonryder)*

The brake fluid in your system can absorb water. This water very often gets into the system as a result of condensation due to heat, from when the brakes or hoses get hot. Water can have dissolved oxygen in it, which, when hot, expands into small air-bubbles. When there is enough air in your system your brakes start feeling spongy and not performing properly due to the air being compressible. To be honest with you I have changed my brakes without bleeding my system many times and have had no problems. The only reason people bleed their brakes when they change their pads is because it is recommended to do that (every year) close to the same time that you would normally change your pads. I try not to get dirty with brake fluid so most of the time I never bleed.


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## neonryder (Apr 28, 2008)

I like that answer. I think I will let one of those lube people to do the dirty work of bleeding the brake fluid. Thanks for your help. Will let you know how it goes.


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## nukewolf (Jun 8, 2004)

*Re: (neonryder)*

When you retract the piston in the caliper open the bleeder screw a little. Two reasons: 1 easier to pussh the piston, 2 wont mess up the abs valves in the system. I have haerd of individuals doing a brake job and not opening the bleeder only to have the customer came back later with the abs light on. Just a little helpful hint.


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## neonryder (Apr 28, 2008)

Thanks Nukewolf. I was wondering how this would have an impact on the ABS and that makes sense. If that's the case, then the fluid will just drain out of the bleeder and wouldn't go back into the master cylinder, right?


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## Old Dude GTI (Dec 25, 2007)

But if you open the bleeder valve won't you introduce air into the system, making bleeding mandatory?


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## nukewolf (Jun 8, 2004)

*Re: (Old Dude GTI)*

you just crack the bleeder with slight pressure on the piston. The fluid will drain out of the bleeder not allowing air to enter. Ive never had a problem with air entering the system.


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## hunbarian (Dec 31, 2007)

this is cool I'm gonna try the pad replacement next time. Does anyone have a DIY with pictures for pad replacement front and rear my car is a 2002 GTI vr6 24 v ?


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## The Critic (Oct 12, 2006)

*Re: (hunbarian)*

While it won't be specific to VWs, I have a video tutorial that I made with a few other people on a rear brake replacement for a G35. Aside from the different method of retracting the pistons (I think yours are threaded), it should be roughly the same procedure.


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## bikervw (Dec 20, 2008)

*Re: (nukewolf)*

By applying slight pressure to the piston and cracking open the bleed valve to avoid ABS issues, do you open the brake fluid reservoir while you do this or do you keep it closed?


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## DC Jetta Guy (Jul 31, 2004)

*Re: (nukewolf)*

Why would you want to crack your bleeder valves to push in caliper pistons? That makes no sense and seems like you're making double work for yourself. When the caliper pistons are pushed back in it will simply raise the brake fluid level in the reservoir back to the original level and there will be no air introduced into the brake lines. Just take the top off of the reservoir and keep your eye on the level.
I replaced pads and rotors on my 05 GLI about a year ago. The front caliper pistons push in quite easily with a standard c-clamp. Bolt up the new rotors and only push in your pistons a little at a time until the pads will fit onto the rotor. The rears work the same except that you need this tool as the rear pistons are threaded:
http://www.ecstuning.com/stage....html
I've never had any ABS anything problems after the brake job - straight bolt everything on and go with it. I would get your pads and rotors on first before messing with bleeding anything and if you've never done brakes before leave the bleeding to somebody else. I'd be surprised if you even had to fool with bleeding anything.


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