Replacing brakes on Audi A3

p to the e · 15-04-2015 01:39PM #1

Hi all. I'm planning to replace my brake pads on a '04 Audi A3. Should I replace the discs/callipers at the same time? Is it okay to replace two at a time i.e. replace two front then two back a few days later? Anything to watch out for?

I've replaced them on a mondeo before so it's my first time doing it on the A3. Thanks for any help.

biko · 15-04-2015 03:57PM

You don't have to replace discs or calipers unless they show issues. Id the discs are smooth they are fine. If there are grooves or an outer "lip" they may need changing too.
Calipers last many years and usually only need to be changed if they are sticking.

Replace the front pads first and then rear pads at a later point, that's fine (as long as they are replaced in pairs).
The fronts are used more so sometimes only they need to be changed.

Nino Brown · 15-04-2015 04:03PM

You might need VCDS to do the rears, I'm not 100% on that, so check it out.
I just had mine done, and they did them all together.

Tropheus · 15-04-2015 11:18PM

Nino Brown wrote: »

You might need VCDS to do the rears, I'm not 100% on that, so check it out.
I just had mine done, and they did them all together.

I would doubt that you need VCDS on an 04 A3. What's that to do with - the electric handbrake?

16-04-2015 10:34AM

Tropheus wrote: »

I would doubt that you need VCDS on an 04 A3. What's that to do with - the electric handbrake?

Electric hand brake yes. To let the calipers back all the way for the new pads/discs

Nino Brown · 16-04-2015 03:39PM

Tropheus wrote: »

I would doubt that you need VCDS on an 04 A3. What's that to do with - the electric handbrake?

Yeah, it may not even have an electric handbrake though. I don't know if they were as common in 04.

p to the e · 16-04-2015 08:57PM

Thanks for the tips lads. I've been looking around a few other places and there doesn't seem to be any mention of the VCDS (VAG-COM) for an 04 A3. I've never messed with it so hopefully it doesn't come up. Most videos, articles mention it on newer models.

Regarding the calliper piston, any tips for getting it back in? I might have a C clamp around here somewhere so that might work but if not any tried and tested methods?. Should I open the bleed valve when pushing it back in? In some videos they do it and in some they don't.

16-04-2015 10:00PM

You need a rewind tool to push the rear pistons back. Available in most motor factors for about 20 euro.

jca · 16-04-2015 11:24PM

p to the e wrote: »

Thanks for the tips lads. I've been looking around a few other places and there doesn't seem to be any mention of the VCDS (VAG-COM) for an 04 A3. I've never messed with it so hopefully it doesn't come up. Most videos, articles mention it on newer models.

Regarding the calliper piston, any tips for getting it back in? I might have a C clamp around here somewhere so that might work but if not any tried and tested methods?. Should I open the bleed valve when pushing it back in? In some videos they do it and in some they don't.

On the front pads its best to clamp off the flexi hose with a proper hose clamp, open the bleed nipple and then retract the piston. I know it sounds a bit overkill but prevents any dirty fluid making its way into the abs module which could be nasty.

p to the e · 17-04-2015 04:52PM

Am I right in thinking that if I don't open the bleed valve, when retracting the piston, brake fluid will spill out of where you put it in, provided I don't clamp the hose?

17-04-2015 05:00PM

p to the e wrote: »

Thanks for the tips lads. I've been looking around a few other places and there doesn't seem to be any mention of the VCDS (VAG-COM) for an 04 A3. I've never messed with it so hopefully it doesn't come up. Most videos, articles mention it on newer models.

Regarding the calliper piston, any tips for getting it back in? I might have a C clamp around here somewhere so that might work but if not any tried and tested methods?. Should I open the bleed valve when pushing it back in? In some videos they do it and in some they don't.

What worked well for me was a g clamp and a big vise grip. Small bit of pressure on the g clamp and wind the piston back with the vise grip

jca · 17-04-2015 11:53PM

p to the e wrote: »

Am I right in thinking that if I don't open the bleed valve, when retracting the piston, brake fluid will spill out of where you put it in, provided I don't clamp the hose?

Yes, but on its reverse travels the fluid passes through the abs control unit which can cause problems especially if the fluid is dirty in the caliper.

nd · 18-04-2015 09:16AM

rather than clamping off the hose is there any issue with just tightening the reservoir cap and opening the bleed nipple?

cletus · 18-04-2015 09:57AM

Worth regards to rewinding the piston, is possible to use a league of before noise pliers to rewind it. Also if you have the tool for tightening an angle grinder, mitre saw or similar, it may fit the points on the caliper

p to the e · 22-04-2015 10:18AM

So I replaced the front discs and pads. The only issue I had was what I expected and it was getting the calliper piston back in. I popped into a local mechanic and he gave me advice.

Take off the calliper and brake pads whilst leaving the old disc in place. I had a box handy to place the calliper onto as I didn't want any unnecessary strain on the brake fluid line attached to it.
Put the calliper and the inside pad back on.
Open the lid of where you put in the brake fluid so if there's any excess it can overflow. It was also suggested to instead open the bleed valve and clamp the return line to stop dirty fluid returning but I didn't have a clamp.
Place something long and hard (stop sniggering at the back) between the brake pad and the old disc then put some wellie into it. I had my back against a wall and pushed with my foot. After a lot of effort it will move a few millimetres but keep at it. Initially there was a large gap where the outside pad used to be which made it difficult as the calliper was moving inwards when so I was levering so I placed a screw driver in its place to stop the calliper from moving.
Take care not to get any oil on the disc or pad face as this will inhibit your braking.
One of the old brake pads had a sensor wire coming out of it and attached to a sensor so make sure to remove this carefully and replace this with one with another sensor wire. There should be one in your pack of four.
Give the brakes a few pumps before taking it for a test drive.

Is there anything special I can do with the

biko · 22-04-2015 12:35PM

Cool that you decided to DIY it.

I use a C clamp to push the piston back in. They're cheap and makes that bit easier.
Use something to lay over the piston ring like the metal plate in the pick.
It will distribute the pressing force evenly.

p to the e · 22-04-2015 05:27PM

biko wrote: »

Cool that you decided to DIY it.

I use a C clamp to push the piston back in. They're cheap and makes that bit easier.
Use something to lay over the piston ring like the metal plate in the pick.
It will distribute the pressing force evenly.

I might invest in one for the rear brakes when I get around to doing them. I imagine they'd always be handy to have around aswell.

I'm well happy that I did it. I've done bits on cars here and there but I know my limits. For example my timing belt needs doing fairly soon but I'm gonna leave that to the pros. It's funny how you learn as you go. The first brake took me about four hours to do. The second took about a quarter of the time as I didn't make the same mistakes.

22-04-2015 05:56PM

p to the e wrote: »

I might invest in one for the rear brakes when I get around to doing them. I imagine they'd always be handy to have around aswell.

I'm well happy that I did it. I've done bits on cars here and there but I know my limits. For example my timing belt needs doing fairly soon but I'm gonna leave that to the pros. It's funny how you learn as you go. The first brake took me about four hours to do. The second took about a quarter of the time as I didn't make the same mistakes.

The rear brake will probably have to be screwed back in.

biko · 22-04-2015 06:09PM

Yeah, usually the rear needs to wound back.
It's a pain without the right tool so either get the tool or have a mech do the rears.

jca · 22-04-2015 11:10PM

p to the e wrote: »

I might invest in one for the rear brakes when I get around to doing them. I imagine they'd always be handy to have around aswell.

I'm well happy that I did it. I've done bits on cars here and there but I know my limits. For example my timing belt needs doing fairly soon but I'm gonna leave that to the pros. It's funny how you learn as you go. The first brake took me about four hours to do. The second took about a quarter of the time as I didn't make the same mistakes.

You'll need something like this http://www.amazon.co.uk/Laser-1314-Caliper-Piston-Re-wind/dp/B002V72SHS/ref=sr_1_1?ie=UTF8&qid=1429740507&sr=8-1&keywords=vw+piston+rewind+tool for the rear pads.

p to the e · 24-04-2015 12:14PM

jca wrote: »

You'll need something like this http://www.amazon.co.uk/Laser-1314-Caliper-Piston-Re-wind/dp/B002V72SHS/ref=sr_1_1?ie=UTF8&qid=1429740507&sr=8-1&keywords=vw+piston+rewind+tool for the rear pads.

Another trip to the motor factors so. Wouldn't imagine they're too expensive.

biko · 24-04-2015 01:11PM

You can get sets that will work on more than one model. Check with Halfords too.

Replacing brakes on Audi A3

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