UK-POLOS.NET - THE VW Polo Forum

Hi all,
Problem with my partners 2016 Polo GTI.I was in traffic the other day, I got a noise from the passenger side like break caliper sticking. I know on this car it has break assists, could it be down to this, as I am not to sure how it works. What happen was I did like 60 miles on motorway adv 80mph then hit some traffic then after 5 min stop an starting, I got a whineing noise from passenger side. I am thinking passenger rear as the break assist. The car has just done 42000 miles. Also about 2000 miles ago I had to change the rear tyres as one was out of shape. The orginal Bridgestone still had 3m left. The noise was like the wheel was going to full off.. also my partner said it has made the noise before just seems random and she is no help. The car was serviced 1 week ago they said rear pad was getting low and a lip on the disc. Yet nothing else and noise was there before just she did not say to me

when was the last time the brake fluid was changed? i had the exact same problem on my 9n3 due to not changing the fluid often enough.

i think it's 3 years after manufacture then every 2 years

Was changed in the service, just had a major service.

is that the first time? do they actually do the brake fluid on a service as i have had to request it in the past.

I'd be taking the rear brakes apart to see what has been going wrong, maybe just needs a strip down - clean up - lub where required and reassemble.

If you don't know how to do that, take it back to that garage ASAP.

Its only done on a major service. Yet got it changed 2 years ago as well at vw as was not done in the last 3 year one so I was told by then, When I got the air con serviced as was told that too was not in a normal service package.

I will change the rear disc and pads, as they are low and discs are liped, when I do the rear breaks I normally clamp and open the bleed nipple as I rotate the caliper. Do I need to disable break assist or anything else I need to know, I did my break course many moons ago now, but unsure with break assist.
Reason I question the break assist is that it only seems to happen when I've been in traffic for a bit like it's not releasing.

Was thinking of getting brembo high performance groved discs and pads?

Or sod all that and take it back to them to look, it's still under warranty?

Unless I'm reading this wrongly, always brake service is outside of any VW dealership service, minor or major/inspection. What they will do is to give the brakes a safety "visual once over" without removing any wheels - if they don't like what they see/hear, they will either contact you to get authorisation for carrying out extra work at extra cost, or advise you at the collection time to book it back in for brake service/repair.

I would never spend big money on rear discs and pads, the brakes at that end just don't get handed over enough work for them to stay in good condition they always seem to be doomed to need replacing after maybe 6 years or 60K miles due mainly to corrosion and general nastiness.

Thanks for the reply, the oem rear discs have just done 42k, so are less than I expected. I Will be putting high performance disc on the front too, yet the front are in a lot better state to the rear discs, from basic look and feel.
Pads I will prob just look for a soft compound pad, yes more dust on wheel but less burn on the disc. Yet i'm not sure on compounds as not been in trade for some time, I am a carer now. Maybe people here will know and help me. The high performance discs from euros are quite cheep too.

Well, i had a bitt of issues with mine. All new was put on ( discs, pads), and after some while the outer pad wasnt contacting the rotor.
I greased the sliders and, mating surfaces with ceramic grease, and it was working for a month.
Then I decided to do a full bleed, the oil in the rear brakes was awful, and had a bit of dirt. Now it works like new, and the handbrake feel is so good now.

Also, you have a 13 mm bolt, that holds the latch for the cabe. You can work it a bit back and forth with some penetrating oil to make the caliper release when out the handbrake down.

That sounds more like the pistons are sticking in the calliper bores, I've always thought that the rubber seals harden up over time and at some point the smart idea is to replace the seals and dust covers, and hopefully the pistons just need cleaning up, if they have any corrosion on them they will either start sticking again of rip the surface of the seals.

The fact that you said that the hydraulic fluid had bits in it means that the seals are hard and bits are being ripped of them. I replace the brake fluid every 2 years after the car is 3 years old, which is the point for the first fluid change, and the fluid that I remove is as clean as the new fluid I add into the system.

Years ago many of us left the brake fluid in the system for too long but it was easy to see when you had flushed out the old fluid because it looked darker than the new fluid!

Well my plan is to change the disc and pads on the rear, and check the caliper, if any sign will then book in under warranty. This way they dont give me the breaks are low and could be that. Any ideas for soft compound rear pads?

Yet will look in to the break assist, guess it works of the servo, so vac pipe. Yet car can tell when on a hill too yet happen when road is flat.
Also after the torque for the caliper mount bolts and caliper to housing bolts for the rear.

The brake assist - is that same as "city braking" if so it will operate via the ABS pump.

Guide pins 35Nm, calliper carrier bolts 90Nm + 90deg, these calliper carrier bolts should not be reused as the "+90deg" means that they have been stretched.

Moving too far away from VW sourced pads and discs will probably mean not much help from your warranty.

Edit:- the calliper carrier bolt torques were sourced from Haynes repair manual, Erwin claims that the torque should be 30NM + 30deg, which might be correct if these bolts have hex heads, but it does seem to be a bit low for brake calliper carrier bolts! So bear this in mind when torquing them up, ie if they have a recessed multi spline etc head on them, Erwin has got that torque wrong by a high way!

Warning:- I have updated the above posting to point out the differing torque values for the calliper carrier bolts!

For warranty wise, maybe. But it's a caliper so if they try be funny I will take further. If it is the problem. Also was told by my vw friend that if disc is worn and pad low the caliper piston can come out a bit far and cause this problem. Should of asked him if brembo was the oem make for vw bits, will do when I see him if I need replace them bolts. At a glance my red caliper look like brembo.
Do you lock thread the guide pins?
Else i prob put oem pads on, as i can get the pads cheeper.

P.s will hassle my vw friend see if that is correct. But big thank you

Blue Loctite, halfords sell "lip stick/pritt stick" versions, for the guide bolts, maybe the pads will come with new bolts which will come precoated with blue stuff.

It would be very useful if your VW mate can confirm which of the torque settings are correct for the calliper carrier bolts. I'll keep an eye open for that info.

I'd guess that in your case RED does not necessary mean Brembo, I think that Skoda tended to use GREEN for performance versions callipers.