Rear brake problem?

[Gti Fly]

Hi guys,

today I went to renew the brake fluid and noticed that on one of the rear discs there is a rusty ring all the way around the outer edge face of the disc - we are talking 1cm ring all the way around meaning the pads aren't touching this part.

Any ideas as to why this is happening?

For what it's worth I fitted these discs and pads myself (PAGID parts from Eurocarparts, which I bought over the counter giving them the reg plate)

I'm pretty methodical when it comes to fitting brakes, everything is wirebrushed, and greased (paying lots of attention to the rust where the pads glide along, ensuring that the pads won't get stuck, and can slide easily).

The pad fitment and discs were exactly the same size as the crap that came off, so I can rule out incorrect parts.

Is this a case of a sticking rear caliper? or is there some other issue going on?

I've noticed that on my spirited drive home from work, I can occasionally hear a chug-chug-chug noise from the rear (upon braking) which I now believe is this side's brake getting hot and maybe sticking.

Anyway today I bled the brakes, paying special attention to this caliper. I also took off the pads and caliper, cleaned, de-rusted the guides, re-greased and re-fitted everything again. Hopefully it will sort it?

Also for what it's worth, I've read about fitting additional springs to each caliper to aid the handbrake release mechanism, should/could this also help with the sticking rear caliper?

[rum4mo]

I think that you should cover that eventuality (sticking rear callpers) by buying and fitting the Sharan/Alambra return springs. I have noticed that quite a lot of "older" VAG cars end up with the swept area of the disc being missed at the outer edge, whereas on "newer" VAG cars, the outer area is (just) swept by the pads. I'd think that its a slight mis-match on the set-ups VAG bought in from the brakes people. I would not think that the Pagid discs and pads are wrong as that set up is used widely across the VAG range, if the discs were too big then you would have trouble fitting the calipers back on. I always do my sums (mis trusting old buggar) and check what is currently fitted size wise against my ETOS parts list, and then go onto the sites like Pagid and see if it ties up with what they claim is correct, and also note down any numbers as they should be on teh boxes you buy from ECR and/or GSF - that, if you can do it, can save some annoying re-assembling of old parts and returning to the parts vendor - yes, I've been there and done that!

Also, remember that these rear brakes never get much work to do, so are prone to getting rusted up.

Edited 31 March, 2012 by rum4mo

[Gti Fly]

Thanks for the reply,

Well after today's normal drive to work I can say that the brakes still don't swipe that area of the disc (can still clearly see properly rusted raised metal that hasnt been so much as touched) So cleaning and refitting did bugger all!

WIll this be any sort of MOT failure?

Also, does anyone know what the correct part numbers are for these elusive springs? I'm gonna try to fit some this week

[TriggerFish]

My Golf has this also - same brake setup as the Fabia

[Gti Fly]

Having problems with my rear brakes not sweeping the whole disc face (http://www.briskoda.net/forums/topic/137832-handbrake-cable-issue-on-my-vrs/page__st__150)

So I have fitted these springs today. Hope it will maybe help with the issue above.

Anyway, I ordered

7HO 615 295A (near side)

7HO 615 296 (off side)

total cost around £5 from my memory.

Fitting was a piece of cake. No need to jack up the car (i've got a 1,9tdi), just clumber under the car, locate the holes and stick one end of spring in, and squeeze the spring and slot in the other end. Took about 1min each side.

I'll report back to let you know if it fixes my problem

[Gti Fly]

Well it's been a month with these springs, so probably done 1200 miles or more.

Reported differences:

Brakes still have approx 1cm unswept area on the outer edge of the disc (when viewed through the wheel). So buggered now if I know why this is happening..... Any suggestions?

Other differences:

Handbrake level is ever so slightly harder to pull, I guess that's just the springs. No big deal

Brake pedal seems to have more feel, but it might be in the mind, but they certainly feel more snappy

And the biggest difference, no more brake binding/chugging. I used to get a chug chug chug when braking after a 'sprited' drive from the rear caliper. This doesn't happen anymore. So it might mean that the caliper was previously binding perhaps???

Dunno hard to say, but it certainly don't chug chug anymore

[VWD]

I don't have rear discs on mine, but have the same on my fronts. My MOT place keeps on adding a mention of discs on every MOT, I've had a tyre place try to panic me on wear. My readings on mine ( new =23mm,replace =19) were 20.5 @ 55k. I asked one RAC bloke why, and he reckoned that MOT man had seen the unswept area and decided that in event of VOSA check, he'd need to add asbestos to his pants.Suggestion was to remove excess from outer of disc.

Same( MOT) bloke thinks that my exhaust has a heatshield. Again ,might fool little old ladies, but to someone who's rebuilt a few engines, it's called cowboying.

Edited 4 May, 2012 by VWD

[rum4mo]

I thought that I pointed you in the right direction with this problem, ie its mainly down to the way that VAG mis-matches its kit of brake parts - so you will always get an unswept outer portion of the disc. If that is wrong, then you would need to get rid of the raised rusted portion back down to same level as the rest of the swept area - and fit new pads, as these rusty portions are harder than the friction material so you will never "clean" that stuff back down by hard braking.

[rum4mo]

I don't have rear discs on mine, but have the same on my fronts. My MOT place keeps on adding a mention of discs on every MOT, I've had a tyre place try to panic me on wear. My readings on mine ( new =23mm,replace =19) were 20.5 @ 55k. I asked one RAC bloke why, and he reckoned that MOT man had seen the unswept area and decided that in event of VOSA check, he'd need to add asbestos to his pants.Suggestion was to remove excess from outer of disc.

Same( MOT) bloke thinks that my exhaust has a heatshield. Again ,might fool little old ladies, but to someone who's rebuilt a few engines, it's called cowboying.

.

Yes it does seems that VOSA are making MOT places issue advisories for brakes if they are more than 1 month or 1,000 miles old! Similarly, orange bulbs get advisories even if they have been replaced the day before, really more than just a bit annoying - makes the whole MOT thing sound a bit Mickey Mouse

[Gti Fly]

I thought that I pointed you in the right direction with this problem, ie its mainly down to the way that VAG mis-matches its kit of brake parts - so you will always get an unswept outer portion of the disc. If that is wrong, then you would need to get rid of the raised rusted portion back down to same level as the rest of the swept area - and fit new pads, as these rusty portions are harder than the friction material so you will never "clean" that stuff back down by hard braking.

Hi,

Thanks, I was sort of hoping that it wouldn't be down to mismatching. But I guess it's the most logical explaination in this case. The brakes seem to be working fine, pedal feel is good, and braking power is more than ok for what the car is.

I just hope it doesn't fail an MOT