mlhj83 Posted February 26, 2008 Report Share Posted February 26, 2008 My car is suffering from very severe brake judder within only ~2000 miles of installing new disc and pads. So severe that my NSF wheel got shaken loose whilst I was on a track. I did try to take it easy on the new disc and pads for the first ~500 miles or so but perhaps I haven't done a proper bed in. So, my question is what bed in methods do you guys suggest. Also, would it be wise to upgrade to a big brake kit for the front e.g. Brembo GT, ECS Stage 5 instead? I have already had my brake fluid changed to Ate Super Blue. Link to comment Share on other sites More sharing options...
Decked Posted February 26, 2008 Report Share Posted February 26, 2008 I don't think I’ve ever run in discs for 500 miles.... Although I say I’ll try! I normally take the car out for a drive, a bit of normal town driving then I'd take it up to about 70 and brake from there, short bursts (not hard) close to stationary then brake hard to a stop, then immediately off the brakes and onto the gas. I'd repeated the process 10-15 times. Provided ur not silly they should be fine. It’s always worked for me. If your on the track, I did cook my stock discs (went blue) so I upgraded to the ECS stage 5's and never had an issue. The Mk5's a heavy lump! Saying this, I've heard they arn't as good n the Mk5... Possibly something to do with the brake servo. Link to comment Share on other sites More sharing options...
Mook Posted February 26, 2008 Report Share Posted February 26, 2008 Changing your brake fluid won't make a sh*t of difference. I never changed the fluid from the stock VW stuff on my R32 and even with long track use around Spa, where you're going from 130+ down to around 20 in some places, the pedal never went long, which is what happens when the fluid gets too hot and forms gas bubbles (sorry if you already knew this!) You also don't need to bed in the ECS Stage 5 disks with Red Stuff pads (the only pads I found that actually worked well). If your wheel bolts came loose on a track day, I would say they weren't torqued up properly before you went out? If you're bedding in new pads, just take it easy for the first 250 miles or so. If you're bedding in new stock disks and pads, take it easy for the first 500 miles, then do five 70 to 20 stops to bed them in - all this is doing is getting the pads warm enough so they scrape off all the uneven surface and match the surface of the disk. HTH Link to comment Share on other sites More sharing options...
mlhj83 Posted February 26, 2008 Author Report Share Posted February 26, 2008 Cheers. Yes, I know that brake fluid doesn't make a difference but I do experience increased pedal travel before I feel the brakes bite, hence the change of brake fluid. With regards to big brake kits, would you recommend them, or is a more abrasive pad like Red stuff coupled to the oem Mk5 disc sufficient? Am I right in saying that a more abrasive pad would help reduce the chance of uneven brake pad compound deposition on the disc causing brake judder? Link to comment Share on other sites More sharing options...
Mook Posted February 26, 2008 Report Share Posted February 26, 2008 Red Stuff pads will kill your stock disks (very abrasive) and they still fade on the stock disks (I tried them on my third set of stock disks before the ECS Stage 5 upgrade). You shouldn't get "brake pad compund" (a.k.a. brake dust ) deposits on a disk causing judder - it should all dissipate onto your wheels, calipers etc. It'll judder due to either a warped disk, a loose caliper or a fault in the servo (extremely unlikely!). HTH Link to comment Share on other sites More sharing options...
mlhj83 Posted February 26, 2008 Author Report Share Posted February 26, 2008 Cheers. This is going to be very expensive... Link to comment Share on other sites More sharing options...
Timski Posted February 26, 2008 Report Share Posted February 26, 2008 This might seem like a silly question to most on here but why does brake fluid get hot? Link to comment Share on other sites More sharing options...
Mook Posted February 26, 2008 Report Share Posted February 26, 2008 Not a daft question at all! When you brake, the pads against the disks generates heat through friction. When you're on a track, you're braking very hard for most corners, generating a lot more heat than you ever would on the road. Even if you have to do an emergency stop from big speeds, you'd not generate as much heat as you would in a few corners of a lap of a track. The heat transfers from the disks and pads into the calipers. It'll take the easiest route it can - brake fluid warms up a lot easier than metal calipers. Then, a bit like water, when it boils, it turns to gas, so it's a bit like having air in your brakes (like you do before you bleed them). So your pedal "goes long", i.e. you have to press it to the floor and you're lucky if you have any brakes at all. This is very different to brake fade, which is caused by the pads getting too hot against the disks, and they produce gas, which gets trapped between the pad and the disk, so you've effectively got nothing causing friction between them to slow you down. Hope this lot makes sense Link to comment Share on other sites More sharing options...
v6tas Posted February 27, 2008 Report Share Posted February 27, 2008 [ QUOTE ] Not a daft question at all! [/ QUOTE ] The only daft question on this forum is the one you dont ask ive found Link to comment Share on other sites More sharing options...
Mook Posted February 27, 2008 Report Share Posted February 27, 2008 Which question was that, then..? Link to comment Share on other sites More sharing options...
Timski Posted February 27, 2008 Report Share Posted February 27, 2008 Cheers Mook - very well explained. (I didn't know brake fade was caused by gas either) - interesting stuff. Link to comment Share on other sites More sharing options...
petsy Posted February 27, 2008 Report Share Posted February 27, 2008 [ QUOTE ] I didn't know brake fade was caused by gas either [/ QUOTE ] so don't pass flatus when driving... Link to comment Share on other sites More sharing options...
Gti_Fly Posted February 27, 2008 Report Share Posted February 27, 2008 [ QUOTE ] My car is suffering from very severe brake judder within only ~2000 miles of installing new disc and pads. So severe that my NSF wheel got shaken loose whilst I was on a track. I did try to take it easy on the new disc and pads for the first ~500 miles or so but perhaps I haven't done a proper bed in. So, my question is what bed in methods do you guys suggest. Also, would it be wise to upgrade to a big brake kit for the front e.g. Brembo GT, ECS Stage 5 instead? I have already had my brake fluid changed to Ate Super Blue. [/ QUOTE ] You shouldn't get anything shake the wheels off, brake judder can't be that bad on its own - something else would have been wrong to cause that. maybe incorrectly torqued up wheel bolts for example, The wheel bolts actually hold/clamp the brake discs onto the hubs! Brake disc warping can occur when the brakes are worked very very hot (driving like a maniac!) and then you leave the brakes ON or handbrake ON afterwards without letting the super hot discs to cool down first. As they cool, the clamped brake pads can leave deposits or traces of friction matter on the disc face. In extreme circumstances the discs can be minutely bent as the metal disc is very hot, and the calipers are bending the disc out of shape (in microscopic levels). It's sometimes possible to rectify the problem by skimming the discs, and also replacing the pads if need be. It would be unlikely that the discs were fitted poorly, and the hub surfaces not cleaned properly if done by proffesionals. I've changed both front and rear brakes on my car without any issues. Are u running standard brake pads? If you're gonna tell me you're running EBC pads of some sort, then I'm sure the discs have got pad contimination Link to comment Share on other sites More sharing options...
mlhj83 Posted February 28, 2008 Author Report Share Posted February 28, 2008 [ QUOTE ] You shouldn't get anything shake the wheels off, brake judder can't be that bad on its own - something else would have been wrong to cause that. maybe incorrectly torqued up wheel bolts for example, The wheel bolts actually hold/clamp the brake discs onto the hubs! Brake disc warping can occur when the brakes are worked very very hot (driving like a maniac!) and then you leave the brakes ON or handbrake ON afterwards without letting the super hot discs to cool down first. As they cool, the clamped brake pads can leave deposits or traces of friction matter on the disc face. In extreme circumstances the discs can be minutely bent as the metal disc is very hot, and the calipers are bending the disc out of shape (in microscopic levels). It's sometimes possible to rectify the problem by skimming the discs, and also replacing the pads if need be. It would be unlikely that the discs were fitted poorly, and the hub surfaces not cleaned properly if done by proffesionals. I've changed both front and rear brakes on my car without any issues. Are u running standard brake pads? If you're gonna tell me you're running EBC pads of some sort, then I'm sure the discs have got pad contimination [/ QUOTE ] I basically ran the new set of oem disc and pads in for around 500 miles by braking lightly to moderately. I never leave my foot on the brakes longer than needed and I do follow the warm up and cool down procedures for track work. But it seems that these particular set wasn't up to the job, which I found very strange. It's with VW at the moment to see whether any other component is to blame or that I just have a bad set of discs and pads. That said, I was already experiencing slight vibration under braking after I went on road trip to the Isle of Man just before the trackday. I was braking down from ~110-120mph quite frequently for a good couple of hours whilst on the Isle of Man, but I did let the brakes cool periodically and I definitely don't leave the handbrake on after a hot session. But I guess you are right about the wheel bolts; they were probably slightly loose and the brake judder probably exacerbated it. Link to comment Share on other sites More sharing options...
Gti_Fly Posted February 28, 2008 Report Share Posted February 28, 2008 Let us know how you get on. good luck Marcus Link to comment Share on other sites More sharing options...
mlhj83 Posted February 28, 2008 Author Report Share Posted February 28, 2008 Cheers. Might be looking to upgrade the fronts to the Brembo GT 4 pot if need be. Was thinking of the Tarox 12 pot and 350mm disc but apparently APS said they aren't really good, which is very surprising as I thought Tarox are meant to be amazing... Link to comment Share on other sites More sharing options...
Gti_Fly Posted February 28, 2008 Report Share Posted February 28, 2008 TBH I've driven my friends mk5 often enough, and I find the brakes to be perfectly able for fast road use. I'm not sure for track use, as I've never been on track. I've driven subaru's with OEM Brembos, and they are simply awesome. They never seemed to run out of power, no matter how fast you were going, and I just love the Hard pedal feel you get with Brembos. If the aftermarket Brembos did that to the Golf, then I'd go for it myself. Have to drive one for myself before I'd take the plunge. that would be my suggestion for you before shelling out over 1k Link to comment Share on other sites More sharing options...
mlhj83 Posted February 28, 2008 Author Report Share Posted February 28, 2008 I would love to able to try a Mk5 with Brembo GTs on but seeing as they cost a bomb, it'll be difficult to find one that has them fitted. So here goes: "Does anyone out there have a Mk5 R32 with Brembo GT brakes!?!?" Link to comment Share on other sites More sharing options...
RedRobin Posted March 2, 2008 Report Share Posted March 2, 2008 Hi Marcus - You're welcome to a drive of my Mk5 GTI with AP racing 4-pots but I guess that would only give you a 'feel' of another brake system on an irrelevant car for your purposes. They are said to be similar to the Brembos but I may be totally wrong there! This is an excellent thread (Mook ) for brake info. I've noticed that my front discs are looking fairly 'glazed' but their performance is as good as ever. My driving style never 'trails' the brakes - I'm usually hardly using the brakes at all except on a harder drive. Being 60yo and 'old skool' I am in the habit of anticipating and coming down the gears before braking. Any comments on my glazing would be welcome . [see you at Portchester] Link to comment Share on other sites More sharing options...
mlhj83 Posted March 2, 2008 Author Report Share Posted March 2, 2008 Cheers Robin! But I don't think I'll be getting the brembos for now as the upcoming Mk5 R32 specific kit is projected to cost around 2800 according to brembo. I too drive preemptively rather than reactively for the majority of the time and I'm relatively gentle on the brakes but I think that either I haven't bedded them in properly (although I did take it easy for the first 500miles) or the discs might have been faulty from the start, which was further exacerbated when I took it to Isle of Man for some proper caning. Will be off to APS in a weeks time to have the discs and pads replaced and have the cams done too. Link to comment Share on other sites More sharing options...
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