Oz Striker Posted July 18, 2013 Share Posted July 18, 2013 Hello everyone, need some advice about the uneven brake wear. I am planning on doing 1 track day a month for the next 12-18 months in the Z, but I've some braking issues come up. I did a full track day at Bedford GT (in UK) on Monday. New OEM pagid pads went in the week before (all i could get my hands on at short notice), however I perhaps could have done a better job bedding them in. The old pads that came out, had about 1mm difference between outer and inner pads, with inners at about 3mm. In the morning session as I started pushing on (max of 4 hot laps), I started to feel the brake pedal soften a little, no worries I came in. Front disc temps in the morning were about 210, in the afternoon about 280 deg C. But on my very last session of the afternoon, in fact I think it was the last lap, the peddle went pretty soft, and I could hear the brakes groaning, the pads had hit the metal wear tab & groaned all the way home! The following day I removed the wheels to get a good look at the pads. There is virtually no inner pad material left at all, and the inner disc surface has as a nice rusty lip on one side and scored on the other. Bedford GT is 4.1 miles long with 5 hard braking zones from high speed, so i can understand going through a set of front pads and the fade issues on a full day there, with the stock Brembo brake discs, pads, lines and fluids. Does that sound reasonable? But the bigger issue is the uneven wear of the inner and outer pads. There is 3mm of brake pad on the left outer, and maybe 4mm on the right outer. The above pics show virtually now pad material left on the inner pads. This is where i really need people powers of reasoning and intelligence!! So I'll give as much info as possible: - Both front disc rotate freely - On my way home after the track day i was concerned that the groaning could be a stuck calliper, so I pulled over and checked the temps, both discs were equal at about 80 deg C - The excessive wear is on the inner pad on both sides. before the track day i check the rear pads, and they had similarly uneven wear, but much less noticeable, <1mm difference - After i had the pads replaced prior to the track day, the brakes squealed like a total pig at low speeds coming to a stop, i presumed the mechanic had just been stingy with copper/anti-squeal grease. What Conclusions can be drawn, what can be excluded? Can i exclude a stuck calliper, given the above additional points. I've had a stuck calliper on the BMW 330i (twice!) and the braking was juddery and one disc/calliper got much hotter in everyday driving. I've read on line in other cars that it's sometimes due to inadequately greased slide pins, bent slide pins or corroded pins. I'm going to get the front discs & pads, as well as all lines and brake fluid uprated, but need to know whats going on before shelling out £££ on uprated brake components. I might have a go at putting the old pads back in, and so be able to see how easily the 4 pistons on each calliper go back in. All opinion and thoughts on the above problem would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted July 18, 2013 Share Posted July 18, 2013 I would just put it down to rubbish pads, rotors, lines and fluid. Once you do a proper upgrade and providing all the pistons are free then all should be good. Remember that the inner rears will always wear faster than the outer rears. Proper bed in is essential as are warm up and cool down laps. Road and Track Brake upgrade kits are in stock and good to go same/next day. Just give me a shout if I can help you further. Alex. Quote Link to comment Share on other sites More sharing options...
Oz Striker Posted July 18, 2013 Author Share Posted July 18, 2013 Remember that the inner rears will always wear faster than the outer rears. Proper bed in is essential as are warm up and cool down laps. Thanks, that's what I'm hoping. But is the inner pad wearing faster a known 350z trait? Its normal on single piston floating callipers like my 330i, where the outer pad has no piston and is "pulled" on to the disc. But i presumed the Z's 4 pot Brembos would mean more even wear. Can you PM me prices for the following front DBA discs, goodridge lines, Front pagid RS29 and ferodo DS2500 pads? Quote Link to comment Share on other sites More sharing options...
cs2000 Posted July 18, 2013 Share Posted July 18, 2013 (edited) Always happens mate, mine were the same, roughly 2-3mm difference on inners compared to outers when I last changed mine. Also, track day on Pagid brakes ! lol That K pin, is it bent, ir just moved over, sometimes the round pins that hold the brake pads rotate slightly and will rotate the K pins with them, shouldn't bend them though. Edited July 18, 2013 by cs2000 Quote Link to comment Share on other sites More sharing options...
Ekona Posted July 18, 2013 Share Posted July 18, 2013 Inner pads wear quicker on every single car ever. I'd be more concerned that you killed a brand new set of pads, but not discs, on one day at Bedford which isn't particularly hard on brakes. I've done multiple days there in multiple cars with varying levels of brakes (including a HR Zed on stock brakes and the MX-5 on vile crappy things) and never come close to killing the pads. Boiling fluid yes, but pads and discs should last more than that, even super soft race spec ones. 1 Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted July 18, 2013 Share Posted July 18, 2013 If you used the £50 pagid pads and tracked them I would expect them to be knackered. However if you used the £600 ones then I would be worried. I am not an expert on tracking as never yet had the pleasure. But I do know a bit about Pagid pads. It still sounds excessive though. Quote Link to comment Share on other sites More sharing options...
Marcus01 Posted July 18, 2013 Share Posted July 18, 2013 Does the inside face of the disc look black coloured compared to the shiny steel look of the outer face of the disc. Quote Link to comment Share on other sites More sharing options...
Oz Striker Posted July 18, 2013 Author Share Posted July 18, 2013 cs2000, thanks for sharing your experience, i find that somewhat reassuring. Yep they were stock, basic pagid pads from eurocarparts! I know, i know what was i thinking?! But I thought they would at least last the day! I'm starting to think that the bedding in procedure wasn't the best. But there aint many places i know of in south london that i can bed the brakes in properly, i ended up heading out about 10pm one night and headed towards A23/M23. Did the best i could, but what I really needed was 2 roundabouts separated by about a 0.5-1 mile straight stretch if road, and just go between them doing the bedding in. I cant think of any other issue that would affect both front brakes in the same way. As for the K-pin, yeh it is bent for some reason, not sure how that could have happened, bit of a puzzler. Quote Link to comment Share on other sites More sharing options...
cs2000 Posted July 18, 2013 Share Posted July 18, 2013 Was the K pin bent before do you know? Could be as simple as it just being bent during a pad install. They aren't very strong as their job isn't to withstand much pressure, just to stop the retaining pin that holds the calipers from wiggling out. Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted July 18, 2013 Share Posted July 18, 2013 Every time my mate gets near my car he beds the brakes in lol. I used to be a executive coach driver/Chauffer and tended to use the gear box and keep the vehicle moving. I have not got out of the habit and hardley ever use the brakes except at lights or the end of my journey. On a trip last week with Brooklands350 when a BMW joined the motorway and went straight across 3 lanes to be in the outside lane. Chris had to brake hard and i was a decent enough distance behind him to have plenty of time to brake. However the peddle was spongy and I am guessing by the marks on the disc, only about 1/3rd of the pad was actually being used! Lesson learnt. Now when I stop at lights or come off motorway I look to see if anything is behind me and do a 60mph hard stop. Interesting thread though Quote Link to comment Share on other sites More sharing options...
Oz Striker Posted July 18, 2013 Author Share Posted July 18, 2013 Does the inside face of the disc look black coloured compared to the shiny steel look of the outer face of the disc. No not black, the pic above shows a rusty lip on inner aspect of one disc, and the other was worse with rusty lip and scoring in the middle of the pad. Why what were you thinking? Quote Link to comment Share on other sites More sharing options...
Marcus01 Posted July 19, 2013 Share Posted July 19, 2013 Any corrosion build up difference on the disc face will give excessive wear. Todays brake technology is for discs to be a soft surface and pads to be a hard surface. Any corrosion is a harder surface than a nice shiny disc so will have a different wear rate. In my experience any corrosion/black scale build up will just eat the pads. Your picture showing a corroded wide band on the inner face tells me there is limited braking in this area but plenty of pad wear putting more load into the area which is clean this will increase the wear. With no wear lip showing on the disc an on car disc skim will bring the surfaces back to equal braking efficiency, even pad wear and optimal performance. multiple piston calipers are designed to enhance brake performance and keep pad pressure equal eliminating unequal pad wear associated with single piston calipers. 1 Quote Link to comment Share on other sites More sharing options...
Oz Striker Posted July 22, 2013 Author Share Posted July 22, 2013 (edited) Thanks for advice Tophooker, but one of front discs is beyond repair, so new discs will be going on. So I thought I would stick my old pads back in just to allow me to get the car to the garage, etc Removed the left front pad and this is what i found, top pic is the pagid pad that was used at the track, bottom pad is the Brembo pads that came out prior to the track day. Note how the brembo's have a backing plate (prob aluminium) which minimise heat tranfer to the piston and hence fluid. The result with the pagids is the piston shape has become heavily imprinted on the back of the pad, to such an extent that i was able to force my finger through. BUT worse was the front right!! I'll let the pictures tell the story, this is how the pads came off, fook!!: Cleaned the inner bores as best i could with disc still in place, but when i replace both discs and pads in the coming days, I'll give the piston bores a gentle clean with some fine sand paper and iron wool. Good news: all pistons went in easily, and its nice to realise that the pads can be changed without having to removing the calliper unlike in the 330ci. Edited July 22, 2013 by Oz Striker Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted July 22, 2013 Share Posted July 22, 2013 cs2000, thanks for sharing your experience, i find that somewhat reassuring. Yep they were stock, basic pagid pads from eurocarparts! I know, i know what was i thinking?! But I thought they would at least last the day! I'm starting to think that the bedding in procedure wasn't the best. But there aint many places i know of in south london that i can bed the brakes in properly, i ended up heading out about 10pm one night and headed towards A23/M23. Did the best i could, but what I really needed was 2 roundabouts separated by about a 0.5-1 mile straight stretch if road, and just go between them doing the bedding in. I cant think of any other issue that would affect both front brakes in the same way. As for the K-pin, yeh it is bent for some reason, not sure how that could have happened, bit of a puzzler. Gatwick North to South terminal:) exactly what you need. Or St Peters Way Junction 11 M25. Turneither left or right. Both will allow you to easily get up to 60mph and brake safely:) 1 Quote Link to comment Share on other sites More sharing options...
Marcus01 Posted July 23, 2013 Share Posted July 23, 2013 The back plate as you call it is a shim to help reduce brake squeal. They are usually stuck on. If you buy pads without this shim clean up the old ones coat in copper slip to help it stay in place as you put the retaining pins in. Better to use an old shim than no shim at all. My advice is to avoid Europarts. Cheap and cheerfull in my book means do it twice. Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted July 24, 2013 Share Posted July 24, 2013 Someone mentioned titanium shims the other day! I just did what the guys on here do. Put some grease on the back of the shims and stick them back in:) 1 Quote Link to comment Share on other sites More sharing options...
Oz Striker Posted July 24, 2013 Author Share Posted July 24, 2013 I think its a little unfair to say Eurocarparts are chea Better to use an old shim than no shim at all. My advice is to avoid Europarts. Cheap and cheerfull in my book means do it twice. I think thats a little unfair on Eurocarparts, they will have a range of items from super cheap to higher spec item eg Meyle HD suspension components for my BMW, and I'd only use Contitech belts on the BMW. Of course they aren't going to have many track orientated items, and you can always throw in more £££ and get a 'better' item. I just assumed (wrongly) that a Pagid item would be close to OEM spec, but also my own fault for not realising the relevance of the shims & that they could come off and be put back on the new pads. However I did pay a garage to do it, but I'd have told them if I knew. But i guess its a learning curve working on an unfamiliar car. Someone mentioned titanium shims the other day! I just did what the guys on here do. Put some grease on the back of the shims and stick them back in:) Thanks, yeh that's what i'll be doing once the DS2500's arrive & i install them myself this time. I'm just glad i asked for my old pads back!! Been reading about the titanium shims, but i have my doubts..... its all very good decreasing how much heat gets transferred to the caliper, but wouldn't that mean the heat is gonna build up in the brake pad?? How will the pad & hence disc cope with becoming hotter?? Or will the increase in pad temp still comfortably be within the operating range of the most brake pad's? (some pads can operate fine up to 400-600 deg C!!) Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted July 24, 2013 Share Posted July 24, 2013 Titanium shims in stock and they work well with the DS2500 pads and DBA T3 rotors. Remember that the DS2500 pads do not have shims and most the OEM front shims are bonded to the pads. Regards, Alex. Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted July 24, 2013 Share Posted July 24, 2013 I got my 2500's of Alex and managed to get the shims of intact. When I next need pads I am going with the expensive Pagids as I have some guys I know with 911's and one with a GTR love them. So I might get the Titanium shims at same time. almost the entire East London St John's Ambulances are running off Pagid rotors and pads so they cant be that bad. Obviously not the cheap ones, but middle of the range ones Quote Link to comment Share on other sites More sharing options...
Marcus01 Posted July 25, 2013 Share Posted July 25, 2013 I am sure Europarts do some good quality items. Spending good money rather than skimping is my point Discs and pads can save your butt so always buy the best IMHO. Quote Link to comment Share on other sites More sharing options...
cs2000 Posted July 25, 2013 Share Posted July 25, 2013 When I changed mine I swapped the metal part over, but im guessing you should also swap the rubber backing that was on the brembos, I never bothered Quote Link to comment Share on other sites More sharing options...
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