Front Brake Replacement FOUND

[DeeAitch]

Sorry Alan, slip of the finger Should read M12 x 1.5 x 40 :-[

[Matthew Welsh]

Go with some of the beautiful polished SS ones from South Coast Stainless.  They have this size.

[DeeAitch]

Alan, Hold the bus! <br>Just checked and Metric fine series is 1.25 pitch for M12 ???, (as my original post coarse series is 1.75). Will check actual bolt again tonight, with a works "verynear" this time instead of the skool ruler! <br>Sorry for the confusion.

[ESM]

No worries Dave, thanks for going to the trouble.  :)

[Doug]

Hold on there . . . <br><br>When I bolted up the new Wilwood front brakes I needed a new bolt for the caliper bracket. My memory is that it was M12 X 1.5 pitch. Yes the "standard" pitch is 1.75, and the "fine" pitch is 1.25, but the proper was 1.5--which is supposedly a common "automotive" pitch--go figure.  Anyway you can always bring the old bolt and match the pitch up with the appropriate nut! I can re-measure mine if you need me to, but I did buy 40mm bolts, which were probably about 5mm longer than the stock OE ones . . .<br>

[DeeAitch]

M12 Coarse series = 1.75 pitch<br>M12 Fine series = 1.25 pitch<br>Checked again last night and we defo have M12 x 1.5 pitch. As above this is a typical thread in the Automotive business - stops us using any old monkey metal bolts in critical areas.<br>I still have the old bolts and they are 40 long. Vectra were exactly the same except rusty as they are not protected!<br>Alan, let me know if you have trouble sourcing the length you need and I will see what can be done here.<br>This may be obvious but you should also get some new copper washers for the brake unions.

[ESM]

Ok I'm confused  - Doug says he got new 40mm bolts that were around 5mm longer than the originals and Dave says the originals are 40mm long ??? So with my spacers I need either 40mm or 45mm long bolts.... Which is it? <br><br>Come on guys duke it out [smiley=fight.gif]

[DeeAitch]

Originals are 100% 40!  [smiley=2gunsfiring_v1.gif]<br>I have 2 sets so if you need 40 you can have my spares If you fit them in Washington then we can easily cut to length so go for 45, 50 or whatever you can get ya mits on (but remember longer bolts are not fully threaded).

[Doug]

[quote author=ElanScanMan link=board=suspension;num=1057127333;start=105#106 date=10/28/03 at 01:13:53]Ok I'm confused  - Doug says he got new 40mm bolts that were around 5mm longer than the [/quote]<br>Doug's memory is fading . . .  ::)<br>I measured the OE bolt and it is 40mm; thus I must have purchased 45mm replacements.<br>

[ESM]

[quote author=ElanScanMan link=board=suspension;num=1057127333;start=105#106 date=10/28/03 at 01:13:53]<br><br>Come on guys duke it out [smiley=fight.gif][/quote]<br><br>That'll be you on the right then Doug  ;)

[Gregor]

Today I tried to fit the Astra GSI (52mm piston) caliper on the Elan. The central position (to the disc..) was ok, but the disc should have a minimum diameter of 260mm or 262mm. I can't belive that a "normal" brake caliper out of any Opel/Vauxhall will fit exactly.... That is also the reason that the normal upgrade kit for the Opel Corsa, Astra and so on will NOT fit the Elan.<br><br>The Elan's caliper is different from the more modern Opel calipers. The old style calipers are used by Opel till 1988/1990.... Normally with 20mm discs, only a few models in this years used 24mm discs. But this models should have used the modern calipers (no guaranty for this...).<br><br>But for me the never ending "GSI" discussion is over now !! <br><br>I think there are three solutions for this Problem. <br><br>1: Try to get a bigger brake disk for the "GSI" caliper (worst solution I think...)<br><br>2: Buy a Hi Spec Brake Kit with 285mm or 300mm discs....<br><br>3: Build my own upgrade kit with Porsche brake discs and   brake calipers with a special adapter. See the first steps here: http://de.f1.pg.photos.yahoo.com/ph/mr_elan2000/lst?.dir=/Lotus+Elan+Brake&.src=ph&.order=&.view=t&.done=http%3a//de.f1.pg.photos.yahoo.com/

[MoltenLava]

I'm not trying to beat a dead horse, but I have a couple of questions.  Please bear in mind that my mechanical knowledge is very small so these questions might sound silly.  I'd just want to have better understanding of how these things work..<br><br>[quote author=Gregor link=board=suspension;num=1057127333;start=105#110 date=11/03/03 at 10:31:46]Today I tried to fit the Astra GSI (52mm piston) caliper on the Elan. The central position (to the disc..) was ok, but the disc should have a minimum diameter of 260mm or 262mm. I can't belive that a "normal" brake caliper out of any Opel/Vauxhall will fit exactly.... That is also the reason that the normal upgrade kit for the Opel Corsa, Astra and so on will NOT fit the Elan.<br>[/quote]<br><br>I know that you have a big problem if the disc is too big for the calipers.  But you are saying disc being too small for the calipers is also problematic?  What sort of issues would you have if the disc is too small for the caliper?  As I read in the previous messages the difference is only 2mm or so, right?<br><br>[quote author=Gregor link=board=suspension;num=1057127333;start=105#110 date=11/03/03 at 10:31:46]<br>Try to get a bigger brake disk for the "GSI" caliper (worst solution I think...)<br>[/quote]<br><br>Why would you recommend against getting a bigger disc?<br><br>Again, sorry if these questions are too naiive.<br>

[Gregor]

[quote author=MoltenLava link=board=suspension;num=1057127333;start=105#112 date=11/04/03 at 14:29:06]<br>I know that you have a big problem if the disc is too big for the calipers.  But you are saying disc being too small for the calipers is also problematic?  What sort of issues would you have if the disc is too small for the caliper?  As I read in the previous messages the difference is only 2mm or so, right?<br><br><br>Why would you recommend against getting a bigger disc?<br><br>Again, sorry if these questions are too naiive.<br>[/quote]<br><br>You will need a bigger disc only in the case if you like to use the more modern Opel/Vauxhall calipers. I think also it is more as 2mm... (see picture). When the pads loock over the disc you loose a lot of the pads surface to bring the brake force on the disc. The pressure is also only in the outer area of the disc, but it should be in the middle of the surface. The newer calipers are a little bit closer to the center of the shaft as the old ones. You can say the Elan uses a new disc with an old caliper. The old caliper is designed for a 246mm disc. For the Elan's setup they moved the caliper (for example) 5mm more away from the center to fit the bigger disc (246mm to 256mm). But I thin to buy new discs and calipers including pads is not really cheap. So the better way (for me) is to spend the money in a "real" upgrade... To change from 48mm to 52mm piston size is not the philosophers' stone...  <br>See picture here:

[Dimitris_GR]

Hi guys.<br>This is my first (actual) visit to the LEC after a long, workfull and flu-full (:() period.<br>Unfortunately, I haven't driven my baby for many kms. My one month Opel Corsa (mod 95) gave me all the lifts I needed (from home to work and back).<br><br>I DO have to say a couple of things, though.<br>First of all, (but the last time I'm saying this for the disbelievers) the Astra Calipers came directly from an Astra GSI, so there's no doubt that they do fit.<br>The most important thing here is that I changed my pads one day, and found that<br>THE PADS WERE ACTUALLY WORE 1mm FORM EDGE.<br>This fact makes me feel silly, because the truth IS that they fit a bit off the discs. So please excuse my insisting on they fit exactly ON the discs. But this doesn't mean that they are bad. In fact they are as good as I previously described them.<br>They DO brake a lot.<br>And I still think that 150 euros (used calipers+half wore pads) is nothing compared  to the great improvement over stock!

[ESM]

That's three cases (Dimitris, Gregor and Dave) where the 260x24mm Corsa discs would fit the bill exactly. No cases (recent anyway) where they wouldn't work so far...

[Dimitris_GR]

Alan, <br>I actually use the EBC tubo grooved disks, that are the standard diameter.

[ESM]

Yeah Dimitris, what I was trying to say was that with the 260mm Corsa discs fitted you would have no 1mm overhang, I wasn't suggesting you had fitted them already. Also the EBC discs are 258mm, which is 1mm bigger in radius than stock. <br><br>

[Dimitris_GR]

Hmmmmmmmmm<br>Did you say Xmass present???  ;)<br><br>No... I think when they'll ware out...

[westonben]

Alan,<br><br>Will the corsa disks will be an exact fit?  I guess there will be no margin at all?<br><br>Ben<br><br><br>(Hmmm, nice shiny disks)