So I broke a disc.....

[rowdytoot]

see pics- off my stock standard, daily driver D40 navara. The discs are 13,000 km old DBA's. Have been running hawk ceramic pads.



http://www.rowdyrallysport.com/stuff/photos/broken_brakes_6.jpg

http://www.rowdyrallysport.com/stuff/photos/broken_brakes_1.jpg

http://www.rowdyrallysport.com/stuff/photos/broken_brakes_2.jpg

http://www.rowdyrallysport.com/stuff/photos/broken_brakes_3.jpg

http://www.rowdyrallysport.com/stuff/photos/broken_brakes_4.jpg

http://www.rowdyrallysport.com/stuff/photos/broken_brakes_5.jpg

So the friction surface has separated entirely from the 'hat'/ hub on the LH disc.

There was no evidence of this happening when it was serviced on tuesday last week.

It just suddenly let go on Saturday night, confused me and the ABS quite a bit when we didn't stop, and the Nav pulled sharply to the Right...

of course there was no obvious movement of the disc until I took the pads out...

Competition Friction are coming to pick up the discs tomorrow, and I assume give them to DBA for analysis.

I'd like to thank my mate Stretch for lending me his spare front discs til this gets sorted!

[JabberWocky]

Jeese that's unusal, never heard of any doing that. What sort of symptoms did it give for you to inspect it? Best of luck with getting them replaced.

[CT]

Holy crap Rowds - that's crazy. I'll chat to my contacts at DBA - see if they know about it yet. I'll wait before upgrading my D40s front rotors for a little while yet....

[rowdytoot]

hey guys.. I had a chat to John at Comp Friction this morning (lovely bloke, buy all the rally car brake pads thru them/bsm.vsport as well) and he said he's never heard of it happening....

Jabberwocky... well it wouldn't stop and it pulled V.hard right under brakes after stopping fine on the trip to my g/fs from meeting Daveee on Saturday night.

I couldn't see anything obvious on sunday AM> so I drove home carefully, and a coupla times when I put lateral load on the LH side there as girndy noises which seemed to be coming from the RH front which I stopped and checked out but couldn't see anything.

So I got home and pulled the RH front wheel off, took the pads out, took the disc off, and all looked good. I did bend the dust shield away from the disc a touch. Put it back together an drove down the street and hit the brakes... the RH front had the ABS kick in, and the LH front did nothing..so I had a mountain of steering lock on to the Left.. ie. no braking on the LH side..

drove the 100 metres home, and pulled the LH front pads out, and noticed that the disc was moving independently of the hub. explained the noises, and the no stopping.... I was suprised when I pulled the disc off, and found it completely separated though. Interestingly I had noticed when i looked through the wheel on sunday Am that the margin between the hat and the friction surface looked like the surface 'rust' was flaking on that side- in actual fact it was the fracture surface where the 2 had separated as you can see in the photos.

CT- mine were one of the 1st few sets cast I reckon, so I suspect a manufacturing fault, coupled with the fact that I don't have a problem braking hard- there is only 1 colour of the temp sensitive paint left on the discs.. and the pads show signs of being quite hot..

oh and I have to say, even with the hawk pads on stock discs, it doesn't stop anywhere near as good as with the DBA ones..

[Zac]

He's never heard of it happening - he hasn't reckoned with a driver like rowdytoot :D

[Steve]

Wheel bearings not adjusted correctly, cornering hard under brake causing pad knock off and or side loading on the disc? May explain that amount of heat. My commodore rotors don't get that hot on the track. Just a thought.

[rowdytoot]

no knock off to speak of, bearings have no play.

it's 2 tonne 4wd, it doesn't corner THAT hard and don't LF brake in it.

The stock Nissan discs I had before were severely heat cracked at 40,000 km on stock pads....

the DBA discs show no sign of heat damage at all. they are fine (aside from the fracture issue)

oh and if you can't get your discs that hot on the track, you're not braking late and hard enough :D:D eheheheh

I've taken discs off the rally car that are completely blued using DS3000 pads with sub 100 hp...

[jezza323]

wow, good thing you got away with it without any damage

[Steve]

oh and if you can't get your discs that hot on the track, you're not braking late and hard enough :D:D eheheheh

That's possible. I've just fitted a bias valve so things may be a little bettr now :D:D eheheheh...

[tut]

just weld it back together like the spanish guy with the mitsu

[Jim]

I'd be making sure you don't have a sticking caliper or stuck slides. If the caliper loads up only one side of the disc you may see the failure you got there.

It could just be a shity casting, but definately check the calipers!

[rowdytoot]

Jim- all checked- pad wear is completely even, and no dramas with the slides at all.

[RB30-POWER]

will be interesting to see if dba come good on this count.

similar story posted elsewhere, new discs, couple of weeks old and one failed/cracked.

seems dba might be going to cheap and nasty china/taiwan production standards these days?

of course with the story i refer to above, it was not their fault, had to be an installation fault etc etc. which is doubtful in my opinion as it ain't exactly rocket science to fit them properly.

but who knows, give them benefit of the doubt in the mean time until we see a much larger failure pattern emerging.

[Jay_G]

Have seen a post on Rexnet with the same thing happen to a disc fitted to an STI, i belive it was on the track though.

[Lonx]

Any updates on the cause?

[Euroboost]

That does it, I'm not buying a D40! I'll get a Triton instead.

The only time I've heard something like this is when the rotor has been machined/worn below minimum thickness, not an issue here naturally.

[rowdytoot]

Euroboost- meh, i'm the only one to manage it :D

Comp Friction replaced both discs for free no questions asked...
DBA are apparently still 'investigating'. I've done maybe 500 km on the new discs so far, and they are all good..