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Avo
14th July 2013, 05:22 PM
Guys I just noticed the front disc are starting to fracture.So looks like i'll be doing brakes next.So as there's a few sorts do I stick with the old style or go for drilled and grooved discs.Why do they fracture?
couldn't find no answers.

threedogs
14th July 2013, 05:26 PM
What year? are they OE disc.
DBA do a great Rotor just about to change myself to slotted and grooved but will see what others think first
maybe no good in mud and slop all the time.
Fractured disc unless its red hot and dunked in cold water I'm lost. but may have happened before.

is photo possible???

Parksy
14th July 2013, 05:47 PM
Sounds like they're getting too hot. Do you drive an auto? If not, the use of engine braking is a good way to help keep the disks cool. I've got rda dimpled and slotted rotors in mine. The drilled rotors are prone to cracking and filling up with mud.

threedogs
14th July 2013, 05:52 PM
Yeah heard that,
maybe just grooved
,worked ok on other 4x4 very well
or do they look cyrstalized

Avo
14th July 2013, 06:03 PM
tried to take a pic but cannot see them with ipod(camera spat it the other week)they are very fine cracks,but lots of them,
tr is 93 gq I presume there the old originals. and yep its an auto

pearcey
14th July 2013, 06:04 PM
Small cracks in disc`s is common especially if the brakes are abused.
Dont worry to much about it and if the disc are with in spec just re machine them.
All so aggressive pads can cause cracking and heat spots
New disc`s need to be bedded in properly as most are very green and will warp, get heat spots and give grief if not normalized correctly
The holes in the drilled discs give the disc a larger surface area for cooling and the slots are there to try and keep the pad surface clean.

Cuppa
14th July 2013, 06:05 PM
Could those who have changed from OE rotors & pads to aftermarket items comment on whether their braking performance improved & if so how & in what conditions.

Although the brakes on my heavy Patrol are adequate, they are certainly not confidence inspiring if needing to stop quickly from speed, & I have wondered if just changing rotors & pads on the front might give some worthwhile improvement.

Cuppa

pearcey
14th July 2013, 06:25 PM
Cuppa
Different material combinations give different performance also different brand combinations
It`s all experimentation,I have allways run genuine disc`s and Bendix pads.
Heat is your enemy but it can be used to your advantage if you know what temps you run at, then find a pad ,disc combo to suit.
This is all race teck, but with an infra red thermometer you can get some idea of where your at.

threedogs
14th July 2013, 06:31 PM
@ Cuppa Ron Moon has an extended GU dual cab and last I heard he was running BDA brakes with Kevlar pads
I can find out more on Monday if you like as his Patrol is quite weighty.
I had slotted only in the Troopy , they improved my braking heaps. If you have concerns ring Hopper Stoppers
in Hoppers crossing they can get anything to stop on a sixpence

lhurley
14th July 2013, 06:37 PM
I feel like my troll pulls up quite well since changing my discs and pads. I have dba rotors and qfm pads. Biggest improvement I made was rebuilding the brake calipers. It's really easy, and made a massive difference to my stopping ability

threedogs
14th July 2013, 06:41 PM
Mine needs an upgrade I'll talk to someone in the know next week ,to see what they say.
Save these rotors an machine so no down time, next pad change

Cuppa
14th July 2013, 06:47 PM
Cuppa
Different material combinations give different performance also different brand combinations
It`s all experimentation,I have allways run genuine disc`s and Bendix pads.
Heat is your enemy but it can be used to your advantage if you know what temps you run at, then find a pad ,disc combo to suit.
This is all race teck, but with an infra red thermometer you can get some idea of where your at.

I guess it's all compromise. I recall fitting 'green' Ferodo racing linings to a Triumph motorcycle twin leader front brake. Fantastic braking performance once hot, but useless when cold. Finding something which provides good all round performance is more difficult. I have an infrared thermometer but not the knowhow to use it's results. Can you but pads for specific temperature ranges?

Cuppa

pearcey
14th July 2013, 08:53 PM
I guess it's all compromise. I recall fitting 'green' Ferodo racing linings to a Triumph motorcycle twin leader front brake. Fantastic braking performance once hot, but useless when cold. Finding something which provides good all round performance is more difficult. I have an infrared thermometer but not the knowhow to use it's results. Can you but pads for specific temperature ranges?

Cuppa
When you know your temp range and the type of disc your running, IE type of material the disc is made from it`s just a matter of contacting a pad maker and talk to them. There are a lot more material compounds than just the commercial ones. Bendix head office is in Ballarat and you can talk to their Technical dept

Cuppa
14th July 2013, 08:59 PM
When you know your temp range and the type of disc your running, IE type of material the disc is made from it`s just a matter of contacting a pad maker and talk to them. There are a lot more material compounds than just the commercial ones. Bendix head office is in Ballarat and you can talk to their Technical dept

OK, a dumb question............... how best to measure the temp of the discs? They are not exactly accessible to point the thermometer at, & removing a wheel to do so is not very practical.

Cuppa

paulyg
14th July 2013, 09:09 PM
I replaced the rears with rda rotors and Bendix 4x4 pads, about 10000 km ago and so far very happy.

pearcey
14th July 2013, 09:21 PM
Cuppa are you still running split rims I can`t remember.
Could be difficult unless your running alloys or sunraisers
Possibly borrow a couple of wheels,but then there is the problem of different heat dissipation
It`s not a race car so 20 Deg is not going to make that much difference.

Cuppa
14th July 2013, 09:28 PM
Have the new Black Trak ROH steelies on now - didn't think of that, guess I can aim through the holes. :)

pearcey
14th July 2013, 09:35 PM
Done deal mate
There are a couple of pad manufacturers in Australia so an e mail or two and see what transpires
All have tech dept.

Avo
14th July 2013, 10:20 PM
Could those who have changed from OE rotors & pads to aftermarket items comment on whether their braking performance improved & if so how & in what conditions.

Although the brakes on my heavy Patrol are adequate, they are certainly not confidence inspiring if needing to stop quickly from speed, & I have wondered if just changing rotors & pads on the front might give some worthwhile improvement.

Cuppa

I feel the same,i often travel big km and always heading north where it is hot most days with my gq,and at times I have had to hit the brakes I wish they could stop a little better.I'll look at the calipers too I thinks.

Fox7
8th May 2015, 05:18 AM
Guys I just noticed the front disc are starting to fracture.So looks like i'll be doing brakes next.So as there's a few sorts do I stick with the old style or go for drilled and grooved discs.Why do they fracture?
couldn't find no answers.

I had similar experience, GQ front discs have small cracks. I guess reason would be heavy braking. Gonna replace both discs with OEM discs.