Outer Limits 4x4 Board

hey guys im going to be replacing discs and pads on front and back of the gq soon and was wondering what the best option would be either geniune, standard aftermarket or a good set of aftermarket maybe cross drilled or slotted style. thanks

It depends on the driving that you do. Just remember that you have a very heavy car so cross drilled is not recommended as the disc will warp much easier, especially if you go in and out of water. Slotted are usually the disc of choice for heavy offroad work but standard discs will do quite well if you use decent pads. A few questions for you?

1. What brakes do you have on your GQ now? Single or twin pot calipers?

2. What sort of driving do you do? Fast off/on road or normal daily driving?

3. Is cost a factor or are you happy to spend the extra $$$ if its worth it?

If you have single piston calipers for the front then that is the first thing to change. If you have twin piston calipers from a later model then standard discs with decent pads will cover most stuff. (I and many others race with this setup). If you still want better brakes then slotted discs are the go but steer away from cross drilled as they are prone to warping and cracking as well as getting crud stuck in the holes.

Cheers
Steve

im not sure what calipers are on it but i presume it has single pot calipers being an 89 model i think i will go with standard brakes and good pads and see how that goes then upgrade to twin pot calipers if needed, thanks

Twin pot claipers are a straight bolt on conversion that you can get from most 4x4 wreckers for a decent price. A very good and very simple break upgrade if you want it to stop a little better.

is there any need to upgrade the master cylinder or anything? or will they work properly as is

They will work fine. Your pedal may feel a bit harder to press so if this happens then go for a larger brake master cylinder.

no worries thanks alot

deano86 wrote:is there any need to upgrade the master cylinder or anything? or will they work properly as is

I think I read on here about someone putting a GU booster in their GQ and getting great results.

Not a simple bolt in, just some re-routing of the metal lines or something like that.

The twin pots are getting thin on the ground ! (up here anyways) last stock sold for $250 each

I ended up putting kits thru all calipers, new pads and rotors. I now have much better brakes than before.

(My rear pads were hardly worn, possibly partially seized slides on calipers. I can't remember when I put them in it would be at least 6-8 yrs?? )


cheers

What models came out with twins? Or are they aftermarket units.

Bigred Gq wrote:What models came out with twins? Or are they aftermarket units.

IIRC, the injected TB42 Models have the larger twin pot units.

cheers

The later EFI models have them but I'm not sure when they came in.

would you need a mod plate in QLD upgrading to a dual pot caliper?

Any guidelines on what to pay for 2 calipers from a wrecker?

You can expect to pay up to $250 each caliper from a wreckers. I don't think the DX models had twin pot calipers but I'm not sure. I've got a GU diff under mine so it has the GU brakes.

foodie wrote:would you need a mod plate in QLD upgrading to a dual pot caliper?

Any guidelines on what to pay for 2 calipers from a wrecker?

Seeing how you are putting another factory caliper on, I don't think it would require a mod plate YMMV

talk to the required people if you want to get technical about it!

cheers

Putting Twin piston brakes on isn't quite a bolt on job, it is and it isn't

You will need the following

1) Pair of Twin Piston GQ Callipers off a 92 onwards EFI model GQ
2) Pair of Rotors to fit Twin Piston GQ Patrol (Single piston ones are smaller)
3) Twin Piston brake pads (DB12574WD)
4) Master Cylinder upgrade

i did mine and when i used the single piston master Cylinder the brakes didn't work properlly they wouldn't pull the car up properlly cause it couldn't produce enough pressure. You have 2 options for this.
1) You can get a Master Cylinder off a Twin Piston GQ which bolts straight up to the original booster.
2) You can go GU Master cylinder however this requires you to get a GU booster as the GU master Cylinder uses 4 bolts to hold the master cylinder on, the GQ uses 2, they don't line up. Putting it in is the easy bit, getting the piping to work is the hard part. You need to swap the pipes around off the master Cylinder down the the distribution block on the chassis, this is a pain in the ass as its all metal lines and can cause a bit of a hard time to get it in

wat bout sloted roters ? how much ? and how well do they brake beta then single piston ones

gqmudder91 wrote:wat bout sloted roters ? how much ? and how well do they brake beta then single piston ones

Rotors and calipers are different things.

Slotted rotors wipe away the crap as well as provide better cooling therefore better braking.

Twin piston calipers are better than single piston calipers because you have more surface area for breaking so it provides more force on the brake rotor. But this then means more force required on the brake pedal unless you upgrade to a larger brake master cylinder.

MyGQ wrote: 2) You can go GU Master cylinder however this requires you to get a GU booster as the GU master Cylinder uses 4 bolts to hold the master cylinder on, the GQ uses 2, they don't line up. Putting it in is the easy bit, getting the piping to work is the hard part. You need to swap the pipes around off the master Cylinder down the the distribution block on the chassis, this is a pain in the ass as its all metal lines and can cause a bit of a hard time to get it in

Can you elaborate on that My GQ pls? So somewhere along the chassis is a distribution block with 2 pipes? and you swap the ends around?
Can you not just swap the 2 pipes at the master cylinder end? Cheers.

twodiffs wrote:

MyGQ wrote: 2) You can go GU Master cylinder however this requires you to get a GU booster as the GU master Cylinder uses 4 bolts to hold the master cylinder on, the GQ uses 2, they don't line up. Putting it in is the easy bit, getting the piping to work is the hard part. You need to swap the pipes around off the master Cylinder down the the distribution block on the chassis, this is a pain in the ass as its all metal lines and can cause a bit of a hard time to get it in

Can you elaborate on that My GQ pls? So somewhere along the chassis is a distribution block with 2 pipes? and you swap the ends around?
Can you not just swap the 2 pipes at the master cylinder end? Cheers.

Ok i will do my best. trying to swap the pipes over at the master cylinder good luck its near impossible unless you get new pipes made.

inside the drivers front guard just behind the shock tower there is a plate, remove this and you will see a block that has 5 pipes. there are 2 coming from the master cylinder at the top of it. On the back there is a a pipe that goes down to the front brakes. on the side there are 2 pipes that go to the rear brakes, one of them is run of the same circuit that runs the front brakes and another runs the secondary circuit that if the primary circuit fails the brakes still can stop.

you need to swap the pipes coming in at the top of the block from the master cylinder at the block itself.

I have been through this and by luck I didn't choose the 2 pot mod to fix my crappy GQs braking ability, for a while there i was convinced i had no choice but to go twin, I was wrong!

Don't bother with the 2 pot brakes, single pot GQ brakes work perfectly well if they are well setup and to spec...not many are.

Of coarse if a person wants 120k$ BMW braking ability then buy a BMW, my GQ brakes better than the 02 lancer and of coarse not better than the 2010 lancer (abs) but gee not that much far worse.

No fade whatsoever from legal speeds, of coarse if it was doing 160km/h the larger brakes will come into their own but we do not. It even pulls my 1.5tonne boat up from 100km/h without any fade so far and a couple of those stops have needed to be pretty damn fast from high speed.

IMO Get those brakes fixed for 10% the cost of a twin pot upgrade and just be happy.

car to elaborate on what you did to the single piston brakes?

hokey wrote:car to elaborate on what you did to the single piston brakes?

Sounds so silly as it costs stuff all so it couldn't be right but seriously all I did was fully change the fluid add 4x4 brake pads and adjust the bias valve to somewhere that works well, the calliper pistons where in fine shape.

The mechanic who did my initial roadworthy and it passed easily the braking bit told me that this one was just the way GQ brakes are, 2 clutch and brake specialists also said pretty much the same after taking it for a drive, all recommended slotted disks or at least 4x4 pads all round to make it a bit better.

I worked out that the secret is to get all of the air out when bleeding...this took literally litres of fluid to accomplish and a very pissed off wife (Pedal pusher) by the end of it, I have done all my cars since forever + many others and the GQ is without doubt the mega hardest to get right....and seriously of the 6 or so other GQs i have driven none where bled properly. I now need to be extra careful in the wet when driving this car as i can howl the tyres without that much effort especially at slow speeds like 60km/h.

Pedal is rock hard under all braking, and under all but the more panicked pull ups my big toe can handle the peddle pressure needed, next is the bias valve (actually the load compensating valve)needs be properly adjusted and deliberately bled along with the rest of the system.

Mine is 4 wheel disk but I also worked on my mates rear drum GQ and it also pulled up pretty well once we got everything standard all sorted proper, he did not think there was anything wrong either....and that's the trap...sounds like a story but it just isn't.

fnqcairns wrote:

hokey wrote:car to elaborate on what you did to the single piston brakes?

Sounds so silly as it costs stuff all so it couldn't be right but seriously all I did was fully change the fluid add 4x4 brake pads and adjust the bias valve to somewhere that works well, the calliper pistons where in fine shape.

The mechanic who did my initial roadworthy and it passed easily the braking bit told me that this one was just the way GQ brakes are, 2 clutch and brake specialists also said pretty much the same after taking it for a drive, all recommended slotted disks or at least 4x4 pads all round to make it a bit better.

I worked out that the secret is to get all of the air out when bleeding...this took literally litres of fluid to accomplish and a very pissed off wife (Pedal pusher) by the end of it, I have done all my cars since forever + many others and the GQ is without doubt the mega hardest to get right....and seriously of the 6 or so other GQs i have driven none where bled properly. I now need to be extra careful in the wet when driving this car as i can howl the tyres without that much effort especially at slow speeds like 60km/h.

Pedal is rock hard under all braking, and under all but the more panicked pull ups my big toe can handle the peddle pressure needed, next is the bias valve (actually the load compensating valve)needs be properly adjusted and deliberately bled along with the rest of the system.

Mine is 4 wheel disk but I also worked on my mates rear drum GQ and it also pulled up pretty well once we got everything standard all sorted proper, he did not think there was anything wrong either....and that's the trap...sounds like a story but it just isn't.

I hope the ''liters of fluid'' was beer

is the bias valve/load compensating valve the one on the rear diff? i can hardly ever get my rear brakes to lock up and i think it's because of that. wonder how it would go if i removed it?

Nope LOL! not litres of that type of fluid but over the 2 days of doing more bleeding/adjusting and swearing, then the 10 k round trip drive to my quiet braking test track something like 10 times (the GQ takes a fair stretch to get to 80-100km/h ) if I ever need to do this again I will get drunk and someone else can drive.

yeah in the end I used over 3 liters of fluid, any air in there and the pedal softens and the bloody car just starts to coast half way through a hard stop...feels like it fades but the issue is not heat at the pads but air still in the system, it's a right bitch to bleed but when it's all gone from everywhere the pedal stays 2x harder under full emergency braking.

hokey yes that's the one, don't take it away, when I finally got mine adjusted proper I got an extra 15% or more brakes unloaded, most noticeable under everyday traffic stops....they are as easy as now but it has gotta make a difference everywhere else too.

I forget which way I adjusted the arm and then the spring loop it's been 4 years now, think I shortened them, still you will work it out on your test drives it can make quite a dramatic change, that mess of brake tube up there hides air that a normal bleed does not fully remove...i remember this quite well.

Good luck!

Thanks MyGQ...thats a good easy to understand description of what to do.

very helpful thread. i'll pm the moderator about adding it to the bible

fnqcairns wrote:Nope LOL! not litres of that type of fluid but over the 2 days of doing more bleeding/adjusting and swearing, then the 10 k round trip drive to my quiet braking test track something like 10 times (the GQ takes a fair stretch to get to 80-100km/h ) if I ever need to do this again I will get drunk and someone else can drive.

yeah in the end I used over 3 liters of fluid, any air in there and the pedal softens and the bloody car just starts to coast half way through a hard stop...feels like it fades but the issue is not heat at the pads but air still in the system, it's a right bitch to bleed but when it's all gone from everywhere the pedal stays 2x harder under full emergency braking.

hokey yes that's the one, don't take it away, when I finally got mine adjusted proper I got an extra 15% or more brakes unloaded, most noticeable under everyday traffic stops....they are as easy as now but it has gotta make a difference everywhere else too.

I forget which way I adjusted the arm and then the spring loop it's been 4 years now, think I shortened them, still you will work it out on your test drives it can make quite a dramatic change, that mess of brake tube up there hides air that a normal bleed does not fully remove...i remember this quite well.

Good luck!

what order did u bleed compnents in? how do u bleed it 'propely''?

good info.