Upgrade GQ TB42S to GU brakes

[chris 89 GQ]

Hi Folks, I want to upgrade my GQ front brakes as part of an engineering approval for a NA Barra engine swap. I've seen quite a bit of discussion on GU front brakes being a straight swap with a couple of conditions like larger 17 inch rims and shorter calliper bolts required along with an upgraded brake booster. There seem to be a few GU style 3rd party upgrade kits available on the market but they can be very expensive ~$2,500 ... Can someone confirm that the GU front brakes are a bolt on? Can anyone suggest a more cost effective way to upgrade the front brakes and still achieve engineering approval. I live in NSW and the engineering folks here will likely insist on testing the brakes to make sure they comply with the standards required. Cheers, Chris

[geoffayres]

I believe the GU brakes do not bolt directly to the GQ.

You'll need to fit GU diffs to get GU brakes.

GU front brakes, even the bigger TB48's, are OK with 16" rims.

[mudnut]

@PeeBee. What did you upgrade your mighty V8 Patrol brakes with.

[PeeBee]

Chris, I have a GQ LWB that has undergone VASS Engineering in Vic successfully, including a GVM upgrade which required a brake test. Where I have landed is the end of a very expensive pathway, however I can tell you the steps and your solution could be quite cheap.

My vehicle is very heavy also, circa 3800- 3900kg

1) I passed my brake test, 22 emerg stops 60-0 and 22 emerg stops 80-0, consecutively, and I did this with the standard Nissan patrol single pot calipers on my 1997 wagon, standard pads and fitted with the braided brake lines. I firmly believe the braided lines were the success. The factory pads are sticky and full brake pressure without loss from the unbraided hoses.
2) I upgraded to the GQ twin pot calipers, with factory pads, and braided lines but did not find the performance as spectacular as I was led to believe it would be. I since gave this set up away to a mate with a GQ ute and he found the upgrade spectacular, but he is a lot lighter.
3) I upgraded to the full Willwood setup, 6 pot fronts and 4 pot rears with a fully rebuilt GU48 booster/master cylinder. The setup was less than spectacular, mostly I think because the Willwood pads are so hard and they need a lot of heat to get them hot.
4) I ditched the GU master and booster and upgraded to the Marks 4x4 Hydroboost. The brakes are firm and they will lock up the wheels in the dry without much effort - in fact the limiting factor is the rubber on the road. I have the set up I am happy with, but they work best in the dry with all terrains rather than mud terrains.

In summary, swap out your standard brake lines to braided and run factory pads and you should pass the test.

Thanks Craig, was typing when your prompt came thru!

Also, just remembered the Willwood discs are large and wont fit on rims less than 17" dia, so I upgraded to the GU Alloys, been happy with them so far. I still need to call Willwood distributor - Rod Shop in Bendigo Vic to see if there are softer equivalent pads to suit their calipers. If yes these brakes would be mint.