TB5 - Technical Bulletin 5
Front Brake Calliper Options
Over the HQ-HZ series, several front brake calliper options were used, mainly in an effort to reduce unsprung weight. The original cast iron PBR callipers weigh 5 kg each.
Excluding the WB utes, the calliper styles and suppliers were as follows;
HQ - PBR cast iron
HJ - Girlock cast iron
HX - PBR alloy/cast iron
HZ - Girlock alloy/cast iron
There is nothing wrong with the cast iron items, and they are often the recommended choice because they don't flex, but for those wanting to reduce unsprung weight, the alloy/cast iron units offer a 1 kg lighter alternative.
The images below are of HX PBR alloy/cast iron callipers. They aren't the prettiest looking units available, the HZ Girlock alloy/cast iron, in our opinion look better.
If you do change callipers, even though the HQ flexible brake hoses will fit, at full suspension droop when jacking up the car, the hoses will be stretched. Replace with the items that match the callipers you are fitting.