I always thought that the caliper change occurred at the same time as the ADR31 brake upgrades around March '77. At that time they enlarged the master cylinder, added the BRAKE FAIL light & the 2-pin switch to operate it & also changed the routing of the front brake pipes & hoses.
This coincided with the change to the CLX chassis number prefix.
Dr Terry
I did find the ADR 31 note & part number change in the Torana Parts Illustration book but it was unclear to me what the ADR 31 change actually is.
My two SS hatch Compliance plates don't have ADR 31.
6/76 ALX... build has the early cast iron calipers & the hard brake line tubes terminating at the inner wheel well hole (with spring clip) & flexi lines other side.
9/76 BLX... car has the provision for the alternative hard brake lines. They goes through the inner guard hole (with rubber grommet) & ends at the angle bracket spot welded to the chassis rail under. Similar to A9X design. The front end has been re-bushed at some stage with an additional later dated steering rack (2/9/77).
The front end K frame has the lower UCA holes (60-65mm down from chassis mount plate & pre ADR 31 stub axles (different part #) & LX steering arms.
Both cars have the V8 double diaphragm booster, remote proportion valve, cast alloy master cylinder etc.
They both have the early type single wire brake fail warning light system.
So the only real differences between the 2 cars are the caliper types & front brake hard/flex line design.
Dr Terry, What you say make sense to me but I'm thinking there may have been a more progressive assembly line changes with redesigned parts upon supplier availability.
Does that make sense too?
Edited by Ando, 17 March 2018 - 08:45 AM.