On the T3 throughout production there are 2 main types of two wheel drive (2WD) braking system, early and late, we won't confuse this page by including Syncro! (please see relevant Syncro section for Syncro brakes)
The early system ran from the start of production for the 1980 model year up until near the end of the 1986 model year and features fixed brake calipers with dual pistons.
The late system ran from just before the start of the 1987 model year up until the end of production in 1992 and feature a single piston floating caliper.
Both early and late systems could have been manufacturered by 2 different companies, ATE or Girling making 4 different sub systems.
Early ATE, Early Girling, Late ATE and Late Girling.
There doesn't appear to be any hard and fast rule to identify which manufacturer is used other than actually looking at the brake caliper.
Although the brake discs and brake pads don't change between the manufacturers the caliper and it's associated fittings do, if you need a brake caliper, brake pad shims etc then you need to pull a wheel off and identify which system you have.
If you aren't sure which system you have then please remove a wheel and take a picture and email it to us and we'll be happy to send you links back to the correct parts.
You can also use the "Early/Late" calculator found in the support section.