G'day Ben and :welcome: it sound like you might need to bleed the clutch for starters and see if that helps. To bleed the system you will find a soft rubber hose running from the valve just under the bonnet in front of the clutch m/cyl back down to the l/h side of the trans, you need to blank this off with a pr of vice grips and then with the engine running have someone pump the clutch a couple of times then while they hold it down you need to release the fluid. The bleeder on these is on the l/h side of the bellhousing in behind the cab mount and it looks like a hyd test port coupling, just get a small screwdriver and push the centre pin in. You will get oil spraying everywhere they are a fool of an idea:confused2:.
Good luck and let us know how you get on
Jon