Agricultural Equipment Technician (Red Seal)

Performs common occupational skills

A technician must top up engine coolant on a tractor. Which step occurs first?

1. Open the radiator cap while the engine is at operating temperature before any further work
2. Add tap water and check colour against the reservoir
3. Confirm coolant type and concentration meet the equipment specification
4. Run the engine at high idle and watch for bubbles in the reservoir

Coolant compatibility must be confirmed before any fluid enters the system because mixing organic acid, hybrid and inorganic coolants causes gelling, seal damage and corrosion that the technician cannot see until the next service interval. Opening a hot radiator cap releases pressurized scalding fluid and is a documented thermal-burn mechanism. Plain tap water introduces mineral scale that fouls the heat exchanger and degrades the additive package. Watching for bubbles at high idle is a head-gasket diagnostic, not a top-up procedure, and bypasses the fluid-compatibility check that protects the cooling system.

RSOS 2021 | A-2.02 Maintains fluids, lubricants and coolants

Diagnoses and repairs engines and engine support systems

A tractor cooling system loses coolant with no external leak visible. Which test should the technician perform first?

1. Replace the radiator cap and refill the system with new coolant
2. Block-test the coolant for combustion gases using a chemical indicator
3. Drain the engine oil and inspect the pan for water contamination
4. Run the engine at full load and watch the temperature gauge response across the equipment

A combustion-gas block test uses a chemical indicator drawn over the coolant; a colour change confirms exhaust gases are entering the coolant through a head-gasket or cracked-head path. Replacing the cap blindly addresses one possible leak point but skips the diagnosis. Inspecting the pan finds coolant in oil only after migration is already severe. Running at full load can accelerate the failure and risks warping the head before the cause has been confirmed at low risk.

RSOS 2021 | B-6.03 Diagnoses cooling systems

Diagnoses and repairs drive trains

What is required when installing a new dry clutch disc?

1. Apply chassis grease to both sides of the disc to prevent squeak
2. Hand tighten the pressure plate bolts and let the engine seat them carefully on the unit
3. Use the alignment tool and torque the pressure plate to the manufacturer specification
4. Heat the pressure plate before installation to ease alignment

An alignment tool centres the disc on the pilot bearing while the pressure plate bolts are torqued in sequence to the manufacturer specification; this ensures the input shaft engages on first installation. Grease on the friction surface causes immediate shudder and slip. Hand-tightened bolts allow the cover to walk under spring force and warp. Heating the pressure plate anneals the diaphragm spring and changes the clamping load.

RSOS 2021 | C-9.01 Repairs dry clutches