Performs a pressure test on the cooling system to identify leaks in hoses, gaskets, radiator, water pump, or other cooling system components.

Warnings

Tools required

Parts

• Radiator cap (if worn or damaged) × 1 — Use OEM specification

Fluids

• Hyundai/Kia Long Life Coolant (Green) — 7.5 qt

Preparation

1. Ensure engine is completely cold to the touch before beginning work
2. Park vehicle on level surface and engage parking brake
3. Open hood and visually inspect cooling system for obvious leaks, damage, or loose hoses
4. Verify radiator cap pressure rating (should be marked on cap as 16-18 PSI)
5. Have replacement coolant available in case system needs to be drained or topped off

Procedure

1. 1

   Remove radiator cap and inspect
   Slowly turn the radiator cap counterclockwise to release any residual pressure, then remove completely. Inspect the cap gaskets for cracks, tears, or hardening. Check the pressure relief spring for proper tension. Replace cap if gaskets are damaged or spring is weak.
2. 2

   Check coolant level and condition
   Look into the radiator filler neck and verify coolant is visible at the top. If low, add Hyundai/Kia Long Life Coolant (Green) until full. Inspect coolant condition - should be green and translucent, not brown, rusty, or contaminated with oil. Check overflow reservoir level as well; should be between MIN and MAX marks when cold.
3. 3

   Install pressure tester adapter
   Select the correct adapter for the Forte radiator neck from your pressure tester kit. Install the adapter onto the radiator filler neck, ensuring it seats fully and creates a complete seal. The adapter should fit snugly without rocking or gaps.
4. 4

   Attach pressure tester and pressurize system
   Connect the pressure tester pump to the installed adapter. Slowly pump the tester to bring the system pressure up to the radiator cap rating (16-18 PSI). Do not exceed 20 PSI maximum. Watch the pressure gauge - it should hold steady once you stop pumping.
5. 5

   Monitor pressure gauge for leaks
   Observe the pressure gauge for 10-15 minutes. A properly sealed system should hold pressure with minimal drop (less than 2 PSI over 15 minutes is acceptable). A rapid pressure drop indicates a leak. Note the rate of pressure loss if applicable.
6. 6

   Perform visual inspection of all cooling system components
   While system is pressurized, thoroughly inspect all cooling system components for leaks. Check radiator tanks and core, upper and lower radiator hoses, heater hoses, thermostat housing, water pump (look for weep hole at bottom), coolant reservoir and hoses, and all hose clamps. Use flashlight and inspection mirror to check hidden areas behind engine. Look for dripping, seepage, or wet spots.
7. 7

   Inspect engine block and cylinder head
   Examine the engine block and cylinder head mating surface for coolant seepage indicating head gasket issues. Check freeze plugs on both sides of engine block for wetness or corrosion. Inspect around the thermostat housing bolts and water outlet connections.
8. 8

   Check heater core for leaks
   Inspect firewall area where heater hoses enter cabin for wetness. Check passenger side floor carpet or floor mat for dampness or coolant smell which would indicate heater core leakage. Note that heater core leaks may only be visible inside the vehicle.
9. 9

   Release pressure and remove tester
   Slowly open the pressure release valve on the tester to depressurize the cooling system completely. Once pressure reads zero, disconnect the pressure tester from the adapter, then remove the adapter from the radiator neck. Wipe any spilled coolant with shop towels.
10. 10

    Perform cap pressure test
    If your pressure tester has a radiator cap testing adapter, test the radiator cap separately. Attach cap to the tester and pump to specified pressure (16-18 PSI). The cap should hold pressure until the relief point, then release pressure smoothly. Replace cap if it fails to hold or release at proper pressure.

Reassembly

1. Install radiator cap by aligning tabs and turning clockwise until it clicks into locked position
2. Top off coolant reservoir to MAX line with Hyundai/Kia Long Life Coolant if needed
3. Wipe down any areas where coolant may have dripped during testing
4. If leaks were found and repairs made, retest cooling system following same procedure

Verification

• Confirm radiator cap is properly installed and locked in place
• Start engine and allow to warm up to operating temperature while monitoring for leaks
• Check that coolant level remains stable in reservoir during warm-up
• Verify heater produces hot air indicating proper coolant circulation
• After engine reaches operating temperature, shut off and allow to cool, then recheck coolant level - top off if necessary
• If pressure test revealed no leaks and system holds 16-18 PSI for 15 minutes, cooling system is sealed properly

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