Ford Mustang (1999-2004) Service Manual: Component Tests

Pressure Test

1. Turn the engine OFF.

2. WARNING: Never remove the pressure relief cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system, never remove the pressure relief cap from a hot degas bottle. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly one turn (counterclockwise). Step back while the pressure is released from the cooling system. When certain all the pressure has been released, remove the pressure relief cap (still with a cloth).

Check the intercooler coolant level. For additional information, refer to Supercharger Cooling System Draining, Filling and Bleeding in this section.

3. Connect the Radiator/Heater Core Pressure Tester to the degas bottle nipple. Install a pressure test pump to the quick-connect fitting of the test adapter.

4. NOTE: If the plunger of the pump is depressed too fast, an erroneous pressure reading will result.

Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.

5. If the pressure relief cap does not hold pressure, remove and wash the pressure relief cap in clean water to dislodge all foreign particles from the gaskets. Check the sealing surface in the filler neck.

6. If 69 kPa (10 psi) cannot be reached, install a new pressure relief cap. If more than 12 kPa (18 psi) shows on the gauge, install a new pressure relief cap.

7. CAUTION: If the pressure drops, check for leaks at the intercooler hoses or other system components and connections. Any leaks which are found must be corrected and the system rechecked.

NOTE: Intercooler system is not connected to the main engine cooling system.

Pressurize the intercooler cooling system as described in Step 4 (using a pressure relief cap that operates within the specified upper and lower pressure limits). Observe the gauge reading for approximately two minutes; refer to General Specifications. Pressure should not drop during this time.

• If the pressure drops and no external leak is found, the intercooler may be the cause.

  Remove and inspect the intercooler. Install a new intercooler if necessary.

8. Release the system pressure by loosening the pressure relief cap. Check the coolant level and replenish, if necessary, with the correct coolant mixture. For additional information, refer to Supercharger Cooling System Draining, Filling and Bleeding in this section.

Cap

WARNING: Never remove the pressure relief cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system, use extreme care when removing the pressure relief cap from a hot degas bottle. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly one turn (counterclockwise). Step back while the pressure is released from the cooling system. When certain all the pressure has been released, remove pressure relief cap (still with a cloth).

1. Immerse the pressure relief cap in water and install it on the shallow filler neck of Radiator/Heater Core Pressure Tester and Radiator Cap Adapter, part of Radiator/Heater Core Pressure Tester.

2. Immerse the filler neck seal in water and install it in the filler neck adapter.

3. Install the filler neck adapter with the filler neck seal to the Radiator Cap Adapter.

4. Connect the female quick-connect fitting of the pressure test pump to the male quick-connect fitting of the filler neck adapter.

5. NOTE: If the plunger of the pump is depressed too fast, an erroneous pressure reading will result.

Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.

6. Release the pressure by turning the relief screw counterclockwise. Then tighten the pressure relief screw and repeat Step 6 (at least twice) to make sure the reading is repeatable within the specifications of the pressure relief cap.

7. If the pressure test gauge readings are not within specifications, install a new pressure relief cap. If the pressure test gauge readings are within specifications, carry out the cooling system pressure test.

Radiator Leak Test, Removed From the Vehicle

CAUTION: Never leak test an aluminum radiator or intercooler in the same water that copper/brass radiators are tested in. Flux and caustic cleaners may be present in the cleaning tank and they will damage aluminum radiators and intercoolers.

NOTE: Clean the radiator or intercooler before leak testing to avoid contamination of tank.

1. Leak test the radiator or intercooler in clean water with 138 kPa (20 psi) air pressure.