Flushing

Flushing

Radiator Restrictions
A dirty, obstructed, or leaking radiator core causes overheating. Scale deposits result from using hard (high-mineral) water in the cooling system. Heating these minerals causes the formation of a hard coating on the surfaces within the radiator. Scaling reduces the transfer of heat. Some hard water produces a silt-like deposit that restricts the flow of water. A radiator that is partially restricted should be removed and cleaned by a radiator repair specialist. Replace a radiator core that is plugged or has a heavy scale.

Flushing Procedure

Important:
^ Remove the coolant thermostat before flushing the cooling system.
^ Dispose of the used engine coolant properly.
- Store the used engine coolant in a used coolant holding tank, while awaiting approved disposal methods.
- Do not pour used engine coolant down the drain.
^ Dex-Cool antifreeze is a very toxic chemical.
^ Disposal into a sewer system or contaminating the ground water is both environmentally irresponsible and illegal.
There are different methods to flush the cooling system. Back flushing is recommended. Special equipment is available. Follow the equipment manufacturer's instructions for use.

Radiator Cleaning Radiator Maintenance
Inspect the radiator for bent fins or signs of leakage. Repair or replace leaking radiator cores. Do not seal temporarily with a sealer type antifreeze or coolant additive. Remove any stones from between the fins. Clean loose debris from the radiator core. To maintain efficient heat dissipation, an occasional external flushing with water removes the majority of the dirt accumulation. Direct a stream of moderate water pressure from behind the radiator core to force debris out in the opposite direction of entry. Direct the water stream in line with the fins to reduce the possibility of bending the fins. Clean the road film from the radiator core with a quality grease solvent. Blow the solvent with compressed air from the rear to the front of the radiator core for more efficient cleaning. To ensure a thorough cleaning remove the grille and the fan shroud.

Inspection Procedure
1. Remove the radiator cap.
2. Look for plugged tubes. Look for scale on the inside of the tank.
3. Replace a badly plugged radiator.
4. Inspect the coolant level. If the coolant level is low, add the recommended coolant and concentration.
5. Inspect the condition of the hoses.
^ Tighten, or replace the hose clamps where leakage is evident.
^ Replace cracked, stripped or corroded clamps.
^ Inspect the hoses for a spongy or cracked appearance.
^ Replace the deteriorated hoses.
6. Inspect the radiator core for leaks.
7. Inspect for dirt obstructing the air passages that reduces the transfer of heat.
8. Inspect the coolant recovery tank for leaks.
9. Inspect the radiator mounting.
^ Inspect the rubber bumpers.
^ Inspect that the radiator mounting bolts are secure.
^ Inspect the radiator supports.
^ Inspect the braces.
^ Inspect the tie rods.
^ Inspect the stabilizer rods.
^ Inspect the radiator core side flanges.
10. Inspect the cooling fan.
^ Inspect the fan blade-to-radiator core clearances.
^ Inspect the fan blade-to-fan shroud clearances.
^ Inspect that the fan attaching bolts are all in place.
^ Inspect the fan attaching bolts for proper torque.
^ Replace the fan if a blade is bent.
- The distance to the shroud from the fan blade should be equal around the entire perimeter of the shroud.
- Correct as necessary after making any adjustment to the fan assembly, mounting bracket, or the water pump hub.
11. Inspect the radiator filler cap.
^ Inspect the seal for cracks.
^ Inspect the seal for signs of separation.