vw-2 bmw-a1 nat_auto woodford_ origo-2 finol autoparts-2 serfac270514a

Meyle’s five steps for a clean cooling system


Thorough and regular flushing is one of the decisive steps in the maintenance of cooling systems. Contamination, e. g. due to the incorrect use of sealing compound in the cooling system, reduces the cooling capacity in the long run and can lead to premature failure of the water pump mechanical seal.

But even beyond this, proper flushing of the cooling circuit is the basis for longer engine service life. This should take place at the latest when the water pump is replaced in order to remove particles that can be caused by corrosion or limestone.

The Hamburg-based manufacturer, Meyle now supports workshops with a special tool. With this tool, which Meyle offers in a joint cooperation with its partner Hazet, the cooling system can be cleaned with the aid of water and compressed air – completely without aggressive chemicals and cleaners. Meyle shows how the engine cooling circuit can be cleaned in five simple steps.

Step 1: Preparation
The engine must be completely cooled down before starting work. The old coolant is then drained and the coolant expansion tank cleaned or replaced if heavily soiled. For environmental reasons, it is important to dispose of the waste liquid properly.

Step 2: Flushing the cooler
Remove the upper and lower radiator hoses on the radiator. The lower radiator hose is thoroughly rinsed from bottom to top for about two minutes with the radiator cap closed using the Meyle tool. Short pulses of pulsating air into the system increase the effectiveness. The upper radiator hose can then be flushed from top to bottom until the outflowing water is clear and deposits have been removed.

Step 3: Flush engine block
Next, remove the radiator hoses. Using the Meyle cooling circuit flushing tool, the upper radiator hose is thoroughly flushed until the outflowing water remains clear and any deposits have been removed. Also in this step short pulsating air blows increase the effectiveness of the rinsing process.

Meyle workshop advice: If the thermostat blocks proper rinsing, it must be removed for rinsing. In this context, Meyle recommends a general replacement of the thermostat.

Step 4: Flush the heat exchanger
If possible, the circuit to the heat exchanger should also be flushed until the outflowing water is clear. As a general rule, flushing the radiator, engine block and heat exchanger removes deposits of corrosion, limestone and silicone seal residues from the cooling system. These can accumulate over many years and permanently impair the functionality of the system.

Step 5: Refill the system
In the final step, all hoses, the drain valve and the thermostat are reattached. It must be checked whether all necessary connections have been made again. The cooling system can then be refilled with the coolant specified by the manufacturer. The mixing ratio should, for example, be checked with a refractometer. Finally, the system should be properly vented. A final check ensures that there are no leaks.