Maximum frost protection is ensured with an antifreeze concentration of 55% by volume, as frost
protection and heat transfer properties deteriorate beyond this point. Higher concentration also
leads to higher operating temperatures of the drive engine.
1.
The engine can be damaged if the antifreeze concentration is insufficient!
Corrosion.
Damage to the cooling system.
Engine casing fracture.
➤ Check coolant.
➤ Protect the coolant against frost.
➤ Immediately top off as necessary.
2. Use the coolant tester as instructed by the manufacturer to test the coolant.
Concentration of antifreeze is too low: Change the coolant.
Performing final work steps
1. Screw on the filler cap.
2. Close the canopy.
10.3.1.3 Mixing coolant
The coolant is a mixture of clean, fresh water and antifreeze with corrosion inhibitor.
For reasons of corrosion protection and the need to raise the boiling point, the coolant must remain
in the cooling system throughout the year.
The maximum permissible coolant life is 3 years.
Never use water without coolant additive. Water alone is corrosive at drive engine operating tem‐
perature. Water alone does not offer sufficient protection from boiling or freezing.
You will find an adhesive label with the recommended mixture ratio for the coolant close by to the
coolant expansion tank, see Figure 27.
Fig. 27 Recommended mixture ratio for coolant
1
Water
2
Corrosion inhibitor/antifreeze
➤ For recommended coolant, please adhere to the information regarding the initial filling, Chapter
Preparing coolant
Precondition Coolant meets the prescribed operating instructions of the engine manufacturer KUBOTA.
10 Maintenance
10.3 Drive engine maintenance
No.: 9_9547 13 USE
Operator Manual Screw Compressor
MOBILAIR M27
95
