➤ The coolant should be mixed in the proportions stated by the manufacturer.
Coolant mixture table:
Percentages [% vol.]
Frost protection up to approx. [°F]
Corrosion inhibitor/anti‐
freeze
Water
50
50
−35
Tab. 86 Coolant mixture table
Do not use a higher concentration than 55% vol. of corrosion inhibitor/antifreeze even in ex‐
tremely low ambient temperatures. The maximum frost protection is reached with 55% of cor‐
rosion inhibitor/antifreeze. This corresponds to frost protection to approx. –49°F.
The concentration of antifreeze should not be less than 33% since corrosion protection can
no longer be guaranteed and heat transfer properties deteriorate beyond this point!
10.3.1.4 Filling and topping off the coolant
The proportion of antifreeze in the coolant should not fall below 33% to ensure optimal frost and
corrosion protection and prevent the build-up of deposits (sludge) in the cooling circuit. Topping off
with water alone dilutes the antifreeze concentration and is therefore forbidden.
Make sure that there is sufficient room for hot coolant to expand without overflowing.
Precondition The negative cable to the battery is disconnected.
1. Loosen and remove the coolant expansion tank filler cap.
2. Mix a quantity of coolant according to the table and replenish to the mark.
Replenish the coolant to just below the
maximum mark
A
.
3. Screw on the filler cap.
4. Reconnect the negative cable to the battery.
5. Close the canopy.
6. Start the drive engine and allow to IDLE for about 1 minute.
7. Stop the drive engine.
8. Open the canopy.
9. Check the coolant level.
If the coolant level in the expansion tank has decreased: Top off the coolant.
10. Visually inspect for leaks.
11. Close the canopy.
10.3.1.5 Draining the coolant
Precondition The machine has cooled down.
The negative cable to the battery is disconnected.
Draining the coolant
The complete volume of coolant contained in the circuit can be drained at the drive engine's water
cooler. The water cooler is drained by a separate screw plug (accessible from underneath through
the access hole in the floor pan).
10 Maintenance
10.3 Drive engine maintenance
96
Operator Manual Screw Compressor
MOBILAIR M27
No.: 9_9547 13 USE
