Draining the coolant:
The full volume of coolant contained in the cooling circuit can be drained via the drive engine cool‐
ant cooler. The coolant cooler is equipped with a coolant drain valve. Coolant is easily and conven‐
iently drained away by screwing the male hose coupling onto the coolant drain valve.
Fig. 30 Draining the coolant
1
Coolant cooler
2
Drainage port
3
Coolant drain valve
4
Protective cap
1. Loosen and remove the filler cap on the coolant expansion tank.
2. Position the receptacle.
3. Loosen and remove the protective cap for the coolant drain valve.
4. Screw the male hose coupling onto the coolant drain valve.
5. Allow the coolant to drain out.
The coolant has drained completely.
6. Unscrew and remove the male hose coupling.
7. Screw the protective cap back onto the coolant drain valve.
➤ Dispose of used coolant in accordance with the applicable environmental protection regu‐
lations.
10.3.1.6 Removing scaling from inside the coolant cooler
After extended periods of use, scaling may form inside the cooling circuit, and the coolant cooler in
particular. The resulting reduced heat transfer can lead to the drive engine overheating.
NOTICE
Scaling in the cooling circuit
Damage caused by drive engine overheating.
➤ Use a cooler cleaning agent to remove scaling from inside the coolant cooler.
1. Read and observe the manufacturer’s instructions regarding the use of cooler cleaning agent.
2. Use a cooler cleaning agent to remove scaling from the coolant cooler.
Further information If the maintenance message “Change coolant” is displayed, use a cooler cleaning agent to remove
scaling from inside the coolant cooler, see chapter 10.2.3.1.
10 Maintenance
10.3 Drive engine maintenance
No.: 9_9548 22 HCE
Operating Manual Portable Rotary Screw Compressor
MOBILAIR M27 PE
105
