Fig. 804 Replacing The U4840 Coolant Pump; Fig. 805 Removing Overheating Protection Sensor - Webasto Thermo Pro 90 Series Service Installations

8 Repairing and replacing components
8.6 U4840 coolant pump

Fig. 804 Replacing the U4840 coolant pump

Removal
1. Remove heater (see section 7.5).
2. Disconnect plug connections (see section 8.4).
3. Undo screws (2x).
4. Remove clip and coolant pump.
5. Complete work on stripped down components (see sec-
tion 8.3).
Installation
1. Lubricate seal (between coolant pump and heat
exchanger) with acid-free grease (Vaseline).
2. Place coolant pump in assembly position and secure with
clip and screws.
3. Tighten screws (2x) to 3 Nm ± 10%.
4. Plug in connector at control unit (see section 8.4).
803
8.7 Overheating protection

Fig. 805 Removing overheating protection sensor

Removal
• The overheating protection should only be removed
when it is to be renewed.
• It must be checked in installed state.
1. Remove heater (see section 7.5)
(depending on space requirements).
2. Unplug electrical connections (see section 8.4).
3. Remove clip and detach protective cap.
4. Lever off retaining spring with a screwdriver and remove
overheating protection.
5. Complete work on stripped down components (see sec-
tion 8.3).
Installation
ATTENTION
Incorrect installation can cause the heat exchanger to burn
through.
1. Fit new overheating protection in heat exchanger and
press in retaining spring.
The spring must be heard and felt to snap into the
groove.
This ensures that the overheating protection is installed
in the correct position.
If the spring cannot be heard and felt to snap in:
• Clean contact surface of overheating protection on
the heat exchanger
• Clean the groove in the heat exchanger
• Make sure that there are locking lugs on both sides
of the spring. Replace overheating protection if
necessary.
2. Fit protective cap and secure with clip.
3. Tighten clip to 0.5 Nm ± 20%.
4. Plug in connector at control unit (see section 8.4).
5. If removed, install heater (see section 7.5).
Thermo Pro 90
NOTE
NOTE