A. Model 1 15.1 and 123.1 ( 1st version up to February 1979)
Removal
1. Drain coolant.
2. Disconnect hose on thermostat housing cover.
3. Unscrew thermostat housing cover.
4. Remove thermostat with seal out of cover.
Installation
5. When a riew thermostat is installed, place a new gasket on tnermostat housing.
6. Position thermostat with gasket in cover in such a manner that tne arrow on therrnostat is pointing up wards or toward the rear in installed coridition.
7. Screw-on cover and connect hose.
8. Add coolant (20-010).
9. Pressure- test cool~ng system WI th tester.
B. Model 123.1 (2nd version starting February 1979)
Removal
1. Drain coolant.
2. Disconnect hose on therrnostat housing cover.
3. Unscrew thermostat housing cover.
4. Remove thermostat with gasket out of cover.
5. When a new thermostat is installed, place a new gasket on thermostat housing.
6. Position thermostat with gasket in cover in such a manner that the arrow on thermostat i s pointing upwards or toward the rear in installed condition.
7. Screw-on cover and connect hose.
8. Add coolant (20-010).
9. Pressure-test cooling system with tester.
