128
Cooling system – description
The function of the cooling system is to cool the en-
gine, and if the bus has a separate hydraulic retarder or
retarder built into the gearbox, also the oil for the re-
tarder or gearbox. The engine gets its cooling from
coolant pumped round the engine in the coolant drill-
ings and by the coolant also flowing through the oil
cooler, this contributing to engine cooling by lowering
Layout diagram, cooling system
7
6
1
8
10
11
18
9
13
12
4
5
15
max.
min.
3
2
14
19
16
17
1. Expansion tank
2. Radiator for intercooler 2
3. Radiator for engine circuit and intercooler
circuit 1
4. From bus interior radiators
5. From windscreen defroster and possibly
heated lube oil tank
6. To windscreen defroster and possibly
heated lube oil tank
7. To bus interior radiators
8. Thermostat, interior heaters
9. Thermostat for regulating fan speed
10. Thermostats, engine
11. Pressure retaining valve
12. Coolant pump, engine circuit and intercoo-
ler circuit 1
13. Coolant pump, intercooler circuit 2
14. Oil cooler, engine
15. Engine
16. Intercooler element 2
17. Intercooler element 1
18. Thermostat, intercooler circuit 1
19. Oil cooler in gearbox/retarder
The engine and intercooler circuits are connected up as
before. The cooling circuit for the hydraulic retarder
and the automatic transmission are coupled in series
with the engine cooling circuit. If the bus does not have
an hydraulic retarder or automatic transmission (pos.
19), their connections on the thermostat housing are
inter-coupled with a pipe elbow and the thermostat
housing has only one vent hose.
Pos. 9 is the thermostat valve that controls the hydrau-
lic pump and thereby the fan speed. (Hydraulic-driven
fan.)
the engine oil temperature. Two piston type main ther-
emostats regulate the engine coolant temperature. The
system also has two other thermostats: a heating sys-
tem thermostat and a thermostat for the retarder (or
gearbox) oil cooler. The thermostats direct the coolant
flow to the respective circuit to the extent they are in-
fluenced by the coolant temperature.
Содержание DH10A 245
Страница 1: ...Service Manual Buses Section 2 20 27 Engine DH10A 245 285 345 350 360 TP 16031 1 ...
Страница 31: ...30 Adjust in the supports on the lift unit as shown in the pictures below ...
Страница 59: ...58 Cylinder block crank mechanism ...
Страница 162: ...Volvo Bus Corporation TP 16031 1 English 2500 06 97 Printed in Sweden by Novum Grafiska AB 97 24296 Göteborg Sweden ...