Pressure-Testing Cooling System - Volvo DH10A 245 Service Manual

Pressure-testing cooling system

Special tools:
(999) 6662 Pressure tester
6049 Hose (with nipple)
6441 Test cap for expansion tank
with thread
Stage 1
From compressed-air workshop supply
Check the coolant hoses for ageing (hardness),
cracks, etc. Replace damaged or worn hoses before
checking for leakage. If necessary, top-up before
pressure testing.
Place or hang up the pressure tester gauge above the
radiator to prevent coolant from getting into it.
Slowly raise the pressure to above 40 kPa (0.4 kp/cm
to build up the pressure in the cooling system. At ap-
prox. 50 kPa (0.5 kp/cm
function should start to release the pressure. If the pres-
sure cap does not work in this way, renew it.
Lower the pressure in the system and disconnect the
pressure tester from the engine drain nipple.
2
), the pressure cap overflow
Temporarily connect the pressure tester along with the
test cap in place of the pressure cap. Test at a pressure
of 70 kPa (0.7 kp/cm
When pressure has stabilized, check all the compo-
nents in the system for leakage – radiator, connections,
hoses, coolant pump, heating system, etc. If the pres-
sure gauge indicates pressure drop, then there is leak-
age, which must be remedied without delay.
Stage 2
Level sensor
Because of the different types of impurities that can get
into the expansion tank, the level sensor should be tak-
en out and cleaned at least at the annual service.
Coolant
The mixture in the Volvo coolant should be between
40% and 60%. Less than 40% will not provide protec-
2 )
tion against rust, in some cases it may even increase.
WARNING! Coolant is poisonous.
Mix per cent for
protection against
frost down to
2
).
40% 45% 50%
–25°C –30°C –40°C
–13°F –23°F –40°F
60%
–56°C
–69°F
139