Hudson 1938 Terraplane, Owner'S Manual

Page: 52 / 82

50 H U D S O N T E R R A P L A N E
When the water in the cooling system is cold, the thermostat located in the
cylinder head outlet causes the water to flow through the by-pass directly to the
pump inlet and back through the cylinder block. Therefore, during the warm-up
period, water does not circulate through the radiator.
However, as the water temperature increases and has reached 150° Fahrenheit,
the thermostat begins to open and gradually blocks oft the by-pass. The thermo-
stat is fully opened at 185° and the circulation is then through the radiator.
A special thermostat is available and may be installed in the water outlet
of De luxe models should temperature control be desired.
Water Pump
The water pump is of the vane type, located on the front of the cylinder block
and driven by the "V" belt, which also drives the generator.
An improved type packing gland of the permanent type is incorporated in the
pump and requires no adjustment.
It is essential that the fan belt be adjusted only to the specified tension as
outlined under "Generator" on page 45.
Draining the Cooling System
To drain the cooling system completely, open the draincock at the bottom of
the radiator (left side under hood), and also remove the pipe plug from the
cylinder block (left side to rear of side cover plate).
Care of the Cooling System
To maintain proper cooling efficiency, it is essential that the radiator be kept
clean of scale and corrosion, due to electrolytic action of water-containing
minerals and also deposits of minerals when the water is heated.
Unless special steps are taken to prevent these deposits, the cooling system
should be cleaned twice a year. This cleaning is most effective when the reverse
flushing method is used to remove deposits after they have been loosened by the
use of Hudson Radiator Cleaner. Reverse flushing requires the use of special
equipment operated by compressed air, and you should have this done by your
Hudson dealer.
To clean the radiator, run the engine a few minutes to circulate the water and
stir up loose sediment. Stop the engine and drain all water from the system.
Dissolve the contents of a container of Hudson Radiator Cleaner in a bucket
of hot water (be sure the material is completely dissolved). Pour the solution
into the radiator, then fill the radiator almost full of water.
Install filler cap tightly, cover the radiator and run engine for about twenty
minutes, but avoid boiling. Stop the engine and completely drain the system.
Reverse flushing will remove all the sediment the solution has loosened.
It is important that all traces of the cleaning solution be removed, as they will
have a detrimental effect if left in the system.