Cooling System; General Description - Perkins New 1000 Series Workshop Manual

New 1000 Series
12

Cooling system

12

General description

Coolant from the bottom of the radiator passes through the centrifugal coolant pump, which is fitted onto the
front of the timing case to assist the flow of the coolant through the system.
The pump is normally gear driven from the gear of the fuel injection pump. On certain four cylinder applications
the pump is driven by a "V" belt from the crankshaft pulley. Some engines are fitted with a belt driven coolant
pump in a high position, these are identified by the thermostat housing which is part of the pump rear body.
The rear body of these pumps has a connection to a coolant transfer plate, which allows coolant from the pump
impeller to pass into the cylinder block.
Two types oil cooler are available for use on four cylinder engines: An integral oil cooler which is fitted to the
left side of the cylinder block or a separate (cassette type cooler) fitted to the filter head.
The integral oil cooler has an aluminium cover with plate element and is fitted to the left side of the cylinder
block.
The latest integral oil coolers for 6 cylinder engines have a pressed steel cover.
Four cylinder engines
From the pump, the coolant passes through a passage in the timing case to the water jacket in the left side of
the cylinder block. Coolant pumps driven by a "V" belt do not pass the coolant through a passage in the timing
case but direct to the front of the cylinder block. The coolant continues to the rear of the cylinder block where
some of the coolant passes into the lubricating oil cooler, if one is fitted. Some of the coolant passes around
the element of the integral cooler and then to the rear of the cylinder block.
Some four cylinder engines have a cassette type oil cooler fitted between the oil filter canister and the oil filter
head. If the cassette oil cooler is fitted on the left side of the engine, coolant from the by-pass connection at
the rear of the coolant pump passes through a pipe to the oil cooler. If the cassette oil cooler is fitted to the
right side of the engine, a pipe is connected between the thermostat housing and the oil cooler. The coolant
passes around the plates of the cooler and passes through a pipe to the cylinder block.
The coolant then passes from the rear of the cylinder block and into the cylinder head. The coolant leaves the
cylinder head at the front and passes into the thermostat housing.
If the thermostat is closed, the coolant goes directly through a by-pass to the inlet side of the coolant pump. If
the thermostat is open, the thermostat closes the by-pass and the coolant passes to the top of the radiator.
Some engines are fitted with two thermostats.
Six cylinder engines
On six cylinder engines the coolant divides as it enters the cylinder block. Most of the coolant passes along
the right hand side of the cylinder block and around the outside of the cylinders to the rear of the cylinder block.
The remainder of the coolant passes along a passage on the left hand side of the cylinder block to the
lubricating oil cooler.
The coolant flows around the element of the lubricating oil cooler to the rear of the cylinder block. The coolant
then passes to the rear of the cylinder head.
Coolant passes forward through the cylinder head and into the thermostat housing. These engines have one
thermostat. If the thermostat is closed, the coolant goes, through a by-pass, directly to the inlet side of the
coolant pump. If the thermostat is open, the coolant passes to the top of the radiator.
Some engines are fitted with two thermostats.
Workshop Manual, TPD 1350E, Issue 4 257
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