Lubrication - Isuzu L Series Manual

II. Engine Component Description

Lubrication

U
L-Series Diesel
Lubrication is achieved with a conventional
wet sump oiling system. Internally, the
trochoid oil pump uses a set of rotors instead
of spur gears.
It is a very efficient and smooth operating
pump. Compared with the spur gear type
pump, the trochoid pump gives practically
continuous flow, due to less leakage on the
discharge side of the pump.
The pump is mounted to the front of the
engine block and driven by the crankshaft.
On the pump's exterior housing, there are two
lugs machined for dowel pins. This enables the
pump to be repositioned in exactly the same
location without having to set pump gear
backlash.
The pump is a serviceable unit. Internal
components are interchangeable between PTO
and non-PTO versions.
TIP: Always remove the pump's pressure
relief valve during a rebuild. Look for a
cocked pressure spring, burred relief valve or
burred pump housing that would cause the
pressure valve to fail. (If housing is burred, it
must be replaced.)
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