Dodge RAM TRUCK 1500 1995 Service Manual page 943

OIL P O I P
OIL PUMP PRESSURE
The MINIMUM oil pump pressure is 41.4 kPa (6
psi) at curb idle. The MAXIMUM oil pump pressure
is 207-552 kPa (30-80 psi) at 8,000' RPM or more.
CAUTION: if oii pressure is Z E R O at curb idle, DO
NOT run engine at 3,000 R P M .
REMOVAL
(1) Remove the oil pan.
(2) Remove the oil pump from rear main bearing
cap.
DISASSEMBLE
(1) Remove the relief valve as follows:
(a) Remove cotter pin. Drill a 3.175 mm (1/8
inch) hole Into the relief valve retainer cap and in­
sert a self-threading sheet metal screw.
(b) Clamp screw into a vise and while supporting
oil pump, remove cap by tapping pump body using
a soft hammer. Discard retainer cap and remove
spring and relief valve (Fig. 4).
Fig. 4 Oii Pressure Relief Valve
(2) Remove oil pump cover (Fig. 5).
(3) Remove pump outer rotor and inner rotor with
shaft (Fig. 5).
(4) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump assembly if cover is scratched
or grooved.
Lay a straightedge across the pump cover surface
(Fig. 6). If a 0.088 mm (0.0015 inch) feeler gauge can
be inserted between cover-and
straightedge, pump assembly should be replaced.
INNER.:ROTOR DI5JMBUIOR" DRIVESH"AFT
::CHAMFERED '
EDGE RY10B
Fig. 5 Oil Pump
Fig. 6 Checking Oil Pump Cover Flatness
Measure thickness and diameter of OUTER rotor.
If outer rotor thickness measures 20.9 mm (0.825
inch) or less or if the diameter is 62.7 mm (2.469
inches) or less, replace outer rotor (Fig. 7).
Fig. 7 Measuring Outer Rotor Thickness
If inner rotor measures 20.9 mm (0.825 inch) or
less, replace inner rotor and shaft assembly (Fig. 8).
Slide outer rotor into pump body. Press rotor to the
side with your fingers and measure clearance be­
tween rotor and pump body (Fig. 9). If clearance is
0.356 mm (0.014 inch) or more, replace oil pump as­
sembly.