Oil Pan And Rocker Arm Covers - GMC T Series 1994 Repair Manual

Figure 27— Replacing the Crankshaft Sprocket
COOLANT PUMP
ljj* | Clean
• Old gasket from the gasket surfaces.
Notice: Do not immerse the pump in solvent
The solvent may enter the pum p's perma­
nently lubricated bearings and cause prema­
ture bearing failure.
Inspect
Coolant pump shaft for rotation and end play. The
shaft and fan hub should turn straight and smooth­
ly. If the hub wobbles or the shaft is noisy or feels
" lumpy" when turned, replace the coolant pump. If
the shaft end play exceeds 0.381 mm (0.015 inch),
replace the coolant pump.
1. Shaft Extension
2. Pump Body
3. Drive Gear and Shaft
4. Idler Gear
5. Pump Cover
6. Pressure Regulator Valve
7. Pressure Regulator Spring
8. Retaining Pin
9. Screws
10. Pickup Screen and Pipe
Figure 28— Oil Pump Components
» Coolant pump body at the drain (weep) hole. Slight
staining around the weep hole is normal. Replace
the coolant pump only if coolant is dripping from
the weep hole while the engine is running or while
the system is pressurized.
OIL PAN AND ROCKER ARM
COVERS
Parts in solvent. Remove all sludge and varnish.
Old gaskets from the gasket surfaces.
Inspect
1?
• Gasket flanges for bending or damage.
• Rubber grommets and parts on the rocker arm cov­
er for deterioration.
• Oil pan for rock damage or cracks.
• Oil pan baffle for lack of fit.
• Drain plug threads for stripping.
OIL PUMP
Remove or Disconnect (Figure 28)
1. Shaft extension (1).
• Do not remove the pickup pipe and screen unless
replacement is required.
• The pickup pipe has a press fit in to the pump
cover.
• Do not remove the screen from the pipe. The pick­
up screen and pipe are serviced as a complete
assembly only.
2. Pickup pipe and screen (10).
3. Screws (9).
4. Pump cover (5).
• Mark where the idler gear (4) and drive gear (3)
mesh together, so they can be reinstalled with the
same gear teeth indexed.
5. Idler gear (4) and drive gear (3).
B9445