Thread Repair - GMC T Series 1994 Repair Manual

DRILL HOLE TO
PROPER SIZE
Assemble
1. Lubricate all internal parts with engine oil during
assembly.
NOTICE:
To avoid engine damage,
cavities must be packed with petroleum jelly
before
installing the gears to assure priming.
• Pack all pump cavities with petroleum jelly.
2. Pump gears.
NOTICE:
To avoid engine damage, use
original equipment gaskets. Gasket thickness is
critical
to proper functioning of the pump.
3. Cover and gasket.
Tighten
• Cover bolts to 10 N*m (89 lbs. in.).
4. Pressure regulator valve, spring and retaining
pin.
Important
Whenever the oil pump is overhauled, clear the oil
pan of oil and sludge, replace the oil filter and fill
crankcase with clean oil.
Inspect
1. Remove the oil pressure sending unit and install a
pressure gage.
NOTICE:
If the oil pressure does not build up
almost immediately, remove the oil pan and
check oil pump suction pipe attachment to the
pump. If necessary, dismantle the oil pump, fill
all cavities with petroleum jelly and reassemble.
Running the engine without measurable oil
pressure will cause extensive damage.
2. Start engine and observe oil pressure.
TAP HOLE TO
PROPER SIZE
Figure 46 - Repairing Threaded Holes
Figure 46
drilling out, rethreading and installing a suitable thread
all
pump
insert.
only
INSTALL INSERT
ON MANDREL

THREAD REPAIR

Damaged threads may be reconditioned by
Tools Required:
General purpose thread repair kits are
available commercially.
CAUTION: Wear safety glasses to
avoid eye damage.
Determine size, pitch and depth of damaged
1.
thread. If necessary, adjust stop collars on cutting
tool and tap to the required depth.
9
Important
• Refer to the kit manufacturer's instructions
regarding the size of drill and tap to be used.
2. Drill out damaged thread. Clean out chips.
3. Tap hole. Lubricate tap with light engine oil.
Clean the thread.
m Important
• Avoid buildup of chips. Back out the tap every
few turns and remove chips.
4. Thread the thread insert onto the mandrel of the
installer, refer to Figure 46. Engage the tang of
the insert onto the end of the mandrel.
5. Lubricate the insert with light engine oil (except
when installing in aluminum) and install.
m Important
• When correctly installed, the insert should be
flush to one turn below the surface.
6. If the tang of the insert does not break off when
backing out of the installer, break the tang off
with a drift pin.
INSTALL INSERT
INTO NEWLY
THREADED HOLE
M40066— 6A7— W - E D S