TRUCK SERVICE MANUAL
FUEL SYSTEM
Front Drive Cover And Governor Plunger
Governor Spring-Pack Cover
1. To remove drive cover from main housing, tap edge of
1. Remove spring-pack cover from main housing, lift off
cover lightly with a plastic hammer to loosen. Lift cover off
cover and discard gasket.
dowels and discard gasket.
2. For disassembly of spring-pack, see Spring-Pack
section.
Note: Never use a steel hammer on aluminum, or on a
General
finished surface, it can cause extensive damage.
3. Remove weight assist plunger, spring and shims from
Fuel pump sub-assembly repair, cleaning, inspection and
weight carrier assembly. Slide governor plunger from
rebuild instructions are listed in the following sections.
barrel.
Worn replacement limits are given to help the mechanic
decide when to replace parts or to use parts that have
Caution: Place plunger where it will not be damaged, a
many hours or miles of useful life.
slight nick can cause extensive damage.
However, parts that are worn beyond replacement limits
must not be re-used.
Throttle Assembly - Drive Screw Cover Plate Type
1. Remove snap ring from inside housing. Remove drive
Cleaning
screws securing cover plate. Pull throttle assembly from
A clean shop, clean tools and good cleaning practices are
housing. Remove "O" ring and discard.
essential to good quality fuel pump repair. Special care
must be taken when cleaning aluminum alloy parts since
Filter Screen
some cleaning solvents will attack and corrode aluminum.
1. Screw off screen cover on top of main housing. Lift
However, cleaning time is always well spent. Most fuel
cap, spring and filter screen assembly from main housing;
pump failures occur because of dirt. Clean all parts before
discard "O" ring.
rebuild or assembly.
Tachometer Drive
Inspection
1. Remove tachometer drive cover screws.
Time spent on inspection is profitable. It can save many
2. Lift drive cover from main housing or front cover.
dollars worth of parts and also prevent failure of the rebuilt
Discard gaskets, when used.
pump.
3. Carefully drive tachometer drive assembly from pump,
Too often inspection is performed too lightly or not
using a brass punch and hammer or use ST-667-10 collet
performed at all. Proper tools are essential to do a
with ST-667 Dowel Puller or use ST-1326 to pull
satisfactory job of inspection.
tachometer seal, shaft and bushing. Fig. 5-15.
4. Remove oil seal and dust seal, when used, from shaft
Tools
and discard.
Using proper tools has many advantages. The fuel pump
consists of several aluminum parts, which makes it light;
Throttle Assembly-Retaining Ring Type
but the parts may be easily damaged if the right tool is not
Compress throttle plate retaining ring and remove from
used to perform the job being done.
groove. Pull throttle assembly from pump. The throttle
Note: Aluminum parts must be handled carefully.
shaft is a select fit in its sleeve and sizes are identified by
color code.
Service tools may be purchased from your Cummins
Distributor if you perform your own rebuild work.
Note: Handle throttle shaft with care.
An arbor press should be used for all pressing operations to
control pressure and alignment. Always make sure that the
part is properly supported when pressing in another part,
the parts can easily be damaged beyond repair if not
properly supported.
Pressing Lubricant
A high pressure lubricant should be used on mating
surfaces In all pressing or driving operations. The lubricant
prevents galling or scoring during assembly. Be sure to
remove all burrs from mating parts before pressing
together.
Fig. 5-15, F5300. Removing tachometer drive assembly
with ST- 1326
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