TRUCK SERVICE MANUAL
6. Remove by-pass valve from filter mounting head, if so
REPAIR (HEADER LEAKS)
equipped, inspect disc, spring and seat for wear or
Header leaks may occur where tubes protrude through
plate or where header is soldered into case. Repair
7. Remove damaged dowel pins with ST-1 134 Dowel
damaged tubes by inserting a smaller outside diameter
tube inside damaged tube. Cut and flare ends; then
8. If drive shaft is worn beyond worn replacement limits
solder securely. Do not damage tubes or header
or gear is chipped or worn, press shaft from gear.
material with heat while soldering. If more than 5% of
9. Inspect all gears for worn or broken teeth, all parts for
tubes are defective, discard element.
pitting or cracks and body(s) for distorted threads.
10. Check gasket mating surfaces for flatness, nicks or
burrs. Replace all unserviceable parts.
1. Lubricate new rubber "O" ring (3, Fig. 7-9), using
11. Inspect bushings in body(s), cover and idler gear(s),
appropriate mandrel, place in groove at bottom of
if bushings are damaged or worn larger than worn
housing (2). Make sure ring is fully seated, not twisted
replacement limits replace as follows:
and is free of cuts or nicks.
a. Remove bushings with ST-1 158 Bushing Mandrel.
2. Push element (1) carefully into housing, aligning index
b. Press new bushings into gear(s), body or cover, as
marks on housing and element,
required, with ST-1158 Mandrel. Bushings must be flush
3. Press second "O" ring around top of element with
to 0.020 inch [0.51 mm] below surface of gear(s), body or
equal pressure around ring circumference.
4. Place retainer ring (4) over rubber "O" rings.
c. Bore new bushings to specifications as listed in Table
5. Assemble new gaskets, cooler, cover and support;
(1) with appropriate boring machine.
capscrews to 30 to 35 ft-lbs [4.1 to 4.8 kg m] torque.
1. If removed, press large end of idler shaft in gear
pocket side of pump body using deep end of ST-1157
Lubricating oil pumps used on 855 C.I.D. Cummins
Spacer Mandrel where applicable. If mandrel is not
Engines are disassembled, assembled and inspected in
used, press idler shaft in to protrude as listed in Table 7-
a like manner. Care must be taken during disassembly
to mark or identify parts, such as pressure regulator
2. Press driven gear onto drive shaft with shallow end of
plunger, idler shaft, drive shaft, capscrews as to length,
ST-1157 Mandrel. If mandrel is not used, press gear
size, location, etc., as removed to aid in reassembly.
onto shaft so protrusion meets specifications, Table 7-5
Clean disassembled pump in an approved cleaning
solvent as described in Engine Disassembly, Group 0.
3. Lubricate drive shaft, position drive shaft and gear into
DISASSEMBLY AND INSPECTION
pump body. Support drive shaft on a suitable arbor
1. Remove pump cover or filter head from pump body.
press and press drive gear or coupling (Scavenger
Tap lightly with a soft hammer to loosen from dowel.
Pump) on drive shaft.
2. Remove idler gear, press drive shaft through driven
Note: Coupling protrusion or drive gear to body press fit
gear, remove shaft and gear or coupling (Scavenger
clearance should meet specifications in Table 7-5 (2).
4. Lubricate idler shaft and place gear on shaft.
Note: Double lubricating oil pumps have a scavenger
Note: On double lubricating oil pumps, install scavenger
pump body that must be removed after drive shaft is
pump body, using new gasket, and press scavenger
pressed through driven gear. After removing scavenger
driven gear onto drive shaft, leave 0.002 to 0.004 inch
body repeat Step 2.
[0.05 to 0.10 mm] clearance between gear surface and
3. If piston cooling tube, on pumps so equipped, is
bottom of gear pocket. Repeat Step 4.
mutilated, drive or press out from inside body.
5. If removed, (piston cooled engine pumps), press new
4. Press idler shaft from body if worn beyond worn
piston cooling oil tube into pump body with beveled edge
replacement limits as listed in Table 7-5 (2).
up. Protrusion should be as listed in Table 7-5 (3).
5. Remove pressure regulator cap, spring and plunger,
6. Install new dowels in pump body, if removed.
check plunger for freedom of movement in pump body.