[215 Sw] Water Pump; [219 Mu] Oil Pump; Disassembly - Mack E7 Service Manual

5-101.bk Page 57 Friday, March 17, 2006 11:05 AM
When pressure-testing complete oil cooler
assembly using an in-line pressure regulator,
apply pressure at 2–5 psi (14–34 kPa) maximum.
Then gradually increase pressure, checking for
leaks until 80 psi (552 kPa) is reached.
Figure 5-69 — Sealing Oil Outlet
1. Housing
2. Plate

[215 SW] WATER PUMP

The water pump is a belt-driven centrifugal or
impeller type, and is located on the front of the
engine. The water pump pulley is belt-driven by
the crankshaft pulley.
200 BENCH PROCEDURES
1
2
3
3
200276a
3. Capscrews
During engine operation, the impeller spins in
proportion to engine speed. The spinning impeller
blades create a negative pressure (suction) at the
water pump inlet port and a positive pressure at
the outlet port. Engine coolant is drawn into the
water pump from the radiator, through the lower
radiator hose. The impeller motion forces coolant
to circulate through the engine block, cylinder
head, and back to the radiator.
To perform water pump service other than
replacement, refer to the COOLING 7.0 manual.

[219 MU] OIL PUMP

The shaft and pumping gear on oil pumps
manufactured after February 1996 are a one-
piece design. Earlier models have a gear
pressed onto a keyed shaft. The shafts are
interchangeable and replacement with a new
(one-piece) shaft is recommended as oil pump
gear-to-housing contact is reduced, resulting in
longer pump life.

Disassembly

Refer to Figure 5-70.
1. Remove pick-up tube and screen assembly
(not shown).
2. Remove oil pump housing cover (7) from oil
pump housing (4).
3. Remove oil pressure relief valve cap (13).
4. Remove oil pressure relief valve spring (12)
and plunger (11).
5. Slide oil pump idler gear (14) off shaft.
6. Turn oil pump upside down and remove oil
pump shaft nut (1) and washer (2).
7. Using a press, remove drive gear (3) and
key (5) from pumping gear and shaft
assembly (6).
8. Remove pumping gear and shaft assembly
from housing.
9. Remove oil pump inlet flange plate (9) and
gasket (8) from housing by removing
capscrews (10).
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