Paragraphs 320-321
ALLIS-CHALMERS
outside, it may have been in the sys-
tem originally, or it may show up as
the result of wear or partial failure of
some part of the system. The presence
of gummy deposits however usually
results from inadequate fluids or from
failure to drain and renew the fluid at
the recommended intervals. These
principles should be kept in m,ind
when shooting trouble on any of the
existing systems and also when per-
forming repair work on pumps, valves
and cylinders. Thus when disassem-
bling a pump or-valve unit, it is good
practice generally to not remove any
parts which can be thoroughly in-
spected while they are installed. In-
ternal parts of pumps, valves and cyl-
inders when removed should be han-
dled with the same care as would be
accorded the parts of a diesel pump or
injector and should be soaked or man-
ually cleaned with an approved sol-
vent to remove gum deposits. Unless
you practice good housekeeping
(cleanliness) in your shop do not un-
dertake the repair of hydraulic equip-
ment,
HYDRAULIC PUMP
MODELS B-C
In cases of faulty operation of the
pump valves the unit can oftentimes
be corrected without disassembly by
removing it from the tractor and
flushing it with a petroleum solvent or
gasoline.
320.
R&R AND INSPECTION, Re-
moval of the pump from the pto hous-
ing is accomplished by disconnecting
the hose lines and controls and remov-
ing the bolts or screws which retain it
to the pto housing. Removal of the
pump driving camshaft which is in-
tegral with the pto shaft is done by
following the procedure outlined in
paragraphs 311 and 312.
Procedure for bench disassembly of
the pump is as follows:
Plungers can be lifted out of their
cylinders after removing the cam arm
pins (27—Fig. AC:60 or AC161) which
are retained by hair pin locks.
Inlet valves are removed by un-
screwing the valve plugs (22) and
pulling the internally threaded seat
inserts (37) down with a sleeve and
puller screw threaded into the in-
sert. If seat inserts are not threaded
they can be driven out using a drift
1/32 inch smaller in diameter than the
O.D. of the insert. This method usually
calls for a renewal of the insert be-
cause of damage done during removal.
Discharge valves (3) can be re-
moved by same methods used on inlet
valves after removing valve plugs (5)
I 2
27
13
23
Fig,
AC160~Models B, and
C
power lift hydraulic pump which is of the two plunger type.
Pump is mounted on right side o# accessory units housing.
10.
Relief valve ball 19. Intake valve insert
11.
Relief valve spring pin
plunger 20. Intake \
1.
Pump body
2.
Discharge valve insert
3.
Discharge valve ball
4.
Discharge valve
spring
5.
Discharge valve plug
6. Relief valve plug
7.
Control rod
8. Outlet connection
9. Relief valve insert
12.
Relief valve thimble
13.
Control shaft
14.
Torsion spring
15.
Retaining pin
16.
Shaft oil seal
17.
Plunger sprinff
18.
Access plug
20.
intake valve sleeve
21.
Intake valve ball
22.
Intake valve plug
23.
Intake pipe
24.
Plunger
25.
Cam arm
26.
Cam roller
27.
Cam arm pin
springs and balls. These valves are
removed through top of housing.
Control shaft (13) is removed by
first removing the washers and torsion
spring (14). Turn shaft to *lift** posi-
tion where thimble (12) is at highest
point of its travel then withdraw shaft
from pump body.
Relief valve insert (9) can be
bumped out of top of pump after re-
moving top and bottom plugs, ball,
spring and plunger (11).
Plungers and cylinder bores must be
free of roughness or deep scratches.
Recommended plunger to cylinder
clearance is .0002. Check cam follow-
ers for wear or roughness and reject
any rollers which have more than .010
clearance on journal pin. Check the
valve seats and balls for grooves, pit-
ting or other leak producing condi-
tions oil leakage occurring between
control shaft and its bore in body will
show up at drilled passage between
plungers in line with control shaft
bore.
321.
OVERHAUL AND TEST. If
valve seat inserts were removed by
bumping, new inserts will probably be
needed.
CONTROL SHAFT. Assemble the
control shaft to the lever so that
stop for adjusting screw in lever is
toward fiat on control shaft. Insert
shaft ihto body with flat on shaft up
and with torsion spring wound
Vz
turn
so as to return the control shaft to
*'hold" position.
RELIEF VALVE. With control shaft
in lowering position install in order
thimble (12), spring (32) and plung-
er (11). Before installing the seat in-
sert, seat the ball to same by tapping
lightly with a hammer and soft drift.
Install the seat insert, drop ball into
cupped end of plunger then carefully
press seat into body until top of in-
sert (9) is 9/16 inch below top of hole.
DISCHARGE VALVES. Press or
bump discharge valve seat insert into
pump body until it bottoms. Discharge
valve plugs of three different lengths.
Fig. AC162, have been used in the
three different pump bodies used at
various times during the production
of the B and C tractors. When the cor-
rect plug is used the ball end of same
will contact the spring and hold the
ball on its seat when plug is screwed
all the way down. If ball rattles when
pump is shaken or if plug cannot be
screwed all the way to its seat on
pump body the plug is incorrect for
that particular pump. The different
plugs are procurable under number
213471 short; 213005 medium; 211360
long.
INLET VALVES. Install seat inserts
up into body until top of insert pin
just clears the plunger spring (17).
88
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