1994 JEEP CHEROKEE Service Repair Manual

Some suspected converter housing fluid leaks may
not be leaks at all. Residual fluid in the housing, or
excess fluid spilled during factory fill or refill after
repair can be mistaken for a leak. In addition, a rear
main seal leak can also be mistaken for a pump seal
leak if care is exercised.
Converter housing leaks have several potential
sources. Through careful observation, a leak source
can be identified before removing the transmission
for repair.
Pump seal leaks tend to move along the drive hub
and onto the rear of the converter. Pump O-ring or
pump body leaks follow the same path as a seal leak
(Fig. 9).
Pump vent or pump attaching bolt leaks are gener-
ally deposited on the inside of the converter housing
and not on the converter itself (Fig. 9).
Pump seal or gasket leaks usually travel down the
inside of the converter housing.
Front band lever pin plug leaks are generally de-
posited on the housing and not on the converter.
LEAK DIAGNOSIS PROCEDURE
(1) Raise the rear of the vehicle and allow accumu-
lated fluid to drain out of the converter housing.
(2) Check and adjust the transmission fluid level.
(3) Raise the vehicle. Remove the converter hous-
ing dust cover and wipe as much fluid as possible
from the converter housing.
(4) Fabricate a test probe (Fig. 10). Then attach
the probe to the converter housing with one of the
dust shield bolts (Fig. 10).
(5) Have a helper run the engine at 2500 rpm
(with the transmission in Neutral) for two minutes;
then stop the engine.
(6) Inspect the test probe and converter housing. If
a leak is evident, note the color of the fluid. Trans-
mission fluid is red. Engine oil ranges in color from
brown to green, or to black when the oil is dirty.(7) If the probe upper surface is dry, the converter
and seal are not at fault. A path of fluid across the
probe upper surface indicates a converter or seal
leak. Fluid leakingunderthe probe is coming from
the pump housing area (Fig. 11).
(8) Fluid leaking under the probe could be from
the: pump seal and/or bushing, pump vent, kickdown
lever shaft access plug, pump bolts, or porous spots
in the pump body or transmission case (Fig. 11).
(9) If porous spots in the transmission case or
pump body are the suspected leak source, pressurize
the transmission as described in Leak Testing With
Air Pressure.
LEAK TESTING WITH AIR PRESSURE
This test involves closing off the transmission
openings and pressurizing the transmission to 8 psi
with Air Pump Tool 7700. A soapy water solution is
applied to suspected leak points before and during
the pressure test. Leaks will be indicated by the
presence of air bubbles coming through the solution.
Some transmission openings such as the fill tube
and front cooler line fitting can be closed off with a
rubber plug or similar device. Plugs can secured with
wire or duct tape.
Fig. 9 Typical Converter Housing Leak Paths
Fig. 10 Leak Test Probe
Fig. 11 Pump Area Inspection Points
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The transmission rear output shaft opening is
closed off simply by leaving the transfer case bolted
in place. However, if the transfer case has been re-
moved, a shipping plug can used to close off this
opening.
The torque converter hub opening in the pump and
the pump vent require special tools to close them off.
The converter hub seal cap is made from thin wall
tube anda3mm(1/8 in.) thick disc (Fig. 12). A re-
taining strap is needed to secure the seal cup for
testing. The strap can be made from 32 mm (1-1/4
in.) wide stock (Fig. 13). The strap attaching hole po-
sitions are approximate only. Measure hole position
on the converter housing before drilling.
The pump vent tool is made from 6 mm (1/4 in.)
rod and 5 mm (3/16 in.) plate (Fig. 14). The fabri-
cated tools can all be made from mild steel or alumi-
num stock.
AIR PRESSURE LEAK TEST PROCEDURE
(1) Install vent plug, converter hub seal cup and
cup retaining strap (Fig. 15).(2) Close off remaining transmission openings with
rubber plugs, or stoppers.Do not close off rear
cooler line fitting. Air pump will be attached to
this fitting.
(3) Attach Air Pump 7700 to rear cooler line fit-
ting. Connect length of copper tube to fitting. Then
attach air pump hose to tube with hose clamp (Fig.
16).
(4) Apply thick soapy water solution to suspected
leak areas.
CAUTION: The recommended test pressure is 8
psi. The maximum allowable test pressure is 10 psi.
Do not exceed specified test pressure.
(5) Pressurize transmission to 8 psi with air pump.
(6) Observe suspected leak areas. Air bubbles ap-
pearing in soapy water solution indicate leak points.
(7) Remove test tools and plugs after test comple-
tion and make necessary repairs as described in Leak
Correction procedure.
Fig. 12 Converter Hub Seal Cup
Fig. 13 Seal Cup Retaining Strap
Fig. 14 Pump Vent Plug
Fig. 15 Vent Plug And Hub Seal Cup Installation
J30RH/32RH TRANSMISSION DIAGNOSIS 21 - 75

CONVERTER HOUSING AREA LEAK
CORRECTION
(1) Remove converter.
(2) Tighten front band adjusting screw until band
is tight around clutch retainer. This prevents
clutches from coming out when oil pump is removed.
(3) Remove oil pump and seal. Inspect pump hous-
ing drainback and vent holes for obstructions. Clear
holes with solvent and wire.(4) Inspect pump bushing and converter hub. If
bushing is scored, replace it. If converter hub is
scored, either polish it with crocus cloth or replace
converter if scoring is severe.
(5) Install new pump seal, O-ring, gasket, bushing.
Replace oil pump if cracked, porous or damaged in
any way.
(6) Loosen kickdown lever pin plug two turns. Ap-
ply Permatex No. 2 or equivalent to plug threads and
tighten plug to 17 Nzm (150 in-lbs) torque.
(7) Adjust front band.
(8) Lubricate pump seal and converter hub with
transmission fluid or petroleum jelly and install con-
verter.
(9) Install transmission.
(10) Install converter housing dust shield and
lower vehicle.DIAGNOSIS GUIDES AND CHARTS
The diagnosis charts provide additional reference
for transmission diagnosis.
The hydraulic flow charts outline fluid flow and hy-
draulic circuitry. Circuit operation is provided for all
gear ranges. Normal working pressures are also sup-
plied for each of the various gear ranges.
Fig. 16 Pressurizing Transmission
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