Dodge RAM TRUCK 1500 1995 Service Manual page 1396

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42RH/46RH/47RH TRANSMISSION DIAGNOSIS AND TESTING 21 -113
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.
6).
Pump vent or pump attaching bolt leaks are gener­
ally deposited on' the inside of the converter housing
and not on the converter itself.
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. •
PUMP PUMP PUMP
Fig. 6 Converter Homing Leak Paths
LEAK DIAGNOSIS PROCEDURE
(1) Raise rear of vehicle and allow accumulated
fluid to drain out of converter housing.
(2) Check and adjust transmission fluid level.
(3) Raise vehicle. Remove converter housing dust
cover and wipe as much fluid as possible from con­
verter housing.
(4) Fabricate test probe (Fig. 7). Attach probe to
converter housing with a dust shield bolt.
(5)
Have a helper run engine at
2500
rpm (with
transmission in Neutral) for two minutes; then stop
engine.
(6) Inspect test probe and converter housing. If a
leak is evident, note color of fluid. Transmission fluid
is red. Engine oil ranges in color from brown to
green, or to black when oil is dirty.
(7) If probe upper surface is wet, converter and
seal are not at fault. A path of fluid across probe up­
per surface indicates a converter or seal leak. Fluid
leaking under probe is coming from pump housing
area (Fig. 7).
(8) Fluid leaking under the probe could be from:
pump seal and/or bushing, pump vent, kickdown le­
ver shaft access plug, pump bolts, or porous spots in
pump body or transmission case (Fig. 8).
(9) If porous spots in the transmission case or
pump body are the suspected leak source, pressurize
transmission as described in Leak Testing With Air
Pressure.
SHIELD MATERIAL: 5-1/2" X 1-1/2" X 1/32"
BOLT SHEET METAL RN778
Fig. 7 Leak Test Probe
Fig. 8 Pump Area inspection Points
TORQUE CONVERTER LEAK POINTS
Possible sources of converter leaks are: (a) leaks at
the weld joint around the outside diameter weld and
(b) leaks at the converter hub weld (Fig. 9).
LEAK TESTING WITH AIR PRESSURE
This test involves closing off all openings and pres­
surizing the transmission to 8 psi with Air Pump
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.