2003 FORD MUSTANG transmission fluid

A no-
drive condition can exist even with correct transmission fluid pressure because of inoperative
clutches or bands. An erratic shift can be located through a series of checks by substituting air
pressure for fluid pressure to determine the location of the malfunction.
Follow the procedure to determine the location of the inoperative clutch or band by introducing air
pressure into the various test plate passages.
NOTE: Use only dry, regulated 276 kPa (40 psi) maximum air pressure.
Apply air to the appropriate passage(s). A dull thud should be felt or heard or movement could be
observed when the clutch component applies. There should be no hissing sound when the component
is applied.
Cover the vent hole in the test plate with a clean, lint- free shop towel to prevent spray when the air is
applied. Plugging the vent hole during testing will result in inaccurate results.
1. Drain transmission fluid and remove the transmission fluid pan.
2. Remove the main control valve body.
3. Install transmission test plate and gasket. Tighten bolts to 10 Nm (89 lb- in).
4. NOTE: Do not apply air to the test plate vent hole.
Apply air to the appropriate clutch port (refer to the Transmission Air Test Plate illustration). A
dull thud may be heard or movement felt when the component is applied or released. If clutch
seals or check balls are leaking a hissing sound may be heard.
If the servos do not operate, disassemble, clean and inspect them to locate the source of the concern.
If air pressure applied to the clutch passages fails to operate a clutch, or operates clutches
simultaneously, inspect the fluid passages in the case.
If air pressure applied to the accumulator fails to operate an accumulator, remove and inspect case
passages and piston.
Clutch Pressure Test
The Clutch Pressure Test will diagnose a low- pressure condition or leakage in a clutch circuit. A
difference of 103 kPa (15 psi) or more between the clutch pressure and line pressure will prevent a
normal shift.
1. CAUTION: Pressure gauges affect the shift quality of the transmission. Care must
be taken not to accelerate or decelerate rapidly. Possible transmission failure can result.
Attach 0- 2068 kPa (0- 300 psi) pressure gauges to the line pressure tap and the appropriate
clutch pressure tap according to Band and Clutch Application Chart A&B. Gauges must be
accurate enough to distinguish a 103 kPa (15 psi) difference. (If this test is done in conjunction
with a control pressure test, pressure gauges will be attached to all pressure taps.) Have
sufficient flexible hose available to read the gauges in the vehicle.
2. Drive the vehicle. When pressure is applied to the clutch, note the difference between the line pressure gauge and the corresponding clutch pressure gauge.
3. If the difference in pressures is less than 103 kPa (15 psi), the corresponding clutch circuit does not have a pressure loss. The gauges on the line pressure tap and appropriate clutch pressure
tap can be switched to confirm that gauge calibration differences are not the cause. Klj . 6 ba
72003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Leakage Inspection
CAUTION: Do not try to stop the fluid leak by increasing the torque beyond specifications.
This may cause damage to the case threads.
Check the fluid filler tube connection at the transmission case. If leakage is found here, install a new
grommet.
Check the VSS plug or VSS sensor O-ring (model dependent). If leakage is found install a new O- ring.
Check fluid lines and fittings between the transmission and the cooler in the radiator tank for
looseness, wear, or damage. If leakage cannot be stopped by tightening a fluid tube nut, install new
parts. When fluid is found leaking between the case and cooler line fitting, check for missing or
damaged O- ring, then tighten the fitting to maximum specification.
If the leak continues, install a new cooler line fitting and tighten to specification. The same procedure
should be followed for fluid leaks between the radiator cooler and the cooler line fittings in this section;
refer to Section 307 - 02 .
Check the engine coolant in the radiator. If transmission fluid is present in the coolant, the cooler in the
radiator is probably leaking.
The cooler can be further checked for leaks by disconnecting the lines for the cooler fittings and
applying no more than 345 kPa (50 psi) air pressure to the fittings. Remove the radiator cap to relieve
the pressure buildup at the exterior of the oil cooler tank. If the cooler is leaking and or will not hold
pressure, install a new cooler.
If leakage is found at the transmission range selector lever, install a new seal.
If leakage is found at the transmission internal harness connector, install a new O- ring. 4R70W External Sealing SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Klj . 1 ba
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

Item Part Number Description
1 7902 Torque converter
2 7A248 Front pump seal
3 7A248 Front pump seal
4 N605789-S101 Bolt
5 7A106 Front pump body assembly
6 7A136 Pump gasket
7 390318-
S2 Pipe plug —
1/8 —27 Dryseal tapered 8 7005 Case
9 7034 Vent
10 N811757-S100 Speed sensor seal
11 7H103 Output shaft speed (OSS) sensor
12 7B498 Manual control lever seal assembly
13 7086 Extension housing gasket
14 7A039 Extension housing
15 N803737-S1101 Bolt —
M8-1.25 x 30 15 N606047-S101 Bolt —
M8-1.25 x 70 15 N803521-S1101 Bolt —
M8-1.25 x 1.25 x 0.54 15 N811524-S101 Bolt —
M8-1.25 x 42 16 7052 Oil seal
17 7Z276 Seal —
bulkhead assembly 18 7G276 Bulkhead assembly wiring connector
19 7G276 Molded lead frame
20 7A194 Transmission fluid pan
21 7A191 Gasket Klj . 2 ba
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

Fluid Leakage in Torque Converter Area
In diagnosing and correcting fluid leaks in the front pump support and gear and torque converter area,
use the following procedures to locate the exact cause of the leakage. Leakage at the front of
transmission, as evidenced by fluid around the torque converter housing, may have several sources.
By careful observation it is possible, in many instances, to pinpoint the source of leak before removing
the transmission from the vehicle. The paths which the fluid takes to reach the bottom of the torque
converter housing are shown in the illustration. The five steps following correspond with the numbers
in the illustration.
1. Fluid leaking by the front pump seal lip will tend to move along the impeller hub and onto the back of the impeller housing. Except in the case of a total seal failure, fluid leakage by the lip of
the seal will be deposited on the inside of the torque converter housing only, near the outside
diameter of the housing.
2. Fluid leakage by the outside diameter of the front pump seal and front pump body will follow the same path that leaks by the inside diameter of the front pump seal follow.
3. Fluid that leaks by a front pump to case bolt or pump gasket will be deposited on the inside of the torque converter housing only. Fluid will not be deposited on the back of the torque
converter.
4. Fluid leakage from the converter drain plug, (model dependent) converter seal weld or converter to flexplate stud weld will appear at the outside diameter of the torque converter on the back
face of the flexplate and in the converter housing only near the flexplate. Fluid leaks from the
torque converter will leave a ring of fluid around the inside of the torque converter housing.
5. NOTE: White facial tissue paper may aid in determining the color (red is transmission fluid) and
source of the leaking fluid.
Engine oil leaks are sometimes incorrectly diagnosed as transmission pump gasket leaks. The 22 7D273 Fluid tube connector
23 87650-S2 Converter drain plug Klj . 3 ba
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

following areas of possible leakage should also be checked to determine if engine oil leakage is
causing the concern.
a. Leakage at the engine valve cover gasket may allow oil to flow over the torque converter housing or seep down between the torque converter housing and cylinder block causing oil to
be present in or at the bottom of the torque converter housing.
b. Oil galley plug leaks will allow oil to flow down the rear face of the cylinder block to the bottom of the torque converter housing.
c. Leakage at the crankshaft rear oil seal will work back to the flexplate, and then into the torque converter housing.
d. Leakage at engine oil pressure sensor.
Leak Check Test 1. Remove the fluid level indicator and note the color of the fluid. Original factory fill fluid is dyed red to aid in determining if leakage is from the engine or transmission. Unless a considerable
amount of makeup fluid has been added or the fluid has been changed, the red color should
assist in pinpointing the leak.
2. Remove the torque converter housing cover. Clean off any fluid from the top and bottom of the torque converter housing, front of the case and rear face of the engine and oil pan. Clean the
torque converter area by washing with a suitable nonflammable solvent and blow dry with
compressed air.
3. Wash out the torque converter housing, the front of the flexplate and the converter drain plugs. The torque converter housing may be washed out using cleaning solvent and a squirt- type oil
can. Blow all washed areas dry with compressed air.
4. Start and run the engine until the transmission reaches its normal operating temperature. Observe the back of the cylinder block and top of the torque converter housing for evidence of
fluid leakage. Raise the vehicle on a hoist; refer to Section 100 - 02 and run the engine at fast
idle, then at engine idle, occasionally shifting to the Overdrive and Reverse ranges to increase
pressure within the transmission. Observe the front of the flexplate, back of the cylinder block
(in as far as possible), and inside the torque converter housing and front of the case. Run the
engine until fluid leakage is evident and the probable source of leakage can be determined.
Leak Check Test With Black Light Used With 12 Volt Master UV Diagnostic Inspection Kit
Oil soluble aniline or fluorescent dyes premixed at the rate of 2.5ml (1/2 teaspoon) of dye powder to
0.235L (1/2 pint) of transmission fluid have proved helpful in locating the source of fluid leakage. Such
dyes may be used to determine whether an engine oil or transmission fluid leak is present, or if the
fluid in the fluid cooler leaks into the engine cooling system. A black light must be used with the
fluorescent dye solution. Klj . 4 ba
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Transmission Fluid Cooler
CAUTION: Whenever a transmission has been disassembled to install new parts, the
cooler bypass valve (CBV), all transmission fluid coolers (in tank and auxiliary) and
transmission fluid cooler lines must be cleaned and backflushed. Use a suitable the torque
converter/fluid cooler cleaner.
NOTE: Cleaning and backflushing the transmission fluid cooling system along with following all the
normal cleaning and inspection procedures in this section during disassembly and reassembly will
keep contamination from reentering the transmission and causing a repeat repair.
When internal wear or damage has occurred in the transmission, metal particles, clutch plate material,
or band material may have been carried into the torque converter and transmission fluid cooler. These
contaminants are a major cause of recurring transmission troubles and must be removed from the
system before the transmission is put back into use.
Transmission Fluid Cooler Flow Test
NOTE: The transmission linkage/cable adjustment, fluid level and line pressure must be within
specification before carrying out this test. Refer to Section 307 - 05 for adjustments.
1. Remove fluid level indicator from fluid filler tube.
2. Place funnel in fluid filler tube.
3. Position the vehicle on a hoist. For additional information, refer to Section 100 - 02 .
4. Remove the cooler return line (top fitting) from the fitting on the transmission case.
5. Connect one end of a hose to the cooler return line and route other end of the hose up to a point where it can be inserted into the funnel at the fluid filler tube.
6. Remove the safety stands and lower the vehicle. Insert end of hose into the funnel.
7. Start the engine and run it at idle with the transmission in NEUTRAL.
8. When fluid flows from the hose in a steady stream, a liberal amount of fluid should be observed. "Liberal" is about 1 liter (1 quart) delivered in 15 seconds. If a liberal flow is observed, the test is
complete.
9. If the flow is not liberal, stop the engine. Disconnect the hose from the cooler return line and connect it to the converter outlet fitting (bottom fitting) on the transmission case.
10. Repeat steps 6 and 7. If flow is now approximately 1 liter (1 quart) in 15 seconds, refer to Transmission Fluid Cooler — Backflushing and Cleaning in this section. If the flow is still not
approximately 1 liter (1 quart) in 15 seconds, repair or install pump and or converter.
For the installation of new transmission fluid cooler or tubes, refer to Section 307 - 02 .
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Diagnosis By Symptom
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Special Tool(s)
Transmission Fluid Pressure
Gauge
307-
004 (T57L-77820- A) Air Test Plate, Transmission
307-
246 (T92P-7006- A) Breakout Box, EEC-V Control
System
418- 049 (T94L-50- EEC-V) or
equivalent MLP-
TR Cable
418- F107 (007- 00111) or
equivalent Worldwide Diagnostic System
(WDS)
418-
F224
New Generation STAR (NGS)
Tester
418- F052 or equivalent scan
tool Transmission Tester
307-
F016 (007- 00130) or
equivalent Trans Tester TR/MLP Overlay
and Manual
007-
00131 or equivalent 73 III Automotive Meter Klj . 1 ba
312003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...

Condition.
Shift Linkage
·
Damaged or incorrectly
adjusted ·
Inspect and repair as required. Verify transmission shift cable
adjustment; refer to Section 307 - 05 . Adjust transmission shift cable
as necessary. After repairing transmission shift cable, verify the digital
transmission range (TR) sensor is correctly adjusted. Adjust the
digital TR sensor as necessary. Incorrect Pressures
·
Low forward clutch
pressure, low line
pressure ·
Check pressure at line and forward clutch tap. Refer to Line Pressure
Chart for specification. If pressures are low, check the following
components: oil filter and seal assembly, main controls, pump
assembly, forward clutch assembly. Fluid Filter and Seal
Assembly
·
Plugged, damaged ·
Install a new filter and seal assembly. ·
Filter seal damaged Main Controls
·
3- 4 shift valve, main
regulator valve, manual
valve — stuck,
damaged ·
Inspect for damage. Repair as required. ·
Bolts not tightened to
specifications ·
Tighten bolts to specifications. ·
Gaskets damaged ·
Inspect gaskets for damage and install a new gasket. ·
2- 3 accumulator and
seals damaged ·
Inspect piston, seals and bore for damage. Repair as required. ·
Pressure regulator
valve ·
Inspect the diameter for wear. Pump Assembly
·
Bolts not tightened to
specifications ·
Tighten bolts to specifications. ·
Porosity/cross
leaks/ball missing or
leaking, plugged hole ·
Inspect for porosity and leaks. Repair as required. ·
No. 3 and No. 4 seal
rings damaged ·
Inspect seals for damage. Repair as required. ·
Gaskets damaged ·
Inspect for damage and install a new gasket. Forward Clutch
Assembly
·
Seals, piston damaged ·
Inspect seals for damage. Repair as required. ·
Check balls damaged,
missing, mislocated,
not seating correctly ·
Inspect for mislocation, poor seating, damage. Install a new cylinder
as required. ·
Friction elements
damaged or worn ·
Check for abnormal wear, damage. Repair as required. One-
Way Clutch
Assembly (Planetary) ·
Worn, damaged or
assembled incorrectly ·
Inspect for damage. Repair as required. Output Shaft Klj . 4 ba
312003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2748/S3B~us~en~ ...