My clutch pedal wont spring back once i've released it. I've replaced the clutch, clutch fork & clips, throw-out bearing, clutch master cylinder, and even a slave cylinder. On top of all that, i've also bled my lines ALOT. I bought another master cylinder thinking the original one I had purchased was defective...but still no luck. Any ideas??

It's time to change the clutch with entire kit. Release bearing, pilot bearing, clutch plate, pressure plate and get flywheel turned. If that bearing flies apart inside your transmission it will leave you stranded and your release fork will be destroyed possibly causing more damage to the transmission housing. It is hydraulic and if the master cylinder is working properly you're not likely to notice any play in the pedal due to release bearing.

Well, it would shift easily with engine off, because the transmission input shaft is not turning. Engine running and clutch engaging good, the input shaft would again be stationary and allow smooth shifting.
What you have to determine is if the clutch disc or pressure plate is bad (a new clutch is needed), or if the pedal hydraulic system has a malfunction. When you push the pedal down, a rod from the top of pedal pushes into the clutch master cylinder bolted to the firewall under the hood. This cylinder has a reservoir filled with brake fluid. When the rod forces fluid from the clutch master down a steel line and into the clutch slave cylinder down on the transmission bell housing, the hydraulic pressure forces a plunger from the slave cylinder to extend and push the clutch fork lever a small amount, enough to force the clutch release bearing (aka throw-out bearing) against the pressure plate. This relieves pressure on the clutch disc and input shaft becomes stationary for easy shifting.

I hate to say this some clutch plates you can not tell the difference from the flywheel side so it will go on backwards ,sounds crazy,but I have seen people put them on backwards all the time and that is what it sounds like considering you have done enough for it to work,FLYWHEEL SIDE XXXXXX

There should have been a clip to secure the bearing on the fork shaft. Was it secure??
Clutch may not engage if clutch master cylinder or clutch slave have not been properly bled. There is no adjustment on hydraulic systems. Bleed again if necessary.
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SECTION 308-00: Manual Transmission/Transaxle and Clutch - General Information 1998 Contour/Mystique Workshop Manual DESCRIPTION AND OPERATION Manual Transaxle and Clutch Manual Transaxle and Clutch - General Information This section covers general procedures for diagnosis and testing the clutch system. For additional information, refer to Section 308-01 . For specified clutch system service procedures. For additional information, refer to Section 308-02 . For a complete description of the manual transaxle. For additional information, refer to Section 308-03 .
The clutch system includes:

• Flywheel.
• Clutch disc.
• Clutch pressure plate.
• Clutch master cylinder.
• Clutch slave cylinder.
• Clutch release fork.
• Clutch release hub and bearing.

The clutch master cylinder transmits fluid pressure to the slave cylinder, which in turn moves the clutch release fork and the clutch release hub and bearing.
The clutch master cylinder uses brake fluid and shares a common reservoir with the brake master cylinder
The clutch is a single plate, dry-friction disc with a diaphragm-style spring clutch pressure plate. The clutch disc has a hub which is splined to the input shaft. The clutch disc has friction material where it contacts the flywheel and the clutch pressure plate. Torsion springs on the clutch disc help absorb the engine torque pulses. The clutch pressure plate applies pressure to the clutch disc, holding it tightly against the surface of the flywheel.
In the engaged position, the diaphragm spring holds the clutch pressure plate against the clutch disc, so that engine torque is transmitted to the input shaft. When the clutch pedal is depressed, the clutch release hub and bearing pushes the diaphragm spring center toward the flywheel. The diaphragm spring pivots at the fulcrum, relieving the load on the clutch pressure plate. Steel spring straps riveted to the clutch pressure plate cover pull the clutch pressure plate from the clutch disc, disengaging the engine torque from the transaxle and enabling the gears to be changed.
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Inspection and Verification - MTX-75
The following checks should be carried out before repairing or replacing the transaxle:
Poor gear shifting

1. Check the operation of the clutch: Lay a block of wood approx. 25 mm thick under the clutch pedal and depress the clutch pedal as far as the stop. If 1st or 2nd gear can be selected with no problem with the engine running and the parking brake applied, the clutch is OK. If the gear cannot be selected, repair the clutch.

1. Check the selector mechanism:
   • The free play in the gearshift lever must be no more than 15 mm.
     • If the gearshift lever free play is too great, check the gearshift cables and replace them if necessary.
   • If the gearshift lever free play is OK, adjust the gearshift linkage. For additional information, refer to Section 308-06 .

1. Check the transaxle fluid level and top up with Automatic Transmission Fluid ESD-M2C186-A if necessary.

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POSSIBLE CAUSES TO YOUR CLUTCH PEDAL PROBLEM. COULD BE BRAKE FLUID LEVEL LOW CAUSING YOU TO GET AIR IN THE HYDRALIC SYSTEM.IF FLUID WAS LOW CHECK FOR FLUID LEAKS AROUND LINES TO CLUTCH MASTER CYLINDER AND CLUTCH SLAVE CYLINDER.IF FLUID LEVEL ALL GOOD. LOOK FOR A BROKE CLUTCH RELEASE BEARING OR FORK.CHECK FOR BROKEN DIAPHRAGM SPRING IN CLUTCH PRESSURE PLATE.

Can you put it in gear with the engine off? You could have a broken clutch fork, failed master/slave cylinder, hydrolic leak, or a busted throw-out bearing. If the clutch fluid is full you know you don't have a leak. Some Fords use the brake fluid reservoir for the clutch master cylinder. If you can see your slave cylinder, have someone push the clutch while you look for movement. If it moves about one inch then you'll be taking the transmission out to replace the clutch and/or throw-out bearing.

If this is a hydraulic clutch, ask your mechanic to change the master cylinder (slave cylinder). This could have a leak (which he/she should have found, and checked this). If not, the cable may be too loose, or is not hooked up correctly.

Please let me know if you need further assistance.

carsandcomps,

Guru, Premium Expert @ Fixya.com

If the car hasn't been driven for a while it could be corrosion on the fork but I think that is unlikely. I think you are right about the release bearing being jammed in the spring. If the truck has quite high mileage, it probably means a clutch job.

is there adjustment under the dash at the pedal for the problem it may be a worn out return spring re check the lines for all air to have been bled out again.