Clutch pedal stays on floor when released

If its a hydrulic clutch there is no adjustment if its not hydrulic the adjustment should be on the side of the tranny

There is a plate under the steering rack behind the sump.

See instructions below from autozone.com. If the clutch still has air after following this procedure, try back bleeding by pushing the slave piston in while the bleeder is open, then closing bleeder before releasing the piston. This is similar to bench bleeding the slave, in case you didn't do that before the installation.

HYDRAULIC SYSTEM BLEEDING This operation must be performed any time the clutch master or slave cylinder has been removed or if any of the hydraulic lines have been opened.

WARNING Do not spill brake fluid on the bodywork of the vehicle; it will destroy the paint. If fluid is spilled, immediately wash the surface with plenty of clean water.

1. Fill the master cylinder reservoir with brake fluid.
2. Remove the cap on the bleeder screw on the clutch slave cylinder. Install a clear vinyl hose on the fitting; place the other end submerged in a clear glass jar partially filled with brake fluid.
3. Have an assistant pump the clutch pedal slowly several times. After several pumps, hold the pedal down and open the bleeder, allowing fluid to flow into the jar. Close the bleeder valve almost immediately after opening it. Release the pedal only after the bleeder is closed.
4. Repeat the process until the fluid in the hose contains no air bubbles. tube. When there are no more air bubbles in the system, tighten the plug fully with the pedal depressed. Replace the plastic cap.
5. Fill the clutch master cylinder reservoir to the correct level with brake fluid.
6. Check the system for leaks.

Sounds like it's probably the Master Cylinder. If it is and you change it, it is a good idea to go ahead and change the slaves as well.

http://www.autopartswarehouse.com/search/?searchType=global&N=0&Ntt=Clutch+master+For+85+Supra&submit=

http://www.autopartswarehouse.com/search/?searchType=global&N=0&Ntt=clutch+slave+for+85+supra&submit=

Hope this helps.

I believe you have a hydraulic clutch. You may be low on fluid in the master cylinder for the clutch. If it is low, it takes regular DOT3 brake fluid. After you fill it, you might have to drive it a day or two for it to recover.

Yes, your clutch might be worn and/or out of adjustment or the trans is worn. Your clutch may be fine also. Toyota's have a problem with there shifter bushings and seats. They brake and crack also causing shifting problems. And some times only one gear depending on the condition.If yours is broken,crack or damaged, you can find the parts from Toyota and there a whole lot cheaper than a clutch. Also I recommend adjusting the clutch if possible. Not all are adjustable. Check your clutch fluid.

you need to bleed the clutch system.. have someone pump the clutch pedal three or four times, hold it down and release the bleeder valve( make sure the person holds the pedal down till after you tighten the bleeder valve back down) repeat this four or five times or till the clutch pedal feels like it did before.. good luck keith...

Replace the clutch master and slave cylinders.
I recently had the exact same problem on my car.

you need to fill your brake fluid resevoir to the fill line and your brake light on the dash will go away