Transmission will not shift when hot. This typically occurs in stop and go traffic and on hot days the symptoms appear much quicker than on cold days. Clutch pedal is all the way to the floor. My sense is the hydrolic systems is weak or the pedal/pressure needs to be adjusted to increase pressure in the hydrolic lines so the shifting can occur seamlessly. Syncros work, no grinding. All new hydrolic fluid.
Your clutch master cylinder is worn out.
Along with the master, you should also replace the slave cylinder.
Thank you. Any idea on cost?
Labor costs vary considerably around the country.
If you are lucky, you might be able to have the work done for around $300.00-$350.00