Internally Mounted Slave Cylinder

Remove rubber plug from inspection port in transmission bellhousing. Position Bearing Travel Measurement Tool (D87T-4201-A) through opening and against slave cylinder. See Fig 1 .
Using rear edge of Black plastic bearing retainer as an indicator, take a reading with clutch pedal fully up. With clutch pedal fully depressed, take another measurement.
Difference between 2 readings is total bearing travel. If bearing travel is greater than 0.3" (7.5 mm), replace clutch pressure plate and/or clutch disc.
If bearing travel is less than 0.3" (7.5 mm), check hydraulic reservoir fluid level and inspect hydraulic system for leaks.
If leak is found, repair leak and bleed system. If no leak is found, bleed system. See HYDRAULIC SYSTEM BLEEDING under IN-VEHICLE SERVICE. Recheck bearing travel after repairs have been completed.

Fig 1: Measuring Clutch Release Bearing Travel

Courtesy of FORD MOTOR CO.