Ford F-150 pickups with the 4.9-liter inline six-cylinder engine used a hydraulic clutch system from 1987 through 1996, when the 4.9-liter engine was phased out in favor of the 4.2-liter V-6 engine. Earlier models used a mechanical clutch linkage. The 1987 F-150 uses an external slave cylinder. The 1988 through 1996 models use an internal slave cylinder. The master cylinder is bled through the slave cylinders. The procedures are different for each one.
Park the F-150 on a level, paved surface and set the parking brake. Raise the front of the F-150 and support it with jack stands.
Don a pair of safety glasses. Move under the transmission and locate the slave cylinder on the side of the bell housing. Slide a drain pan under the slave cylinder. Use a 3/32-inch punch and hammer to tap out the pin that holds the hydraulic line onto the slave cylinder. Remove the line from the slave cylinder. Allow it to hang over the drain pan.
Pull the retaining clip from the slave cylinder bracket. Pull the slave cylinder from the bracket. Tip the cylinder so the hole where the hydraulic line fits is at the highest point. Slowly pour fresh DOT 3 brake fluid into the cylinder until it is full. Rock the cylinder and apply a little pressure to the push rod to make sure there is no air in it.
Wipe the cylinder off with a shop rag. Mount the cylinder in the bracket and install the clip.
Instruct an assistant to remove the cap from the master cylinder and fill the reservoir with fresh brake fluid. Fluid will begin to flow from the end of the hydraulic line; catch it in the drain pan.
Watch the flow of fluid. Some air bubbles should come out at first. Allow the fluid to flow until you see no air bubbles. Tell your assistant to replace the cap on the master cylinder to stop the fluid flow. Install the hydraulic line into the slave cylinder and install the pin. Use the punch and hammer to tap it into place.
Raise the F-150, remove the jack stands and lower it to the ground. Make sure the master cylinder is full.
Wearing safety glasses, move under the transmission and locate the slave cylinder on the side of the bellhousing. The bleeder fitting is located just below the hydraulic line.
Top off the master cylinder reservoir. Tell your assistant to push the clutch pedal to the floor and quickly release it. Wait for two seconds and repeat. Repeat nine more times. Check and fill the master cylinder if needed. Repeat the whole process five times.
Tell your assistant to push the pedal down and hold it there. Move to the bleeder. Hold a shop rag near the bleeder. Use a box-end wrench to open the bleeder just far enough to allow any air to escape. Catch any brake fluid with the shop rag. Close the bleeder and tell your assistant to let up on the pedal. Repeat this process until no air escapes from the bleeder.
Raise the F-150, remove the jack stands and lower it to the ground. Make sure the master cylinder is full.
