Ranger 2WD V6-245 4.0L (1990)
Removing Snap Ring
2. Depress the primary piston and remove snap ring from retaining groove at the rear of the master cylinder bore.
3. Remove primary piston assembly from the master cylinder bore and inspect for seal damage or twisting.
4. Remove the secondary piston assembly by directing compressed air into the outlet port at the blind end of the bore while plugging the other outlet
port. Inspect for seal damage or twisting.
5. Inspect the master cylinder bore for signs of etching, pitting, scoring or other damage.
a. If bore is damaged, discard and replace with new master cylinder assembly. Do not attempt to hone bore.
b. If bore is not damaged, rebuild master cylinder assembly using the proper repair kit and the procedure outlined below.
ASSEMBLY
1. Clean the master cylinder body with clean isopropyl alcohol or brake parts cleaner to remove any contamination.
2. Dip the repair kit piston assemblies in clean Dot 3 brake fluid to lubricate seals.
3. Carefully insert the complete secondary piston assembly in the master cylinder bore.
4. Carefully insert the primary piston assembly in the master cylinder bore.
5. Depress the primary piston and install the snap ring in the cylinder bore groove.
6. On vehicles with manual brakes, install the push rod retainer onto the push rod and install into the primary piston. Make sure the retainer is
properly seated and holding the push rod securely.
7. Install the cap and diaphragm on the master cylinder reservoir.
