W 350 Pickup V8-360 5.9L VIN W (1984)
Brake Caliper: Service and Repair
Disassembly and Assembly
Disassembly
CAUTION: Under no condition should air pressure be used to remove piston from bore. Personal injury could result from such a practice.
Caliper-Piston Removal
1. Raise vehicle and support on hoist or jack stands. Remove wheel and tire assembly.
2. Clean brake hose and tubing connections at caliper and brake line.
3. Remove caliper from adaptor and brake shoes from caliper and adaptor.
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Do not disconnect hydraulic brake hose from brake line or caliper.
4. Support caliper on front axle assembly on shop towels to absorb any hydraulic fluid loss.
5. Carefully depress brake pedal to hydraulically push piston out of bore.
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Brake pedal will fall away when piston has passed cylinder bore opening.
6. Prop brake pedal to any position below the first inch of pedal travel to prevent loss of brake fluid.
If both front caliper pistons are to be removed:
a. Disconnect flexible brake hose at frame bracket after removing first piston.
b. Plug brake tube to remove piston from opposite caliper.
7. Disconnect brake flexible hose from caliper.
8. Remove boot from piston.
9. Using a small pointed wooden or plastic rod, carefully remove the piston seal from the caliper cylinder bore.
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Do not use a metal tool of any kind for this operation as it may damage the cylinder bore or burr the seal groove.
10. Discard seal and boot.
NOTE: Whenever the caliper is disassembled a new seal and boot must be used for reassembly.
Assembly
1. Clamp caliper in vise (with protector jaws).
CAUTION: Excessive vise pressure can cause bore distortion and binding of piston.
Fig 14 Installing Piston Seal
2. Lubricate the new piston seal with clean brake fluid and position the seal in the groove in the cylinder bore.
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Position seal in one area of groove and gently work around and into the groove until properly seated.
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Be sure seal is not twisted or rolled.
3. Coat new piston boot with brake fluid.
