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Business Hours

Mon - Fri 8:00 AM - 4:30 PM
 ( Central)
 

All Prior products are proudly made in the U.S.A.

Caution!

 

Installation Instructions

  1. Carefully remove the old unit from the vehicle by disconnecting the hydraulic lines, brackets and connections to the pedal. Place the old core in box of the replacement unit, and return it to the store for your core credit.

  2. Attach all mounting brackets and fittings from the old unit on the replacement unit. Install on your vehicle in the same position as the old unit was removed. Re-connect the hydraulic brake lines.

  3. Do not remove any nut that is holding a cylinder or face plate to install a bracket. You should install the bracket over the present nuts and secure with new nuts.

  4. Do not plug or bypass any hydraulic port on the unit. This could substantially reduce the brake performance.

  5. Warning: Brake bleeding instructions included must be followed. Failure to follow this procedure will result in inefficient braking performance.

Note:  LOCATE AND ELIMINATE THE CAUSE OF FAILURE BEFORE INSTALLING REPLACEMENT UNIT!

Dirt, sand or foreign material in the brake system is responsible for most failures of original equipment units, and is a major cause of early failure in replacement units. All old brake fluid should be flushed from the system. On remote mounted boosters (units mounted underneath truck on frame) the master cylinder on the firewall should be rebuilt and thoroughly cleaned, making sure that all sludge and dirt are removed from the reservoir. If the old unit is not cleaned properly, the dirt will be forced down into the booster during the first application of the brakes.

Gasoline and oil contamination are also major causes of early failure in power brake units. If the vacuum hose runs directly from the engine down to the booster, gasoline could enter the unit and destroy the rubber diaphragm. (See "Caution Gasoline Danger" app. note.)

Special note: A major portion of all warranty returns are the result of IMPROPER BLEEDING (not removing all of the air bubbles from the hydraulic system), and IMPROPER BRAKE SHOE ADJUSTMENT.

TESTING POWER BRAKE ON VEHICLE

  1. With the engine off, press the brake pedal several times to deplete all vacuum reserve in system

  2. Press the brake pedal and hold light foot pressure on the pedal. Start the vehicle engine. If power brake is operating pedal will fall away under foot pressure and less pressure is required to hold the pedal in the applied position. If no action is felt when the engine is started, the power brake is not functioning.

  3. Stop the engine. Again, deplete all reserve in the vacuum system. Press the brake pedal and hold foot pressure on the pedal. If the pedal gradually falls away under foot pressure, the hydraulic system is leaking.

  4. If the brake pedal travels to within 1" of the floorboard, brake shoes  require adjustment.

  5. Start the engine and run to medium speed, the turn off ignition. Immediately close throttle to build up vacuum. Wait at least 90 seconds and then try brake action. Two or more applications should be vacuum assisted. If not, vacuum check valve is faulty or there is a leak in the vacuum system.

Warning

DO NOT RELEASE A VEHICLE UNTIL A FIRM BRAKE PEDAL IS OBTAINED

Road test the vehicle in a safe area by applying the brakes while traveling about 20 mph to determine if the vehicle stops evenly and quickly. If the pedal has a spongy feel, hydraulic system may contain air. Bleed the system thoroughly to remove all air. (See "Troubleshooting Guide app note.)

 


 

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Prior Brake Products Inc., P.O. Box 462167, 315 So. International Rd. Garland, TX 75042
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Copyright 1999 - 2006 Prior Brake Products, Last modified:
Friday, October 06, 2006