BRAKE MASTER CYLINDER QUICK TAKE-UP VALVE SQUEAK

MODELS AFFECTED: 1981-1984 DEVILLES, BROUGHAMS, AND COMMERCIAL CHASSIS 1982-1984 CIMARRONS 1983-1984 ELDORADOS AND SEVILLES

Some 1981 through 1984 Cadillacs equipped with vacuum brake boosters may experience a whistle or squeal noise during repeat brake applications when the vehicle is either stopped or moving. This may be due to fluttering of the Quick-Take-Up Valve located in the master cylinder.

To diagnose this condition, use a stethoscope type instrument to isolate the source of the noise to the master cylinder reservoir mounting boss which contains the Quick-Take-Up Valve. While a fluid hiss is normal, a squeal or whistle is not.

To correct this condition, a Quick-Take-Up service kit has been developed to replace an original unit. The kit contains: (1) Quick-Take-Up Valve, (2) reservoir grommets, (1) retainer, and (1) instruction sheet.

QUICK-TAKE-UP VALVE KIT P/N MODEL USAGE --------------------------- ----------- 18011866 1981-1984 Devilles, Broughams, Commercial Chassis 1983-1984 Eldorado and Seville

18011899 1982-1984 Cimarron

QUICK-TAKE-UP VALVE KIT INSTALLATION

The following service procedures are to be performed with the master cylinder installed on the vehicle.

IMPORTANT: The following steps are to be performed with the master cylinder above 60 DEG F to avoid damage to the reservoir during removal.

1. Clean and remove reservoir cover.

2. Using a clean syringe (previously used only with brake fluid), remove and discard all brake fluid in the reservoir.

3. Place shop cloth under master cylinder. Reinstall reservoir cover. Grasp the reservoir at the base and rock the reservoir side to side, while pulling up, to remove reservoir from the master cylinder body. Be careful to catch excess brake fluid to avoid paint damage.

4. Remove and discard reservoir attaching grommets.

5. Carefully depress the Quick-Take-Up Valve retaining ring with a small screwdriver and pry retaining ring out (see Figure 1). Avoid gouging the aluminum master cylinder body or damaging the retaining ring groove. Remove and discard the retaining ring, retaining washer and Quick-Take-Up Valve. Inspect and clean the master cylinder body at the Quick-Take-Up port.

6. Lubricate the new Quick-Take-Up Valve with clean brake fluid and install as shown in Figure 1.

7. Install the new retainer ring provided by pressing directly on ring to assure positive seating.

8. Install new reservoir grommets into master cylinder at both locations. Lubricate grommets with clean brake fluid to aid reservoir assembly.

9. Place reservoir in grommets, press down and rock reservoir into position. Remove cover and fill reservoir with approved DOT 3 brake fluid (GM P/N 1052535 or equivalent). Replace cover and check brakes for pedal travel and brake warning light operation.

10. Bleed master cylinder and brake system as required.

For warranty purposes, use Operation T5075 at .5 hour.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.