1991 Oldsmobile Cutlass Supreme Brake Service (ONLINE REPAIR MANUALS)

DESCRIPTION

This unit utilizes a vacuum power chamber, consisting of a front and rear shell, housing divider, front and rear diaphragm, plate assemblies, hydraulic pushrod and a diaphragm return spring,Figs. and .

The unit operates in much the same manner as the single diaphragm unit described previously. The diaphragm and plate assemblies utilize the pressure differential between the engine intake manifold vacuum and atmospheric pressure to assist in braking.

TROUBLESHOOTING

Hard Pedal

• Internal vacuum leak.
• Faulty control valve.

Brakes Grab

• Faulty control valve...

During ABS operation, the Delco-Moraine ABS-III system cycles (pulses), the brakes, adjusting line pressures, to obtain optimum stopping distance and vehicle control. During this cycling, the brake pedal will pulsate and clicking noises will be heard from the solenoids as they control the cycling. Clicking of the solenoids and pulsating of the brake pedal at this time and during a short period after vehicle starting is normal.

During ABS braking, to optimize stopping distance, the ABS will pump the brake pedal. The driver shou...

The main components of the Delco-Moraine ABS-III, are the Powermaster III hydraulic booster/master cylinder, four wheel speed sensors, speed sensor rings, remote proportioner valve assembly and an anti-lock brake controller.

ANTI-LOCK BRAKE CONTROLLER

The anti-lock brake controller monitors the speed of each wheel to determine if a wheel is approaching lock-up. If this condition is detected, the controller pulses the appropriate solenoids in the Powermaster III, to adjust brake pressures. The controller also monitors the system for malfunctions, provides diagnostic information a...

DESCRIPTION

This booster is a single diaphragm, vacuum suspended unit with a lightweight cast alloy housing,Fig. . Vacuum is applied to the front and rear housings. When the brake pedal is released, negative pressure is equalized on both sides of the diaphragm and power piston assembly. Spring tension holds the piston at the rest position. When the brakes are applied, the atmospheric port in the power piston is opened. Negative pressure in the front chamber pulls the diaphragm and vacuum piston assembly, reaction disc and output rod forward. Pressure on the master c...

Should it become necessary to remove the caliper for installation of new parts, clean all parts in alcohol, wipe dry using lint free cloths, using an air hose to blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly.

Inspect piston bores for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the...

When working on or around brake assemblies, care must be taken to prevent breathing asbestos dust, as many manufacturers incorporate asbestos fibers in the production of brake linings. During routine service operations the amount of asbestos dust from brake lining wear is at a low level due to a chemical breakdown during use, and a few precautions will minimize exposure.

• Do not sand or grind brake linings unless suitable local exhaust ventilation equipment is used to prevent excessive asbestos exposure.
• Wear a suitable respirator approved for asbestos dust use during all repai...