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proper steps to bleed brakes on 1994 pontiac sunbird

With or without ABS ?

With or without ABS ?

with ABS

with ABS

in most cases just a

in most cases just a regulator bleed will do, if abs module went dry, bleed, disconnect batt. and drive, do this a few times.

ectorlopez48, BLEEDING ABS-VI



The Delco VI system is a non integral ABS system with conventional master brake cylinder and power booster. There are four wheel-speed sensors, functioning within a three-channel system. The front brakes are controlled separately, and the rear brakes share a common ABS circuit. You’ll find that the hydraulic modulator and motor pack are attached to the master cylinder. The modulator is held in place via two banjo bolts at the master cylinder. There are two upper outlet ports, and two transfer tubes located at both lower outlet ports.


Both the lower transfer tubes and O-rings must be replaced if the master cylinder and the modulator are disconnected from each other. Omitting this step or ignoring it, will cause fluid leaks and brake failure. There are fluid chambers within modulator assembly for all four brakes.


Two isolation solenoid valves
4 check balls
A motor pack containing three bidirectional direct current motors with electromagnetic brakes and/or expansion spring brakes

Three ball screw assemblies,
Four pistons,
A gear drive set and gear cover.


The modulator motor pack
Isolation solenoid valves
Gear cover
Individual gears

Are all serviceable parts that can be replaced separately.

Delco ABS-VI can be bled using manual, vacuum or pressure bleeding. The bleeding sequence is right rear, left rear, right front, left front. Before you begin, you must be sure that the rear pistons in the modulator are in the home position so that the check balls are unseated. If this step is not done or omitted you won't be able to bleed the rear brakes.


One is with a tech one scan tool or similar tool. Select F4 ABS Test mode, then select F0 manual control option. At this point, you can command the rear motor to drive the pistons to the home position.

Without a scan tool, you have to open the front bleeder screw at the modulator. There are two screws, so you have to be sure you are opening the forward most screw. Now bleed the modulator. Now close the screw, and bleed both front brakes starting with the right side first. Confirm a firm pedal. Drive the car at 5 mph. At this point the controller will automatically reset the system by sending a command to the rear motor to run the home position. At this point you can bleed the rear brakes.

Manual Bleeding Remove

Manual Bleeding

Remove master cylinder reservoir cover, then fill reservoir as necessary.
Attach one end of a clear plastic hose to rear bleeder valve of the brake control assembly, then put opposite end of the hose into a clean container.
While depressing brake pedal, slowly open bleeder valve, until fluid begins to flow.
Close valve and release brake pedal, then repeat procedure for front bleeder valve.
Ensure master cylinder is full, then raise and support vehicle.
Bleed wheel cylinders and calipers using the following sequence:
Right rear.
Left rear.
Right front.
Left front.
Lower vehicle and check fluid level in reservoir, fill as necessary.
Turn on ignition and note pedal travel and feel as follows:
If pedal feels firm and constant, start the engine and recheck pedal travel. If pedal still feels firm and constant, continue procedure.
If pedal feels soft or has excessive travel either initially or after engine is started, repeat bleeding procedure.
Road test vehicle, make several normal stops from a moderate speed, then make one or two ABS stops at approximately 50 mph.
Ensure pedal is still firm and constant.