Bleeding just the accumulator on the brake booster?

[Eicca]

Replaced the brake booster on my parents' 1999. Found a used part. Install went fine, line bleed went fine. Nothing leaks.

However, about once a week the ABS light will stay on for an additional 10-20 seconds after the vehicle is started. This seems to indicate the system losing excess pressure when sitting or not building fast enough when first started up.

The module was entirely empty of fluid when I got it, so I imagine some air got in somewhere. Is it possible to bleed just the accumulator part of the circuit?

 

[medtro]

May be get the error code to narrow down which sensor triggers the ABS light.

 

[nukegoat]

Replaced the brake booster on my parents' 1999. Found a used part. Install went fine, line bleed went fine. Nothing leaks.

However, about once a week the ABS light will stay on for an additional 10-20 seconds after the vehicle is started. This seems to indicate the system losing excess pressure when sitting or not building fast enough when first started up.

The module was entirely empty of fluid when I got it, so I imagine some air got in somewhere. Is it possible to bleed just the accumulator part of the circuit?

The accumulator is supposed to have gas in it

 

[2001LC]

If accumulator has air in it, it more or less bleeds into reservoir. By pumping brake pedal 40 times, IG key OFF, then set level in reservoir. Important too check voltage with a meter. At 12.7 volt. A new booster assembly (which includes motor). Will charge (IG key on, time booster motor run time) accumulator with brake fluid in about 28 to 30 seconds. If you run much over that, I would bleed lines again. If over 40 seconds, FSM does state re-bleed. But before bleed. Go out on a dirt road at 30 MPH or greater, stomp on brake hard holding on. Do this 3 times. Each time you should hear the crunch of ABS activating.

Also inspect for brake fluid leaks, end to end.

If at any time you hear brake master squealing, and see bubbles coming up from of reservoir. Count on replacing the master.

 

[Eicca]

Seems like any air in the accumulator has bled out. The problem disappeared and everything is still working great.