bleeding the abs
07-05-2007, 12:55 PM
#3
From my Hayes:
It is mounted in the left front corner of the engine compartment. Mine has a bleeder screw on it. Just bleed it like any normal brake, the old press and hold the pedal, open the screw, let the air out, close the screw. Repeat until no more air comes out.
It is mounted in the left front corner of the engine compartment. Mine has a bleeder screw on it. Just bleed it like any normal brake, the old press and hold the pedal, open the screw, let the air out, close the screw. Repeat until no more air comes out.
07-05-2007, 01:14 PM
#5
TECH Junkie
iTrader: (7)
Join Date: Jul 2005
Location: MA
Posts: 3,934
Likes: 0
Received 0 Likes
on
0 Posts
I'm pretty sure the LS1s don't have anything you can use to bleed the ABS system from outside the car. I'm pretty sure its just for LT1s but I am not completely sure. It could be a certain set of years of the LT1s...
Trending Topics
07-06-2007, 10:03 PM
#8
i have the 2002 gm service manual,
you do not *need* to bleed the abs modulator, what they call BPMV (brake pulse modulator valve) in the book. It's the square chunk of aluminum drivers side engine bay with all the brake hardlines coming out of it.
They make reference to: if the desired brake pedal height is not achieved from bleeding the brake system at the calipers (implying you have no air in the lines or calipers) then there is an automated procedure for cycling the valves and running the abs pump in order to purge air from it and secondary circuits normally closed off during normal brake operation and bleeding.
I think this is only relevant if there's a chance you introduced air in that part of the system, which is highly unlikely unless you ran the master cylinder empty then filled it to bleed the system. Then you would have pushed air into the BPMV. Or if you removed the bpmv or any lines coming off it of course.
To bleed the BPVM or abs unit, you need a scan tool and there's supposed to be an auto bleed procedure under the special functions menu. I'm sure the GM service manual is referring to a dealer GM specific scantool piece of equipment. It goes on to say follow scan tool directions until desired brake pedal height is achieved.
all that said, just bleed the system at the calipers keeping the master cyl resevoir from going empty. if the pedal height is way low or is still soft and brakes don't operate right then look into running the auto bleed program via a scantool for the abs unit. hope this helps.
you do not *need* to bleed the abs modulator, what they call BPMV (brake pulse modulator valve) in the book. It's the square chunk of aluminum drivers side engine bay with all the brake hardlines coming out of it.
They make reference to: if the desired brake pedal height is not achieved from bleeding the brake system at the calipers (implying you have no air in the lines or calipers) then there is an automated procedure for cycling the valves and running the abs pump in order to purge air from it and secondary circuits normally closed off during normal brake operation and bleeding.
I think this is only relevant if there's a chance you introduced air in that part of the system, which is highly unlikely unless you ran the master cylinder empty then filled it to bleed the system. Then you would have pushed air into the BPMV. Or if you removed the bpmv or any lines coming off it of course.
To bleed the BPVM or abs unit, you need a scan tool and there's supposed to be an auto bleed procedure under the special functions menu. I'm sure the GM service manual is referring to a dealer GM specific scantool piece of equipment. It goes on to say follow scan tool directions until desired brake pedal height is achieved.
all that said, just bleed the system at the calipers keeping the master cyl resevoir from going empty. if the pedal height is way low or is still soft and brakes don't operate right then look into running the auto bleed program via a scantool for the abs unit. hope this helps.
