Brake Bleeding question
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Brake Bleeding question
Hi guys. My car has been sitting for about the last year or so and has only periodically been started. Last time I drove it, it has the abs failure light and the pedal has very little pressure.
I checked the brake master cylinder resivoir and it was way low on fluid. I topped it off and then I proceeded to bleed the 4 corners (thank god for speed bleeders!).
Other than that, should I bleed the abs system? If so, how do I do that? Thanks in advance!
Also, I'm going to fire up the car in the morning and I'll be able to advise if the pedal feel is better and the lights are gone.
I checked the brake master cylinder resivoir and it was way low on fluid. I topped it off and then I proceeded to bleed the 4 corners (thank god for speed bleeders!).
Other than that, should I bleed the abs system? If so, how do I do that? Thanks in advance!
Also, I'm going to fire up the car in the morning and I'll be able to advise if the pedal feel is better and the lights are gone.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
You don't "bleed" the abs. ABS is part of the brake system, inline, so what you do to bleed the calipers is also working to purge air from the ABS lines.
The only time you should have to do an extensive bleed is when/if the entire system has been drained or lines have been drained that come off the ABS block. You WILL have to pump the pedal a couple times to build pressure IF there has been air pushed into the lines. IF it does not stiffen up, simply bleed again and it will get better. Might take a couple tries depending on how much air got in the master from empty cup(s).
When bleeding, KEEP bleeding until you get a firm pedal. With speed bleeders, pump for awhile, tighten the screw, try the pedal. If its still soft, bleed some more.
The big question is....where did the fluid go?
The only time you should have to do an extensive bleed is when/if the entire system has been drained or lines have been drained that come off the ABS block. You WILL have to pump the pedal a couple times to build pressure IF there has been air pushed into the lines. IF it does not stiffen up, simply bleed again and it will get better. Might take a couple tries depending on how much air got in the master from empty cup(s).
When bleeding, KEEP bleeding until you get a firm pedal. With speed bleeders, pump for awhile, tighten the screw, try the pedal. If its still soft, bleed some more.
The big question is....where did the fluid go?
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
You need to state the year of your Corvette...because I can not assume what you have listed is correct on your information...or if it another Corvette.
Unless the master cylinder reservoir ran DRY...no air got into the system and you are fine.
ABS light is separate from the hydraulic system. The ABS unit enhances the hydraulic sytem and if working correctly it will prevent the wheels from locking up in a panic stop. If you start the car and either back up or go forward and reach 5+MPH...you should hear the ABS unit behind your seat energize. If you do not...chances are the pump is bad and will cause this light to come on. Even a bad ABS unit will still allow the brakes to function...except they can now lock-up and skid...instead of pulse as designed. Or you have bad or dirty sensors at the wheels..which can cause the light also...along with many other times. The two I listed are the most common I encounter at my shop.
DUB
Unless the master cylinder reservoir ran DRY...no air got into the system and you are fine.
ABS light is separate from the hydraulic system. The ABS unit enhances the hydraulic sytem and if working correctly it will prevent the wheels from locking up in a panic stop. If you start the car and either back up or go forward and reach 5+MPH...you should hear the ABS unit behind your seat energize. If you do not...chances are the pump is bad and will cause this light to come on. Even a bad ABS unit will still allow the brakes to function...except they can now lock-up and skid...instead of pulse as designed. Or you have bad or dirty sensors at the wheels..which can cause the light also...along with many other times. The two I listed are the most common I encounter at my shop.
DUB
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
No clue where it went. The car was sitting in the driveway for the last year. I just topped off the fluid and now it's in the garage, so I should be be able to find out where it's leaking. The abs lights are now off. The pedal is still soft so I have some more bleeding to do.
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
If the car hasn't been driven too much since the light was on there should be a history code stored to point as to why the ABS light was on in the first place. It will come on in addition to the brake warning lamp if the MC res is low. IIRC the ASR will light up too for that one.
So read the codes using the paperclip method and post them along with their module number.
So read the codes using the paperclip method and post them along with their module number.
