05 Equinox brake question, any GM techs here? - Chevy Colorado & GMC Canyon

ColoradoFans.com is the premier Colorado Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 01-20-2012, 07:09 AM   #1 (permalink)
Senior Member
 
Gilly's Avatar
 
Join Date: Mar 2005
Location: Evansville WI
Posts: 578
Default 05 Equinox brake question, any GM techs here?

Just thought I would ask, I know this is supposed to be a Colorado forum. My sisters Equinox, 1st year 2005, same year as my Colorado, just as you come to a stop the ABS pump runs, makes the buzzing noise, but does stop OK, so just an irritation sort of thing. Doesn't have any kind of warning light for the ABS. Doesn't do it every time she stops, but will do it on dry pavement.
Gilly
Gilly is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 01-20-2012, 11:27 AM   #2 (permalink)
Senior Member
 
08Canyon's Avatar
 
Join Date: Oct 2011
Posts: 5,514
Default

It sounds like there is something faulty with a speed sensor if ABS is kicking in. When the wheel stops rotating the ABS system becomes energized. It sounds like the system think the wheel has quit rotating. Has the vehicle been in an accident or had any repair work performed lately?
08Canyon is offline   Reply With Quote Quick reply to this message
Old 01-20-2012, 05:52 PM   #3 (permalink)
Senior Member
 
Gilly's Avatar
 
Join Date: Mar 2005
Location: Evansville WI
Posts: 578
Default

Only thing I am aware of is she needed the engine replaced, put in a used engine IIRC. I wonder if a rear brake could be grabbing? Like I say though, it seems to stop fine otherwise.
Yeah I figured that the ABS thinks a wheel is locking so is applying abs. I sort of thought if a sensor was bad that it would throw a code, why would it fail like this only when coming to a stop?
I will wait and see what kind of feedback I get from her since I did the front brakes. I did tell my feelings about it after I did the front brakes and then noticed this problem, so maybe just knowing what it is will make her happy enough. If it was mine I'd want it fixed though. Too bad it all has to happen just when we get this crappy weather though.
Gilly is offline   Reply With Quote Quick reply to this message
Old 01-20-2012, 06:49 PM   #4 (permalink)
Senior Member
 
08Canyon's Avatar
 
Join Date: Oct 2011
Posts: 5,514
Default

I don't know if a code would be thrown for ABS, because it's doing the job it's supposed to do. If anything, I would expect a brake light would illuminate on the dash if there was fault in the brake system.

It should only fail during stopping because that is when the ABS system is being energized. Honestly, I don't have any other ideas.

When you did the front brakes, did you damage the ABS line, or have any reason to remove the rotor? The ABS ring may not be seated properly if you have removed the rotor.

I think you would feel it if the rear was locking up, it should be pretty grabby if one of the brakes are out of adjustment. Are the rear brakes drums or disc? Drums, maybe you can try readjusting the shoes in the drums.
08Canyon is offline   Reply With Quote Quick reply to this message
Old 01-21-2012, 02:05 PM   #5 (permalink)
Senior Member
 
Gilly's Avatar
 
Join Date: Mar 2005
Location: Evansville WI
Posts: 578
Default

The wheel speeds are being monitored at all times I believe, not just when the brakes are applied. So I would assume, if a sensor was bad and went down to "zero" rpms while driving, that there would be a code. It would be hard to believe that the sensor is failing only when almost stopped and causing the pump to run. That's why I am confused. Even the reluctor ring, if that were the problem, I would think would cause a code of some sort. Unless it's only a problem that the reluctor ring is plugged up that only bothers at low rpm.

The problem I am assuming was before I replaced the front brakes. I did a road test and looked at the pads and rotors a few days before i replaced the front brakes. They complained about "a noise" which I never heard. Or at least i don't remember hearing the pump running on that road test. But now it's doing it. I did explain to them what the noise is (they're not very mechanically inclined. Also not sensitive to the fact that it's a lot more effort to do this crap in the middle of winter, they just don't get ithat I guess. I tried getting them to have me do this work around Christmas when we were still in "Global Warming mode" up here).

The rear brakes are drums.

I don't really feel anything abnormal as far as pulling one side or the other, either before the pump runs or on the stops I do where the pump isn't running, feels fine. I am not concerned about the safety aspect at all, this seems like just an annoyance.
Gilly is offline   Reply With Quote Quick reply to this message
Old 01-21-2012, 06:19 PM   #6 (permalink)
Senior Member
 
Join Date: Nov 2009
Location: Hamilton, Ontario
Posts: 131
Default

This is common to just about any GM vehicle its called sensor drop out. As the wheel speed comes almost to a stop a sensor will drop out and give the ABS computer a false lockup. I am a technician and this is almost a daily thing. I've had good luck by going for a drive with the scan tool attached with all 4 sensors in a graph start recording and drive around the block. If you feel the ABS kick on you will see one of the graphs fall to zero thats your sensor that will need to be replaced. Its built into the hub so they do cost a bit to replace.
Oscar-mayer is offline   Reply With Quote Quick reply to this message
Old 01-24-2012, 07:43 PM   #7 (permalink)
Senior Member
 
Gilly's Avatar
 
Join Date: Mar 2005
Location: Evansville WI
Posts: 578
Default

Thanks, will keep it in mind. I was also reading something about the reluctor rings like to crack, they are out on the end of the CV joint? I guess will cause a problem. I wonder, since i am not a tech anymore, if I took it to autozone if they'd let me do that road test with their scanner? I know you probably don't know, but thinking out loud.
Gilly
Gilly is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy Colorado & GMC Canyon forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 06:25 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0