Asking about this for a friends vehicle.
Trying to fix a brake issue on an 09 Pontiac Torrent (basically a 1st gen Equinox) and I cannot figure it out, i worked on this sort of thing at GM for years and am totally stumped. Ive driven it for a bit and the brakes work fine, the vehicle stops fine - but there is an intermittent front end shake (like a light rotor warp) under heavy braking, and in all conditions there is a low whine that comes from the brake master cylinder area when the car is coming to a stop (1-2 MPH), then goes away once the vehicle comes to a stop for a second or two. You can feel it in the petal when it whines, but there is not loss of braking power or petal pressure such as the booster bleeding or there is not enough fluid in the reservior. The car IS from up north (spent 3+ years in Ohio) so Im thinking rust or corrosion might be a part of the issue here, Im completely unfamiliar with what can happen to a brake system when that is the issue (im used to working on southern cars only) - that is why Im asking you guys here. Ive asked a buddy that I used to work with at GM and he cant figure it out from the description either, just seeing if any of you northern guys can maybe help me out or atleast tell me where to look. I dont wanna just go throw the master cylinder or ABS module and it unless i know thats the issue, thanks for the help.
Trying to fix a brake issue on an 09 Pontiac Torrent (basically a 1st gen Equinox) and I cannot figure it out, i worked on this sort of thing at GM for years and am totally stumped. Ive driven it for a bit and the brakes work fine, the vehicle stops fine - but there is an intermittent front end shake (like a light rotor warp) under heavy braking, and in all conditions there is a low whine that comes from the brake master cylinder area when the car is coming to a stop (1-2 MPH), then goes away once the vehicle comes to a stop for a second or two. You can feel it in the petal when it whines, but there is not loss of braking power or petal pressure such as the booster bleeding or there is not enough fluid in the reservior. The car IS from up north (spent 3+ years in Ohio) so Im thinking rust or corrosion might be a part of the issue here, Im completely unfamiliar with what can happen to a brake system when that is the issue (im used to working on southern cars only) - that is why Im asking you guys here. Ive asked a buddy that I used to work with at GM and he cant figure it out from the description either, just seeing if any of you northern guys can maybe help me out or atleast tell me where to look. I dont wanna just go throw the master cylinder or ABS module and it unless i know thats the issue, thanks for the help.