Brake drag - not caliper or line - need help
#1
08-05-2015, 10:12 AM
Brake drag - not caliper or line - need help
Hi all - I am new to your forum. I have read many of the post related to the Saturn VUE XE 2WD brake drag and here is the issue:
I have 2008 VUE 2 WD. While driving the car starts to feel like it won't go (no power) and I smelled something hot. Also had a vibration from the front. Pulled over and the right front wheel was extremely hot. So hot it could not be touched at all and smelt burnt.
After cooling and suspecting a stuck brake - I backed up and tapped the brakes - this seemed to free the brake and I drove home with no problem.
After researching the problem on - line, I replaced the caliper, the caliper bracket, and the rubber brake hose and with the bracket - bled the lines and tried it again - same problem.
Now I am not sure what to do - can anyone help?
Could this be something other than the brakes?
If it is brakes - what is causing them to drag and how can I tell?
I have 2008 VUE 2 WD. While driving the car starts to feel like it won't go (no power) and I smelled something hot. Also had a vibration from the front. Pulled over and the right front wheel was extremely hot. So hot it could not be touched at all and smelt burnt.
After cooling and suspecting a stuck brake - I backed up and tapped the brakes - this seemed to free the brake and I drove home with no problem.
After researching the problem on - line, I replaced the caliper, the caliper bracket, and the rubber brake hose and with the bracket - bled the lines and tried it again - same problem.
Now I am not sure what to do - can anyone help?
Could this be something other than the brakes?
If it is brakes - what is causing them to drag and how can I tell?
#2
08-05-2015, 11:45 AM
Vibration sounds like a warped rotor.
If it is bad enough, it can rub on the pads even with the brakes not applied -- though it would need to be BAD, and the pads hanging up ever so slightly (tho not too much with new ones.)
If it did rub, it would create heat in the pad, which would heat up the rotor, which would heat up the pad>>>runaway heat >> everything swells together.
______
Do you still feel the vibration when braking after your caliper/etc swap? If so, I suspect the front right rotor to be the cause.
Replace BOTH the left and right rotors (you do them in pairs). Actually -- replace the right one first and see if the problem goes away (along with the vibration)
The intermittent nature of the problem seems wonky; does the problem only begin at high speed or low speed driving?
Only other think I can think of is guide or attachment pins insufficiently smooth and lubricated (or bent).
If the caliper piston was unable to retract, I'[d suspect a leak --but if you can wait the whole time it cooled down and tap the pedal, there's no way the caliper piston is at fault
If it is bad enough, it can rub on the pads even with the brakes not applied -- though it would need to be BAD, and the pads hanging up ever so slightly (tho not too much with new ones.)
If it did rub, it would create heat in the pad, which would heat up the rotor, which would heat up the pad>>>runaway heat >> everything swells together.
______
Do you still feel the vibration when braking after your caliper/etc swap? If so, I suspect the front right rotor to be the cause.
Replace BOTH the left and right rotors (you do them in pairs). Actually -- replace the right one first and see if the problem goes away (along with the vibration)
The intermittent nature of the problem seems wonky; does the problem only begin at high speed or low speed driving?
Only other think I can think of is guide or attachment pins insufficiently smooth and lubricated (or bent).
If the caliper piston was unable to retract, I'[d suspect a leak --but if you can wait the whole time it cooled down and tap the pedal, there's no way the caliper piston is at fault
#3
08-05-2015, 12:01 PM
Thanks for the quick reply.
I still feel the vibration - definitely feels like a warped rotor when braking.
When replacing the caliper - I noticed some "hot" spots on the rotor - parts store did not have one in stock - so I put the caliper assembly and brake line on and still have the problem.
I will replace the rotor and let you know what happens.
I still feel the vibration - definitely feels like a warped rotor when braking.
When replacing the caliper - I noticed some "hot" spots on the rotor - parts store did not have one in stock - so I put the caliper assembly and brake line on and still have the problem.
I will replace the rotor and let you know what happens.
#4
08-05-2015, 12:24 PM
I'm in agreement with derf on this one. Once a rotor gets that frigging hot, it's most likely going to warp. I'd go ahead and replace the caliper guide pins too, as they don't cost that much. Make sure to lubricate them with the proper lube from the parts store. Since you replaced the caliper and hose, I don't see what else it could be.
#8
08-06-2015, 03:50 AM
Unless the traction control or ABS lights are on on the dash, I'd say no. Plus you'd hear your ABS chattering and if it really thought it needed to stop that wheel completely, it would. You haven't mentioned any chattering or flashing (active system) ABS lights. So no, I don't think it's involved.
Last edited by derf; 02-26-2017 at 01:07 AM.
#9
08-12-2015, 08:48 AM
Update - so I installed a new rotor on the wheel giving me a problem. The issue is still there and "seems" worse. The overall symptoms are: after driving about 15 minutes or so, the car seems as if it has no power, then I can smell the hot wheel. If I back up and tap the brakes - it gets better to allow me to drive home. To date, that wheel has new caliper, new bracket and pins, new rotor, and new brake hose. Something is not letting the caliper release the pressure. What is left to check? I assume the only components left are the booster and master cylinder. Any ideas on what else to check?
#10
08-12-2015, 02:45 PM
The new rotor is full thickness(full spec). so the problem appears sooner....arrrgghh
You can put the older one back on rather than heat the brand new one up and warp it. My opinion anyway.
In theory, you may have a partial plug/restriction in that one brake line--the portion running from the master cylinder to the flex hose by that wheel---or a bunch of crap throughout the line that keeps intermittently restricting the flow of fluid, especially in the reverse direction (under negative pressure which should retract the piston in the caliper.) Or it could be a bad seal at the master cylinder such that there is no negative pressure building up when you release the brakes--hence the piston stays put. But then you
If it were the booster, you'd likely have a hard time stopping the car, period. Like driving with manual brakes.
IIRC, today's master cylinders are designed with a diagonal Front/Rear fluid routing configuration so that if the seal on either chamber fails, you always have one front and one rear wheel to stop the car.
If the master cyl seal for that frt/rear combo was bad, you should be having identical problems with the wheel diagonally to the rear of the front causing you the problem.
Your tap on the brakes applies additional POSITIVE pressure to the caliper, which probably dislodges stuff enough to retract far enough that the pads are no longer in contact w the rotor.
My guess is
1)crud in the line to the front wheel and/or corrosion in that line, producing crud.
2)Old brake fluid which has adsorbed water, is compressible and you do not want water in the system. The fluid may be significantly degraded such that the fluid mixture in the lines is actually boiling and forming steam.
a) Did you bleed the entire system or just at that one caliper?
b)How many miles were on the brake fluid when you started having this problem?
c)What came out when you bled the system the very first time after replacing the caliper? What color, were there particulates, etc
d) did you use a brand new unopened brake fluid container to add new brake fluid?
Recommendation:
a)flush the entire system with brand new unopened brake fluid.
b) replace the line from the master to the flex hose at the problem wheel.
c) bleed the entire system in the order specified for the vehicle.
To quote Rube, I am NOT a mechanic, The above represents my best attempt at analyzing your problem and recommending a solution. Use at your own risk. I do my best not to encourage people to spend money on things that will not fix the issue. And, as demonstrated to date, neither of us "shotgun" parts, as that does nothing but leave you with less money and a bunch of parts that do not necessarily have anything to do w solving the problem.
If there are holes in my analysis, I welcome all constructive criticism as it only helps everyone learn how the system DOES work and where my assumptions went wrong.
PLEASE, forum folks, read the above and see if I took a wrong turn somewhere. Brake lines are not cheap, and junkyard ones are likely to be corroded internally as well...
You can put the older one back on rather than heat the brand new one up and warp it. My opinion anyway.
In theory, you may have a partial plug/restriction in that one brake line--the portion running from the master cylinder to the flex hose by that wheel---or a bunch of crap throughout the line that keeps intermittently restricting the flow of fluid, especially in the reverse direction (under negative pressure which should retract the piston in the caliper.) Or it could be a bad seal at the master cylinder such that there is no negative pressure building up when you release the brakes--hence the piston stays put. But then you
If it were the booster, you'd likely have a hard time stopping the car, period. Like driving with manual brakes.
IIRC, today's master cylinders are designed with a diagonal Front/Rear fluid routing configuration so that if the seal on either chamber fails, you always have one front and one rear wheel to stop the car.
If the master cyl seal for that frt/rear combo was bad, you should be having identical problems with the wheel diagonally to the rear of the front causing you the problem.
Your tap on the brakes applies additional POSITIVE pressure to the caliper, which probably dislodges stuff enough to retract far enough that the pads are no longer in contact w the rotor.
My guess is
1)crud in the line to the front wheel and/or corrosion in that line, producing crud.
2)Old brake fluid which has adsorbed water, is compressible and you do not want water in the system. The fluid may be significantly degraded such that the fluid mixture in the lines is actually boiling and forming steam.
a) Did you bleed the entire system or just at that one caliper?
b)How many miles were on the brake fluid when you started having this problem?
c)What came out when you bled the system the very first time after replacing the caliper? What color, were there particulates, etc
d) did you use a brand new unopened brake fluid container to add new brake fluid?
Recommendation:
a)flush the entire system with brand new unopened brake fluid.
b) replace the line from the master to the flex hose at the problem wheel.
c) bleed the entire system in the order specified for the vehicle.
To quote Rube, I am NOT a mechanic, The above represents my best attempt at analyzing your problem and recommending a solution. Use at your own risk. I do my best not to encourage people to spend money on things that will not fix the issue. And, as demonstrated to date, neither of us "shotgun" parts, as that does nothing but leave you with less money and a bunch of parts that do not necessarily have anything to do w solving the problem.
If there are holes in my analysis, I welcome all constructive criticism as it only helps everyone learn how the system DOES work and where my assumptions went wrong.
PLEASE, forum folks, read the above and see if I took a wrong turn somewhere. Brake lines are not cheap, and junkyard ones are likely to be corroded internally as well...
Last edited by derf; 08-12-2015 at 02:50 PM.