2008 Hybrid Brakes Failed Several Times
#12
11-12-2009, 04:34 PM
make that HAD the F22 now cancelled
our gubmint canceled the F-22...the ones we have are all we will have. the age of the fighter pilot is over. it will be done by RPV's we have 2 operational predator wings flying in afganistan now...and they are being flown from nevada! the pilots role will be reduced to COIN operations and cargo hauling.
its a brave new world out there!
its a brave new world out there!
#13
11-12-2009, 07:15 PM
Re: 2008 Hybrid Brakes Failed Several Times
I think Jet1 clarified how you should hold a technical discussion, in-general.
Specifically, yes I looked under the hood even before I bought it, as I helped the dealer learn how to jump start the demo unit.
Secondly, I do all of my own brake work, and I have been through the technical data on this vehicle as a subscriber to All Data's service.
Third, the only vehicle I have ever heard of using "brake by wire" is the Mercedes S-class of several years ago, and that end very poorly for Merz. For the foreseeable future, all vehicles will be shipping with a hydraulic system for braking, even if a large portion is normally done with electric motors, as on the Tahoe Hybrid.
Lastly, in my opinion the original poster was, at best, disingenuous, if not just a fraud.
Specifically, yes I looked under the hood even before I bought it, as I helped the dealer learn how to jump start the demo unit.
Secondly, I do all of my own brake work, and I have been through the technical data on this vehicle as a subscriber to All Data's service.
Third, the only vehicle I have ever heard of using "brake by wire" is the Mercedes S-class of several years ago, and that end very poorly for Merz. For the foreseeable future, all vehicles will be shipping with a hydraulic system for braking, even if a large portion is normally done with electric motors, as on the Tahoe Hybrid.
Lastly, in my opinion the original poster was, at best, disingenuous, if not just a fraud.
#16
11-14-2009, 06:46 AM
Re: 2008 Hybrid Brakes Failed Several Times
The idea I was trying to get across in my original post (badly, as it turned out) was this: Yes, the brakes are conventional hydraulic. But the electric vs. vacuum assist part is a huge difference. Because of the regen braking capability, there is a dedicated brake ECU that needs to be properly programmed, and matched in their release level with the other hybrid ECUs. Then on top of that the electric assist system has its own multi-step learn procedure that must be completed exactly. Basically it learns the zero point and range of the travel of the electric assist, the zero point of the brake pedal (which can't be touched during the learn process) and purges the system. If you sit and listen after a typical key-off you'll hear it going through a purge cycle for about a minute.
The system works very well when it's setup correctly, but if any step gets missed, there will be messages like SERVICE STABILITRAK, SERVICE BRAKES SOON, etc and warning lights on the panel.
In another thread about the transmission recall one poster said their truck was kept an extra day for EBCM programming issues. This is probably why. The dealer was probably making sure that the programming and learn process was properly completed. There are some other issues with the dealer service programming tool that have to be paid attention to, like making sure they download the updated files correctly, and that the 12V system stays sufficiently charged during programming.
There's a lot more to pay attention to with this system than standard brakes. But electric assist will prevent what's happening to the Lexus' when they accelerate to wide-open throttle and lose all their brake assist because there's no manifold vacuum to assist. Electric assist doesn't care about manifold vacuum.
The two-mode hybrid system is a tremendous technical accomplishment, but is very complex, and many dealers don't even want to deal with them. Only a fraction of Chevy dealers even sell and service them. And I've run into too many dealers of all kinds that throw out lame excuses to customers rather than admit they don't really know what they're doing.
The system works very well when it's setup correctly, but if any step gets missed, there will be messages like SERVICE STABILITRAK, SERVICE BRAKES SOON, etc and warning lights on the panel.
In another thread about the transmission recall one poster said their truck was kept an extra day for EBCM programming issues. This is probably why. The dealer was probably making sure that the programming and learn process was properly completed. There are some other issues with the dealer service programming tool that have to be paid attention to, like making sure they download the updated files correctly, and that the 12V system stays sufficiently charged during programming.
There's a lot more to pay attention to with this system than standard brakes. But electric assist will prevent what's happening to the Lexus' when they accelerate to wide-open throttle and lose all their brake assist because there's no manifold vacuum to assist. Electric assist doesn't care about manifold vacuum.
The two-mode hybrid system is a tremendous technical accomplishment, but is very complex, and many dealers don't even want to deal with them. Only a fraction of Chevy dealers even sell and service them. And I've run into too many dealers of all kinds that throw out lame excuses to customers rather than admit they don't really know what they're doing.
#17
11-14-2009, 07:53 AM
here is some further reading for you
http://www.bodyshopbusiness.com/Arti...ecautions.aspx
be aware that the hybrid has 3 systems, hydraulic, regenerative and E brake. all interact but all are their own system. the odds of an E brake failure are so small as to be insignificant.
Hyd failure could happen but again the odds are VERY VERY SMALL as two separate hyd systems would have to fail.
Regenerative braking is new and could cause issues but complete brake failure NO WAY...
I think someone is trying to get out of a ticket and get the mfg. to buy back his car as he bought something he DID NOT UNDERSTAND and COULD NOT AFFORD.
I have found that people like this have NEVER owned a good car and are never satisfied. I'll bet that his last car was "a piece of crap" and the car before that was "a piece of crap" and THE NEXT CAR will also be "a piece of crap"
be aware that the hybrid has 3 systems, hydraulic, regenerative and E brake. all interact but all are their own system. the odds of an E brake failure are so small as to be insignificant.
Hyd failure could happen but again the odds are VERY VERY SMALL as two separate hyd systems would have to fail.
Regenerative braking is new and could cause issues but complete brake failure NO WAY...
I think someone is trying to get out of a ticket and get the mfg. to buy back his car as he bought something he DID NOT UNDERSTAND and COULD NOT AFFORD.
I have found that people like this have NEVER owned a good car and are never satisfied. I'll bet that his last car was "a piece of crap" and the car before that was "a piece of crap" and THE NEXT CAR will also be "a piece of crap"
Last edited by jet1; 11-14-2009 at 08:11 AM.
#18
11-14-2009, 12:29 PM
Re: 2008 Hybrid Brakes Failed Several Times
Great discussion guys. Just wanted to add my 2 pennies and note that KC125R has continued the discussion in a "professional" way 
It's refreshing to see this type of back and forth and have someone with the ***** to admit being wrong then positively contribute to the thread. This is a big reason why I keep coming back to this board.....
Aloha everyone....
By the way, I'm in agreement that the original poster must have credibility "issues", no response since day one .......
It's refreshing to see this type of back and forth and have someone with the ***** to admit being wrong then positively contribute to the thread. This is a big reason why I keep coming back to this board.....Aloha everyone....
By the way, I'm in agreement that the original poster must have credibility "issues", no response since day one .......
#19
11-14-2009, 01:32 PM
bah what would someone from Hawaii know...
Great discussion guys. Just wanted to add my 2 pennies and note that KC125R has continued the discussion in a "professional" way It's refreshing to see this type of back and forth and have someone with the ***** to admit being wrong then positively contribute to the thread. This is a big reason why I keep coming back to this board.....
Aloha everyone....
By the way, I'm in agreement that the original poster must have credibility "issues", no response since day one .......
It's refreshing to see this type of back and forth and have someone with the ***** to admit being wrong then positively contribute to the thread. This is a big reason why I keep coming back to this board.....Aloha everyone....
By the way, I'm in agreement that the original poster must have credibility "issues", no response since day one .......
I sure hope you appreciate your circumstances!
