Gm Brembo upgrade added...sluggish acceleration and much lower mpg.

[randeez]

Hi guys! Just came back from dealership. Again, want to thank each and everyone of you for your input with this matter. Great info exchanged. So...trying to find a way to make this short. My visit to dealership was truly an experience. Will keep this as basic as possible and will answer questions whenever I log in. First service advisor drives car and definitely agrees something is wrong. Agreed with the symptoms I mentioned initially. We meet master tech and another adviser who requested to test drive the car. Both returned and said everything feels perfectly fine. I get extremely aggravated. Clearly the clowns have never driven a V8 to justify the way this driving. After arguing back and forth and not settling for my car to go back in the lift for them to just rotate rotor and say everything is OK, another "master tech" who seems to the most experience one at the dealership arrives. He is immediately notified to go on another test drive with me. We both remained quiet for whole test drove (awkward). Immediately after driving a few miles, we return to dealership and he requests that I exit the vehicle with him while he checks Temps. Both front rotors gave a reading within 4 degrees of eachother. Rear passenger rotors-breaks read 145 degrees. Rear drivers reads 210 degreese. Now, with these rear calipers-breaks...they actually contain the ebrake system right on it. It's either the installer jacked it up installing the things or the rear caliper or calipers are defective. He believes the ebrake somehow is somewhat active. The grooves on the rear driver side should have been a clear indication something was wrong but this damn dealership loves playing stupid games. He stated he can unplug the ebrake system and drive car but in uncertain what type of codes or nonsense he will have to reset after doing so. This part is on back order and will be hard to come around. Dealer will do a warranty claim - whatever that is with gm for a replacement. Tech is stating since steering is not swaying towards one direction, both sides may be dragging with one being worst. Will have to compare after new one is installed. The absolute weird thing is that non of us can feel the difference in heat by touch or scent. Only when we repeatedly put temp scanner to it we repeatedly get an avg of 60 degrees difference. No smell, fumes, irrgular hot wheels to the touch...just drastically difference Temboth sides. sides.

thanks for the update

possible the first time you brought it to them they thought upgrade included rear and tore one side down before realizing it? retracted the caliper and then put all the "used" parts back on?

sucks something that should be so simple dealership turned it into a mess

 

[Chad G 1979]

You know that both rears are dragging now and is causing the issue. With both dragging to some degree, they don't have to heat up a lot to cause a decent amout of drag. And when checking the temp by feel, were you touching the rotor or the calipers or wheel themselves? You should definitely be able to feel heat even at 145(thats hotter than straight hot water from a water heater is supposed to be). And at 210, you would burn yourself pretty quickly just touching it. They do need to fix the issue.

 

[George B]

I am surprised they didn't check to make sure it was all ok mechanically before they loaded up the parts canon.

 

[Tahoered]

I am surprised they didn't check to make sure it was all ok mechanically before they loaded up the parts canon.

I'm really leaning towards technician error tbh. These dealers are hiring anyone off the streets with limited experience.

 

[Tahoered]

You know that both rears are dragging now and is causing the issue. With both dragging to some degree, they don't have to heat up a lot to cause a decent amout of drag. And when checking the temp by feel, were you touching the rotor or the calipers or wheel themselves? You should definitely be able to feel heat even at 145(thats hotter than straight hot water from a water heater is supposed to be). And at 210, you would burn yourself pretty quickly just touching it. They do need to fix the issue.

I was doing it by carefully touching wheels and after a little even sticking fingers quickly for the touch. I guess that was the worst way to check since there was no way my fingers would be able to differentiate between very hot and extremely hot, lol. But hey, that's why I relied on all of you guys for some thoughts. I am grateful.

 

[WalleyeMikeIII]

I was doing it by carefully touching wheels and after a little even sticking fingers quickly for the touch. I guess that was the worst way to check since there was no way my fingers would be able to differentiate between very hot and extremely hot, lol. But hey, that's why I relied on all of you guys for some thoughts. I am grateful.

So, did they actually “fix” it??

 

[DuraYuk]

Sounds like they have no idea what the problem is. The temp differential is interesting. But a rotor should be getting hot if brakes are constantly dragging. That heat won't go away since it would be constant.

I wouldn't be surprised if their 'fix' doesn't fix it.

Just strange that the rears are messing up after a front brake upgrade.

Looking forward to the update after the 'fix'

 

[WalleyeMikeIII]

Sounds like they have no idea what the problem is. The temp differential is interesting. But a rotor should be getting hot if brakes are constantly dragging. That heat won't go away since it would be constant.

I wouldn't be surprised if their 'fix' doesn't fix it.

Just strange that the rears are messing up after a front brake upgrade.

Looking forward to the update after the 'fix'

There is a rear upgrade in this package...only cosmetic, but it is a new caliper, painted red to match the fronts.

 

[DuraYuk]

There is a rear upgrade in this package...only cosmetic, but it is a new caliper, painted red to match the fronts.

I see. Still in surprised the temps are not blazing hot. It's either dragging or its not. And since its not pulling it would have to be both sides but only showing higher temp on one. If it's not piping hot I think they are on a wild goose chase and the problem is elsewhere.

I've seen binding u joints cause this sort of thing. Labored driving etc.

Interested to see what it ends up being after the 'techs' are done throwing parts at it.

 

[Rocket Man]

I still don’t think it’s the brakes, they would really have to be dragging hard in order to cause that much of a drop in mpg and performance. And if it was the park brakes, the pads would wear down quickly and not be dragging much after awhile. I’m still leaning towards something electronic.