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100% brake system failure ( Can this happen to your SC 430?)
Guys
I remember a few months ago we had a Fellow SC 430
owner experiencing 100% ABS failure while driving
on the freeway.
As a diehard SC fan, it is concerning to see this in an SC
There is another recent SC owner with 122K miles on
his SC where the lights in the dashboard were flashing
and going off.
I know now our SC is not vacuum controlled and the brake MC
booster with the ABS is a one electronic unit.
As the SC ages and more miles or older SC is on the road
I think this potential dangerous issue with SC can be more
common. I cannot imagined if an SC owners is driving down
a hill on the freeway and this sudden lost of brakes happen.
Should SC owners start thinking about replacing the
hydraulic ABS canaster before it loses pressure due to
age? Maybe do a group buy as a club?
The ABS canister losing pressure due to mileage or
time/age is very disturbing.
I remember a few months ago we had a Fellow SC 430
owner experiencing 100% ABS failure while driving
on the freeway.
As a diehard SC fan, it is concerning to see this in an SC
There is another recent SC owner with 122K miles on
his SC where the lights in the dashboard were flashing
and going off.
I know now our SC is not vacuum controlled and the brake MC
booster with the ABS is a one electronic unit.
As the SC ages and more miles or older SC is on the road
I think this potential dangerous issue with SC can be more
common. I cannot imagined if an SC owners is driving down
a hill on the freeway and this sudden lost of brakes happen.
Should SC owners start thinking about replacing the
hydraulic ABS canaster before it loses pressure due to
age? Maybe do a group buy as a club?
The ABS canister losing pressure due to mileage or
time/age is very disturbing.
Here is the thread to the most recent guy who has a problem and in his thread, I linked the thread you were talking about...see post #9.
i just want to keep the subject connected in all three threads because you referenced a thread with no link...and it just gets more confusing down the road...
Let’s be straight on this subject...the brake master cylinder will still engage the brake pads as long as you still have brake fluid in the system.
If you are leaking brake fluid, they may not operate.
if you loose electrical power, the engine, a pump or accumulator, the brakes WILL still operate...the pedal my be hard to push, but push that pedal to the floor or try...the car will stop.
100% brake failure can happen to any car...
MJT331, the person who said his brakes failed 100% also said, he had an internal leak...
I just tested my SC430 brakes with the engine and electrical off...and they still function...they will stop the car.
our brake system will operate on its hydraulic ability, all alone.
The brake system has a reserve. That is what the "brake booster accumulator" does. So if your engine or electrical system dies you will have enough left to stop the car. Once that is gone, the car is almost impossible to stop. To Bgw70, try another test. Go somewhere where there is a long slow decline. put the car in neutral, engine off and go down the hill. At first you will have braking power. after sever pumps. the reserve will be gone and the car will be VERY difficult to stop. (actually Bgw70 don't try it, I want you and your SC safe) To be totally truthful, I have not done this with the SC but have done it with a BMW (E46 M3, long story, I wasn't trying to do this, but it happened) I have had the brake booster failure in my SC . Fortunately the failure occurred in a parking lot, not a freeway. My son, who can do 900 lbs on the leg press, had trouble stopping it.
Just to be safe. If you are reading this and actually going to try the brake test, please don't, it can get dangerous fast. That said I can't stop you. DO NOT TRY IT ON A STEEP HILL. Be sure you have a wide clear area, no one else is around, your steering column is not locked. leave the keys in the ignition so you can start it quickly. Don't count on you Ebrake.
Sorry to ask but I am not sure Who in their right mind would honestly do the test
you are suggesting which is going down a hill
to see if the brakes work or to simulate the booster
failure?
The brake system has a reserve. That is what the "brake booster accumulator" does. So if your engine or electrical system dies you will have enough left to stop the car. Once that is gone, the car is almost impossible to stop. To Bgw70, try another test. Go somewhere where there is a long slow decline. put the car in neutral, engine off and go down the hill. At first you will have braking power. after sever pumps. the reserve will be gone and the car will be VERY difficult to stop. (actually Bgw70 don't try it, I want you and your SC safe) To be totally truthful, I have not done this with the SC but have done it with a BMW (E46 M3, long story, I wasn't trying to do this, but it happened) I have had the brake booster failure in my SC . Fortunately the failure occurred in a parking lot, not a freeway. My son, who can do 900 lbs on the leg press, had trouble stopping it.
Just to be safe. If you are reading this and actually going to try the brake test, please don't, it can get dangerous fast. That said I can't stop you. DO NOT TRY IT ON A STEEP HILL. Be sure you have a wide clear area, no one else is around, your steering column is not locked. leave the keys in the ignition so you can start it quickly. Don't count on you Ebrake.
finding any hill in Florida is difficult.
in my previous post, I said I did what you suggested, I was just not very detailed...here are the details.
i backed the car out of the garage, it was now sitting in my driveway which has a slight slope.
i turned the key off and I left the shifter in neutral
i let the car roll a little and still had plenty of brake power.
i knew the accumulator was supplying boost.
set the e-brake
pumped the brakes about 15-20 times
released the e-braked and still had brakes but I am pretty sure I only had front brakes...
now your thinking, why only front brakes, right?
because, if anyone has ever bled the brakes in our cars, they know the front brakes are bled the traditional way by pumping the pedal several times, they hold the pedal down and have a partner open the bleeder screw on the caliper. The brake fluid will come out. Close the blended screw, pump the brakes and pressure returns...repeat.
the rear brakes are different, they are applied by the car. You must have the car turned on and the pump will send brake fluid to the rear brakes. So to bleed the rear brakes, you must have the car electrical turned on...key on, engine off...press the brake pedal down, release the bleeder screw and the pump will continue to push fluid to the rear brakes...it makes it easy to bleed the rear brakes...
in summary, if your brake system is operating normally, you will have brakes when the engine and electrical off. The rear brakes will stop working after you pump the brakes 10-20 times.
the front brakes will continue to function...
this is how my 2002 and 2007 SC430s operate.
if you have brake problems, your results may be different.
when i first purchased my 2002, the brake master cylinder started leaking...I replaced it with another master cylinder from a 2005 salvage car...it’s been four years and no issues...
Sorry to ask but I am not sure Who in their right mind would honestly do the test
you are suggesting which is going down a hill
to see if the brakes work or to simulate the booster
failure?
dont forget, if you have total brake failure, use the ebrake...
downshift to slow the car while slowly applying the ebrake until the car stops...
This procedure proves what I said is correct...
engine and electrical off...you will still have front brakes and front brakes do 75% of the stopping...rears only do 25%
and don’t forget you still have the E-brake on the rear wheels.
Folks, brakes can fail in any car...I have no fear driving an SC430...i also have no fear of my wife driving her SC430.
maintain your car...is the brake fluid black or yellow/clear?
if black, you are NOT maintaining your car.
So I am clear, are you saying “in short”
as long as your system does not show brake fluid
leaking , you will have “ brakes “ to stop the car
if there is complete sudden brake failure to the ABS
system ? And follow the below steps
1- Down shift
2- step in the emergency brake “ slowly “
while you down shift and donot slam the emergency
brake all the way to the floor?
3- step on the brakes the same time you follow
#2 snd #3 ?
Did I summarize correctly ?
Both of the above procedure should be done
simultaneously?
Final question which is the $$$$ question , how many drivers at a sudden
panic will know they need to do #2 and #3 though ?
So I am clear, are you saying “in short”
as long as your system does not show brake fluid
leaking , you will have “ brakes “ to stop the car
if there is complete sudden brake failure to the ABS
system ? And follow the below steps
1- Down shift
2- step in the emergency brake “ slowly “
while you down shift and donot slam the emergency
brake all the way to the floor?
3- step on the brakes the same time you follow
#2 snd #3 ?
Did I summarize correctly ?
Both of the above procedure should be done
simultaneously?
Final question which is the $$$$ question , how many drivers at a sudden
panic will know they need to do #2 and #3 though ?
Now the question
yep, you are correct...just do those steps.
my Dad taught me those steps when I was 14...
we even practiced...go practice on an empty road...
Go 40mph and stop yourself by downshifting and the ebrake....focus more on the downshifting and gradually apply the ebrake.
I have never try this as I didn’t want to Damage
the AT but I guess it should be ok
Now I won’t have to worry about having to sell
my SC to go run buy an * LC 500
* That is the next Lexus I am buying
i hope they have an LC500C (Convertible) when your ready!
i can assure you, this will not damage the transmission...
I was just out with my wife and I asked her what she would do if the brakes went to the floor...she paused and said I would try to pump them...Good answer...then I said, it didn’t help, now what?
she responded with I don’t know...
i showed her what to do, down shifting the car then applying the e-brake...
11-16-18, 06:22 AM
100% brake system failure ( Can this happen to your SC 430?)
