Brake Drama
05-13-19, 06:32 PM
#31
And here's the funny thing. When it would happen I would literally bang it with a hammer and it would stop. I'm actually embarrassed to admit that here, but hey, it worked!
05-15-19, 07:39 AM
#32
Originally Posted by PackmanJim
My brake actuator went out a couple of weeks ago at 90K miles. I'm new at posting here so please don't slam me. lol
Are you under the extended warranty?
And FWIW, most people here are very helpful. Recent exceptions (as seen here, earlier on, and on a different thread) are arguably rare.
So, you shouldn't get slammed by anyone. This guy below (hammer and all), that's a different story.
Originally Posted by Nospinzone
When it would happen I would literally bang it with a hammer and it would stop. I'm actually embarrassed to admit that here, but hey, it worked!
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PackmanJim (05-29-19)
05-16-19, 01:07 AM
#33
Driver School Candidate
Looks like have the exact same issue. My car has the frequent priming and now my dash is lit up the same way. Time to open the wallet again. I just replaced the front suspension components at over 2k.
05-16-19, 05:23 AM
#34
Ok, here’s another quick question while I’m checking this stuff out. I’m not sure if this is normal or not, but my car has always done this sort of priming as long as I have had it. I have removed some of the engine plastic prices and the brake actuator is definitely the culprit of the noise.
Is this normal?????
https://youtu.be/tv_U82Gjp-s
Is this normal?????
https://youtu.be/tv_U82Gjp-s
05-16-19, 09:10 AM
#35
@Gjohnson Hello sir, any update to your situation?
About two weeks ago my 07 LS460L 103k miles has started making a quick squawk/chirp noise, on occasion, when I tap the brake pedal. I really hope it's not the actuator going out. Per Lexus driver's site, the actuator was replaced when the car had only 8k miles in 2008. The squawk fits happen randomly and seem to disappear as quick as they appear.
@Julez
I've noticed when the squawks happen the brake pedal pulses when coming to a stop, as if the rotors are warped. I'm certain it's related to the actuator because the pulsation only happens during the squawk fits.
Do you guys feel a brake fluid change/flush might help? I have Techstream and no ABS codes are showing up.
About two weeks ago my 07 LS460L 103k miles has started making a quick squawk/chirp noise, on occasion, when I tap the brake pedal. I really hope it's not the actuator going out. Per Lexus driver's site, the actuator was replaced when the car had only 8k miles in 2008. The squawk fits happen randomly and seem to disappear as quick as they appear.
@Julez
I've noticed when the squawks happen the brake pedal pulses when coming to a stop, as if the rotors are warped. I'm certain it's related to the actuator because the pulsation only happens during the squawk fits.
Do you guys feel a brake fluid change/flush might help? I have Techstream and no ABS codes are showing up.
05-17-19, 01:06 PM
#36
@Gjohnson Hello sir, any update to your situation?
About two weeks ago my 07 LS460L 103k miles has started making a quick squawk/chirp noise, on occasion, when I tap the brake pedal. I really hope it's not the actuator going out. Per Lexus driver's site, the actuator was replaced when the car had only 8k miles in 2008. The squawk fits happen randomly and seem to disappear as quick as they appear.
@Julez
I've noticed when the squawks happen the brake pedal pulses when coming to a stop, as if the rotors are warped. I'm certain it's related to the actuator because the pulsation only happens during the squawk fits.
Do you guys feel a brake fluid change/flush might help? I have Techstream and no ABS codes are showing up.
About two weeks ago my 07 LS460L 103k miles has started making a quick squawk/chirp noise, on occasion, when I tap the brake pedal. I really hope it's not the actuator going out. Per Lexus driver's site, the actuator was replaced when the car had only 8k miles in 2008. The squawk fits happen randomly and seem to disappear as quick as they appear.
@Julez
I've noticed when the squawks happen the brake pedal pulses when coming to a stop, as if the rotors are warped. I'm certain it's related to the actuator because the pulsation only happens during the squawk fits.
Do you guys feel a brake fluid change/flush might help? I have Techstream and no ABS codes are showing up.
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terminater (05-29-19)
05-17-19, 03:35 PM
#37
Driver
Thread Starter
Update: I have been driving the car for a few days without any issues, then Wednesday afternoon the codes came back. At this point I parked the car and picked up a rental. My TechStream setup just came in the mail today, so I have started learning how to use the software. I plan to try the brake bleeding process, but took a quick video of the ABS readings of the car isolines in the garage. I saw another thread posting about the desired Accumulator voltage and if I am remembering correctly you want the numbers between 3.2-4.0 volts. I noticed my readings are typically above that mark, but dip every now and then to around 3.17V. Does anyone know if that should be a concern?
Edit: I just reread the post I got this info from and the test should be done with the car off and ignition on. I will need to gather the data again.
Edit: I just reread the post I got this info from and the test should be done with the car off and ignition on. I will need to gather the data again.
Last edited by Gjohnson; 05-17-19 at 03:46 PM.
05-17-19, 08:31 PM
#38
Driver
Thread Starter
Well, its been a long night, but I'm feeling hopeful. After a few hours of bleeding the brakes via TechStream my Accumulator reading are holding steady in the 3.2 - 4.0V range. I basically bled the breaks 3 full times to make sure I got all the air out of the lines and really cleared out all the old fluid. I actually had to take a break between bleeding to make a Auto parts run a pick up more brake fluid. After this treatment, I no longer get the Actuator priming that I posted about earlier. The only time I hear the Actuator run is after the brake pedal has been depressed, which I only assume is to make sure the pressure stays within range. From what I can analyze from this situation, my brake system was full of trapped air, through out the all the lines. I'm not sure if I'm out of the woods yet, but the brake pedal feels a lot better and it seems like the Actuator doesn't have to work nearly as much.
The new Accumulator readings below don't move, unless the break is depressed. As you can see from the previous video, the prior readings would continuously fluctuate and the Actuator would keep kicking on to adjust the pressure.
The new Accumulator readings below don't move, unless the break is depressed. As you can see from the previous video, the prior readings would continuously fluctuate and the Actuator would keep kicking on to adjust the pressure.
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jdanielca (05-18-19)
05-23-19, 10:31 AM
#39
Driver
Thread Starter
Ok, well apparently I’m not out of the woods yet. It’s almost been a week since I finished my brake bleed and now my Brake Accumulator values are going crazy again. So does anyone know if this seals the deal on the Actuator or could it still be a bad brake skip control ecu? I’ve inspected the brake lines and can’t see any leaking, so I’ve ruled that out.
Posting this information from the previous thread for reference. Great information from yyymmm31.
After rereading this again. I am pretty positive my issue is the Actuator.
Posting this information from the previous thread for reference. Great information from yyymmm31.
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Before I answer your question, I have a small request for you. Please keep us posted and share with us how you eventually solve the problem. I answered quite a few 1-posting questions. After I took the time to provide my recommendations, the person who posted the question never came back to share if the problem was solved and how it was resolved. Sharing information on this forum will help others who may have the same problem in the future.
-Yes, you can do a lot at home, if you are willing to do it, including fully fixing the problem on your own. Error code C1391 (and C1396) suggests three possible problems: (1) leak in brake hoses between the brake actuator and brake caliper (i.e., not an actuator problem), (2) a bad brake skip control ECU (i.e., again, not an actuator problem), and (3) a bad brake actuator.
-The first step is to check if there is any external leaks on brake hoses. If there is any leak on a brake hose, replace the broken hose and problem is solved.
-If there is no leaks on brake hoses, if you are handy and have Techstream, you can check the brake actuator pressure voltage. A functional brake actuator should have a voltage range of 3.2-4.0V. You do this test with the engine ignition at ON position (but not actually starting the engine). If the brake actuator pressure is not in the normal range, you can do a full brake bleeding with Techstream per factory service procedure and see if the full brake bleeding fix the problem. In some cases, full brake bleeding fixes the problem. If a full bleeding doesn't fix the problem, you will need to replace the brake actuator.
-If your brake actuator has the normal voltage range of 3.2-4.0V, then, your brake skip control ECU is bad and you need to replace it, not the brake actuator.
Hope that this is helpful. Again, please keep us posted about the outcomes.
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Before I answer your question, I have a small request for you. Please keep us posted and share with us how you eventually solve the problem. I answered quite a few 1-posting questions. After I took the time to provide my recommendations, the person who posted the question never came back to share if the problem was solved and how it was resolved. Sharing information on this forum will help others who may have the same problem in the future.
-Yes, you can do a lot at home, if you are willing to do it, including fully fixing the problem on your own. Error code C1391 (and C1396) suggests three possible problems: (1) leak in brake hoses between the brake actuator and brake caliper (i.e., not an actuator problem), (2) a bad brake skip control ECU (i.e., again, not an actuator problem), and (3) a bad brake actuator.
-The first step is to check if there is any external leaks on brake hoses. If there is any leak on a brake hose, replace the broken hose and problem is solved.
-If there is no leaks on brake hoses, if you are handy and have Techstream, you can check the brake actuator pressure voltage. A functional brake actuator should have a voltage range of 3.2-4.0V. You do this test with the engine ignition at ON position (but not actually starting the engine). If the brake actuator pressure is not in the normal range, you can do a full brake bleeding with Techstream per factory service procedure and see if the full brake bleeding fix the problem. In some cases, full brake bleeding fixes the problem. If a full bleeding doesn't fix the problem, you will need to replace the brake actuator.
-If your brake actuator has the normal voltage range of 3.2-4.0V, then, your brake skip control ECU is bad and you need to replace it, not the brake actuator.
Hope that this is helpful. Again, please keep us posted about the outcomes.
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Last edited by Gjohnson; 05-23-19 at 10:35 AM.
05-23-19, 01:42 PM
#40
Intermediate
Ok, well apparently I’m not out of the woods yet. It’s almost been a week since I finished my brake bleed and now my Brake Accumulator values are going crazy again. So does anyone know if this seals the deal on the Actuator or could it still be a bad brake skip control ecu? I’ve inspected the brake lines and can’t see any leaking, so I’ve ruled that out.
https://youtu.be/S9RZ2OHpIqo
Posting this information from the previous thread for reference. Great information from yyymmm31.
After rereading this again. I am pretty positive my issue is the Actuator.
https://youtu.be/S9RZ2OHpIqo
Posting this information from the previous thread for reference. Great information from yyymmm31.
After rereading this again. I am pretty positive my issue is the Actuator.
Hi, Gjohnson. Before you head to replace the brake actuator, could you bleed the brake system one more time by following the procedure in Post 9 by Tlutrick (described in his attached PDF files) here: https://www.clublexus.com/forums/ls-...question.html? The brake bleed procedure posted by Tlutick is recommended by Lexus for repair shop technicians to verify if indeed the actuator is bad. If you still experience the problem after using Tlutrick's brake bleeding procedure, you may consider replacing brake actuator. Additionally, since brake actuator is an expensive part, you may also consider having a Lexus repair shop validate the diagnosis before purchasing a new brake actuator. Good luck. PS, your PM message went to one of my email accounts that I don't regularly check. Sorry for the delay of the reply. Good luck.
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Last edited by yyymmm31; 05-23-19 at 05:15 PM.
06-11-19, 07:10 PM
#41
Driver
Thread Starter
Hey guys, I know it’s been a couple of weeks but I swapped out the Brake Actuator and most issues seem to be fixed. I tried to take a couple pics of the process to possibly write up a DIY, however I’m not sure I have enough quality pics to complete one.
I’ve been driving the car for roughly 2 weeks and have not received a single check engine light or heard a sound from the actuator priming like I was accustomed to since owning the car. The priming issues I was having with the car have ceased, however I need to try a full brake bleed again. When I attempted the Actuator replacement bleed process my car battery got too low and the bleed process failed during the Actuator purge section. I got to 4/5 in this section and after it failed I could not get the process to run again. Every time I would attempt a full bleed, I would get a bleed failed message. Hopefully I will be able to find time this week to retry.
Right now I periodically get a low clang/bang sound from what I can only imagine is the rear brakes. I had never heard this sound before starting this process.
I’ve been driving the car for roughly 2 weeks and have not received a single check engine light or heard a sound from the actuator priming like I was accustomed to since owning the car. The priming issues I was having with the car have ceased, however I need to try a full brake bleed again. When I attempted the Actuator replacement bleed process my car battery got too low and the bleed process failed during the Actuator purge section. I got to 4/5 in this section and after it failed I could not get the process to run again. Every time I would attempt a full bleed, I would get a bleed failed message. Hopefully I will be able to find time this week to retry.
Right now I periodically get a low clang/bang sound from what I can only imagine is the rear brakes. I had never heard this sound before starting this process.
06-12-19, 11:38 AM
#44
Intermediate
Hey guys, I know it’s been a couple of weeks but I swapped out the Brake Actuator and most issues seem to be fixed. I tried to take a couple pics of the process to possibly write up a DIY, however I’m not sure I have enough quality pics to complete one.
I’ve been driving the car for roughly 2 weeks and have not received a single check engine light or heard a sound from the actuator priming like I was accustomed to since owning the car. The priming issues I was having with the car have ceased, however I need to try a full brake bleed again. When I attempted the Actuator replacement bleed process my car battery got too low and the bleed process failed during the Actuator purge section. I got to 4/5 in this section and after it failed I could not get the process to run again. Every time I would attempt a full bleed, I would get a bleed failed message. Hopefully I will be able to find time this week to retry.
Right now I periodically get a low clang/bang sound from what I can only imagine is the rear brakes. I had never heard this sound before starting this process.
I’ve been driving the car for roughly 2 weeks and have not received a single check engine light or heard a sound from the actuator priming like I was accustomed to since owning the car. The priming issues I was having with the car have ceased, however I need to try a full brake bleed again. When I attempted the Actuator replacement bleed process my car battery got too low and the bleed process failed during the Actuator purge section. I got to 4/5 in this section and after it failed I could not get the process to run again. Every time I would attempt a full bleed, I would get a bleed failed message. Hopefully I will be able to find time this week to retry.
Right now I periodically get a low clang/bang sound from what I can only imagine is the rear brakes. I had never heard this sound before starting this process.
With Techstream, run two procedures below:
1) Reset Memory, and
2) Linear Valve Offset Calibration
Then, re-run the brake bleeding procedure for replacing brake actuator, of course, with a fully charged battery.
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06-20-19, 07:32 PM
#45
Driver
Thread Starter
i ran the Reset Memory procedure and the linear valve offset calibration. I tried multiple times and the bleed process kept failing.
The upside is the brakes are still working great and no continuous actuator priming.