03' GX470 disables brake & all lights on - Mechanic shops no help
#1
10th Gear
Thread Starter
03' GX470 disables brake & all lights on - Mechanic shops no help
Hello fellow GX drivers,
I want to share an experience that is still a mystery to me with my 03' GX470 with 144k miles.
A couple of weeks ago while out of town waiting in the drive-thru of a restaurant, all of sudden my ABS, Brake, VSC, etc light comes on and the brake paddle becomes hard as pushing a 2x4 where brake becomes disabled and doesn't work. So by using the emergency hand brake to get through the line, and meanwhile, the brake goes from hard as a board to soften state like a regular brake which grips. This process continues intermittently. I took some risks to drive a couple of miles to a large parking lot of a school where I called Uber to get home. I had brake fluid leaks, master cylinder failure, and a few brake problems over the year of different vehicles, but never like the situation I described above.
Here is the mystery: The following Monday, I had GX470 towed to my tire/mechanic shop I've been going since 1995. The head mechanic calls me and recommends to take it to the Lexus dealer. He said it seems like a brake hydraulic related issue and didn't want to mess with it. I had it towed to a different mechanic who fixed my 07 GX450h's ABS brake assembly last year. He calls and recommends taking it to the dealership, stating he had tried to a similar issue in the past but without a success. And since the Toyota dealership was much closer, I had it towed to the dealership. The next day the serviceman calls and tells me that the GX needed to replace the complete brake assembly including the master cylinder and cost OTD is $4100. Weighing risk/benefit analysis and a bit of desperation, I take it to a different mechanic my sister had used. (The mechanic from her neighborhood who used his home garage to start building his business and hungry to grow and now has a bigger shop). He calls me the next day. The GX wouldn't start so he replaced the battery and since then he put 5-mile driving without any brake problems. I asked him to drive more miles and told him to be careful. After his shop mechanics driving it over five more days and an additional 25 miles without any brake issues, the mechanic thinks it was a voltage issue, although he wasn't completely certain. He said he has seen a low voltage cause all kinds of weird mechanical issues.
So, I am happy to be driving my GX and paid less than 10% of what the Toyota dealership quoted. I have now given a nicknamed my GX: Butter (since it's so smooth).
Has anyone had a similar breakdown due to the brake issue I described? If so, what was the solution for you?
Thank you in advance and I hope by sharing my experience, it can help someone else.
I want to share an experience that is still a mystery to me with my 03' GX470 with 144k miles.
A couple of weeks ago while out of town waiting in the drive-thru of a restaurant, all of sudden my ABS, Brake, VSC, etc light comes on and the brake paddle becomes hard as pushing a 2x4 where brake becomes disabled and doesn't work. So by using the emergency hand brake to get through the line, and meanwhile, the brake goes from hard as a board to soften state like a regular brake which grips. This process continues intermittently. I took some risks to drive a couple of miles to a large parking lot of a school where I called Uber to get home. I had brake fluid leaks, master cylinder failure, and a few brake problems over the year of different vehicles, but never like the situation I described above.
Here is the mystery: The following Monday, I had GX470 towed to my tire/mechanic shop I've been going since 1995. The head mechanic calls me and recommends to take it to the Lexus dealer. He said it seems like a brake hydraulic related issue and didn't want to mess with it. I had it towed to a different mechanic who fixed my 07 GX450h's ABS brake assembly last year. He calls and recommends taking it to the dealership, stating he had tried to a similar issue in the past but without a success. And since the Toyota dealership was much closer, I had it towed to the dealership. The next day the serviceman calls and tells me that the GX needed to replace the complete brake assembly including the master cylinder and cost OTD is $4100. Weighing risk/benefit analysis and a bit of desperation, I take it to a different mechanic my sister had used. (The mechanic from her neighborhood who used his home garage to start building his business and hungry to grow and now has a bigger shop). He calls me the next day. The GX wouldn't start so he replaced the battery and since then he put 5-mile driving without any brake problems. I asked him to drive more miles and told him to be careful. After his shop mechanics driving it over five more days and an additional 25 miles without any brake issues, the mechanic thinks it was a voltage issue, although he wasn't completely certain. He said he has seen a low voltage cause all kinds of weird mechanical issues.
So, I am happy to be driving my GX and paid less than 10% of what the Toyota dealership quoted. I have now given a nicknamed my GX: Butter (since it's so smooth).
Has anyone had a similar breakdown due to the brake issue I described? If so, what was the solution for you?
Thank you in advance and I hope by sharing my experience, it can help someone else.
Last edited by Flagolfer; 03-05-20 at 04:42 AM. Reason: clarity
#2
Pole Position
It was possible it was low voltage.
The GX doesn't use the typical vacuum assist brake system, it uses an electric-motor driven brake assist system (brake booster). And they have been known to fail once they get old. Parts cost is about $3300, so $4100 with labor is high, but not crazy high.
https://www.mylparts.com/oem-parts/l...QtN2wtdjgtZ2Fz
I would keep a careful eye on it, and at the first hint of a problem (I like being able to stop...) I would get it towed to the mechanic and either put a new master cylinder in, or scrap the vehicle, depending on the economics and your desire to keep it.
Chip H.
The GX doesn't use the typical vacuum assist brake system, it uses an electric-motor driven brake assist system (brake booster). And they have been known to fail once they get old. Parts cost is about $3300, so $4100 with labor is high, but not crazy high.
https://www.mylparts.com/oem-parts/l...QtN2wtdjgtZ2Fz
I would keep a careful eye on it, and at the first hint of a problem (I like being able to stop...) I would get it towed to the mechanic and either put a new master cylinder in, or scrap the vehicle, depending on the economics and your desire to keep it.
Chip H.
The following users liked this post:
Flagolfer (02-21-20)
#3
10th Gear
Thread Starter
It was possible it was low voltage.
The GX doesn't use the typical vacuum assist brake system, it uses an electric-motor driven brake assist system (brake booster). And they have been known to fail once they get old. Parts cost is about $3300, so $4100 with labor is high, but not crazy high.
https://www.mylparts.com/oem-parts/l...QtN2wtdjgtZ2Fz
I would keep a careful eye on it, and at the first hint of a problem (I like being able to stop...) I would get it towed to the mechanic and either put a new master cylinder in, or scrap the vehicle, depending on the economics and your desire to keep it.
Chip H.
The GX doesn't use the typical vacuum assist brake system, it uses an electric-motor driven brake assist system (brake booster). And they have been known to fail once they get old. Parts cost is about $3300, so $4100 with labor is high, but not crazy high.
https://www.mylparts.com/oem-parts/l...QtN2wtdjgtZ2Fz
I would keep a careful eye on it, and at the first hint of a problem (I like being able to stop...) I would get it towed to the mechanic and either put a new master cylinder in, or scrap the vehicle, depending on the economics and your desire to keep it.
Chip H.
Any suggestion to look for things to prevent? I have been reading GX forum a bit but since I am not DIY, I am concerned.
Thanks again.
#4
Lexus Fanatic
Hello fellow GX drivers,
I want to share an experience that is still a mystery to me with my 03' GX470 with 144k miles.
A couple of weeks ago while out of town waiting in the drive-thru of a restaurant, all of sudden my ABS, Brake, VSC, etc light comes on and the brake paddle becomes hard as pushing a 2x4 where brake becomes disabled and doesn't work. So by using the emergency hand brake to get through the line, and meanwhile, the brake goes from hard as a board to soften state like a regular brake which grips. This process continues intermittently. I took some risks to drive a couple of miles to a large parking lot of a school where I called Uber to get home. I had brake fluid leaks, master cylinder failure, and a few brake problems over the year of different vehicles, but never like the situation I described above.
Here is the mystery: The following Monday, I had GX470 towed to my tire/mechanic shop I've been going since 1995. The head mechanic calls me and recommends to take it to the Lexus dealer. He said it seems like a brake hydraulic related issue and didn't want to mess with it. I had it towed to a different mechanic who fixed my 07 GX450h's ABS brake assembly last year. He calls and recommends taking it to the dealership, stating he had tried to a similar issue in the past but without a success. And since the Toyota dealership was much closer, I had it towed to the dealership. The next day the serviceman calls and tells me that the GX needed to replace the complete brake assembly including the master cylinder and cost OTD is $4100. Weighing risk/benefit analysis and a bit of desperation, I take it to a different mechanic my sister had used. (The mechanic from her neighborhood who used his home garage to start building his business and hungry to grow and now has a bigger shop). He calls me the next day. The GX wouldn't start so he replaced the battery and since then he put 5-mile driving without any brake problems. I asked him to drive more miles and told him to be careful. After his shop mechanics driving it over five more days and an additional 25 miles without any brake issues, the mechanic thinks it was a voltage issue, although he wasn't completely certain. He said he has seen a low voltage cause all kinds of weird mechanical issues.
So, I am happy to be driving my GX and paid less than 10% of what the Toyota dealership quoted. I have now given a nicknamed my GX: Butter (since it's so smooth).
Has anyone had a similar breakdown due to the brake issue I described? If so, what was the solution for you?
Thank you in advance and I hope by sharing my experience, it can help someone else.
I want to share an experience that is still a mystery to me with my 03' GX470 with 144k miles.
A couple of weeks ago while out of town waiting in the drive-thru of a restaurant, all of sudden my ABS, Brake, VSC, etc light comes on and the brake paddle becomes hard as pushing a 2x4 where brake becomes disabled and doesn't work. So by using the emergency hand brake to get through the line, and meanwhile, the brake goes from hard as a board to soften state like a regular brake which grips. This process continues intermittently. I took some risks to drive a couple of miles to a large parking lot of a school where I called Uber to get home. I had brake fluid leaks, master cylinder failure, and a few brake problems over the year of different vehicles, but never like the situation I described above.
Here is the mystery: The following Monday, I had GX470 towed to my tire/mechanic shop I've been going since 1995. The head mechanic calls me and recommends to take it to the Lexus dealer. He said it seems like a brake hydraulic related issue and didn't want to mess with it. I had it towed to a different mechanic who fixed my 07 GX450h's ABS brake assembly last year. He calls and recommends taking it to the dealership, stating he had tried to a similar issue in the past but without a success. And since the Toyota dealership was much closer, I had it towed to the dealership. The next day the serviceman calls and tells me that the GX needed to replace the complete brake assembly including the master cylinder and cost OTD is $4100. Weighing risk/benefit analysis and a bit of desperation, I take it to a different mechanic my sister had used. (The mechanic from her neighborhood who used his home garage to start building his business and hungry to grow and now has a bigger shop). He calls me the next day. The GX wouldn't start so he replaced the battery and since then he put 5-mile driving without any brake problems. I asked him to drive more miles and told him to be careful. After his shop mechanics driving it over five more days and an additional 25 miles without any brake issues, the mechanic thinks it was a voltage issue, although he wasn't completely certain. He said he has seen a low voltage cause all kinds of weird mechanical issues.
So, I am happy to be driving my GX and paid less than 10% of what the Toyota dealership quoted. I have now given a nicknamed my GX: Butter (since it's so smooth).
Has anyone had a similar breakdown due to the brake issue I described? If so, what was the solution for you?
Thank you in advance and I hope by sharing my experience, it can help someone else.
The following users liked this post:
Flagolfer (03-04-20)
#5
10th Gear
Thread Starter
Ha, thanks for the heads up. I just texted my mechanic "what if" since there is a slow churning noise (sounds like the electrical motor in directly front of the driver seat, and a whiny noise at the start of the morning till warms up). Plus, I added your comment "could be pending alternator." I'll know in a few days and if anything new, I will report.
#6
10th Gear
Thread Starter
I was at the mechanic shop picking up my daughter's Civic. I asked him about him checking the alternator of the GX, and he said it was good. So... the mystery is still there while I drive my Butter.
#7
Driver School Candidate
I just had this happen yesterday. The sporadic whining sound right in front of the driver's seat followed by the brake alarm and dash brake lights about 3 miles later. I didn't lose brake assist but did immediately take it to my garage. Half way to the garage all of the lights went off but I went ahead and took it anyway. They diagnosed it as an internal leak in the Master ABS motor system which causes it to overheat. They explained what was said above about the GX having a motor assisted braking system which is dangerous if it stops working.
They are getting the entire Master Cylinder/ABS assembly from Lexus for $1879 and $400 for the install so not as bad as what you experienced.
They are getting the entire Master Cylinder/ABS assembly from Lexus for $1879 and $400 for the install so not as bad as what you experienced.
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