Very soft brakes intermittently?

20280 Views 22 Replies 12 Participants Last post by Mirage, Nov 18, 2021

Thorin78

Discussion Starter · Sep 29, 2014

I took delivery of our 2013 JX35 around Oct 2012. We have about 14000 miles on it. Lately, I've experienced what I would call as very soft brakes. It doesn't happen all the time and I'm not sure that I can repeat it consistently.

I would be driving down the road and coming to a stop, but the car won't stop until I step all the way down on the pedal. Normally, I can sense the car starting to stop at a very light touch and then stop fully when the pedal is half depressed. When I let go of the brakes during these instances, I can hear/feel a noise like something is sucking for air. It doesn't happen when it's stopping normally. Does anyone know what the brakes are doing when it's "sucking air"? When I let go of the brakes and reapply it, it immediately bites again as if nothing happened.

I've read a few other threads that are similar but all of those took the car directly to the dealership and left it there kinda. I know there's a recall, but my car is out of the range. Haven't called the dealership yet since I can't consistently reproduce it.

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dgandbver

· #2 · Sep 29, 2014

We have 8500 miles on our QX60 and have not experienced any issue with the brakes as you've described.
Since it's something that appears to be related the brake/ABS system, even if it's intermittent, take it to dealer to have it inspected. A good service advisor or mechanic should be able to diagnose.

mr.smith

· #3 · Sep 29, 2014

It sounds like whatever it is, you are going to have to get it fixed at the dealer. It also sounds like it could potentially be dangerous so I would recommend taking it in to get looked at sooner rather than later.

InfinitiFan

· #4 · Sep 30, 2014

It's going to be best to take it into the dealer, it's still under warranty and something they should be looking after.

Thorin78

Discussion Starter · #5 · Sep 30, 2014

Spoke with the service advisor and going to take it in tomorrow.

He said that "it's supposed to do that" which I found somewhat disturbing that I should feel as if the car won't stop. Even when stopped, the pedal will sink further to the bottom if it did stop mid way. He said that he's replaced the master cylinders for a few other JX/QXs so maybe I'm not the only one.
He did say it's covered under warranty if it needs to be replaced.

mr.smith

· #6 · Oct 1, 2014

So hes replaced it on other vehicles but its also supposed to be like that? Something doesn't make sense to me there. I just can't see why the brakes would be purposefully like that. How would that be desirable from a brake system?

Thorin78

Discussion Starter · #7 · Oct 1, 2014

Seriously right? I think that's the common response from the advisor generally.

This morning he said that he's got another JX where they're replacing the master cylinder right now and if mine needs the same treatment. He called back and said that my brake system had alot of air and they just bled it out. It's a sealed system so I wonder how the air got in.

Hrm.

BobOB

· #8 · Oct 2, 2014

It sounds like it could have been a sloppy installation when he car was built.

Thorin78

Discussion Starter · #9 · Oct 2, 2014

That's a possibility but I only started to notice it in the past 6 months. He told me to keep a look out for it and if it happens again, he's probably going to replace the master cylinder.

dgandbver

· #10 · Oct 2, 2014

Thanks for the update Thorin78.
A bit concerning regarding the quality of components/parts used if indeed it's the master cylinder causing the issues....

Thorin78

Discussion Starter · #11 · Oct 3, 2014

no problem. We've had the car for 2 years now and it's only got about 14k miles on it. And lately I've been driving it a bit more and with the safety features on. I'm wondering if the intelligent cruise control and the collision intervention systems are using the brakes more rather than letting the car manually slow down due to friction or engine brake.

Thorin78

Discussion Starter · #12 · Dec 22, 2014

Well, after taking the vehicle in and repairing the brake issue, it continued to occur. So took it in again and they changed out the brake master cylinder on Thursday. When I got the car back, I immediately noticed the same thing happening and to me that meant the issue wasn't fixed. Long press to stop the vehicle and sinking brake pedal at a full stop. They've got the car now again and is looking into a controller issue.

More to come.

mromm

· #13 · Jun 17, 2016

Same Issue - Epilog

2013 JX35. Same situation with brakes.

1. Pedal intermittently loses pressure when slow speed stops.
2. Pedal goes close to floor at complete stop with light pressure.
3. On several occasions, it triggered the seat belt restraints which was scary.
4. Noted "air sucking" sound from brake pedal. Sounds like "Tin Man" gasping for air.
5. Brakes would "pump back" to normal if I took my foot off brake and repressed.

Car had just over 60K miles. Front and Rear brakes were replaced by dealership about 10K miles ago, no problems there. Brakes lines, caliper seals, obvious stuff checked out clean. But...there was definitely a leak somewhere in the system, just nothing obvious.

Went back to dealership. First attempt at repair resulted in Master Cylinder replacement. Seemed to be OK for 2-3 days. After that, same behavior and noise from pedal.

Second time back, they kept car for a couple days. Ultimately told me that problem was narrowed down to internal leak inside ABS Actuator. No codes just internal leak. They could physically hear a "hissing" sound. They replaced the part.

Service manager took car and drove it himself around for 2 days. Told him I wouldn't put my family back into car unless he would put his!

So far, no noise from brake pedal and brakes again feel firm with low speed stops. We'll see how things go for the next 30 days.

The Infiniti Dealership in Maryland (JBA) where I purchased and service the car was very good to work with. While the problem was intermittent, it was ultimately reproducible. The full retail price of the ABS Actuator repair was approximately $3,000.

If there is another chapter, I'll update this post.

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Reactions: 1

InfinitiFan

· #14 · Jun 17, 2016

Wow, that alone is a lot to go through, too bad as a customer you have to go through those lengths just to see the problem resolved. But at least in the end it seems you're in the clear for now.

Thorin78

Discussion Starter · #15 · Jun 20, 2016

So back earlier this year in 2016, #3 happened to me as well and when I took it into the dealership for an oil change/recall, I mentioned the same thing to them. They looked into it and yup, ABS. Thank goodness for warranty.
I've got less than 26k miles on the car, 2013 model. The seat belt tightening happened again a few weeks ago but not as regularly as before. The brake hasn't been soft however. I might be buying that extended warranty to cover another 3-4 years.

jcristof

· #16 · Mar 29, 2017

My QX60 is having the exact same issue, but our Infiniti dealer is refusing to consider replacing the ABS actuator and instead keeps trying to find other (cheaper) solutions to the problem. We've been going back and forth for months, and they've had the car in the shop at least 5 times, but the issue persists.

I was wondering if you could share with me the contact information of the service manager you worked with to resolve the problem, so that I can have mine reach out to them to get some information on how they diagnosed the issue and got approval from the factory on replacing the ABS actuator under warranty.

Thank you!

transfan0186

· #17 · Aug 19, 2017

I'm having the same issue with my brakes on my 2009 FX50. Just replaced fluid with squeeze pump. Not very hard to do and provided a hard pedal or so I thought. When I push the brakes slowly it will go all the way to the floor without stopping the vehicle. Will pump back up with one quick push. I noticed that the master cylinder brake cap has a hole in it. Has anyone tried just replacing the brake cap with success? I'm thinking wondering if Nissan owners have the same issues?

Marc

· #18 · May 1, 2019

This is my third time to take my Qx60 to the dealer for the intermittent soft brakes and they keep on saying it's normal and they can not reproduce the intermittent soft brakes. It started in 2017 and it's the same issue over and over but it's a safety issue and Infiniti hasn't done much. Please help. I need your suggestions and opinion. Thanks.

Kin424

· #19 · Jul 20, 2020

Did these issues ever come back? We need to remedy the same problems. Just don’t want to throw down 3k if it isn’t the long term solution.

Mitch

· #20 · Sep 10, 2020

mromm said:
Same Issue - Epilog

2013 JX35. Same situation with brakes.

1. Pedal intermittently loses pressure when slow speed stops.
2. Pedal goes close to floor at complete stop with light pressure.
3. On several occasions, it triggered the seat belt restraints which was scary.
4. Noted "air sucking" sound from brake pedal. Sounds like "Tin Man" gasping for air.
5. Brakes would "pump back" to normal if I took my foot off brake and repressed.

Car had just over 60K miles. Front and Rear brakes were replaced by dealership about 10K miles ago, no problems there. Brakes lines, caliper seals, obvious stuff checked out clean. But...there was definitely a leak somewhere in the system, just nothing obvious.

Went back to dealership. First attempt at repair resulted in Master Cylinder replacement. Seemed to be OK for 2-3 days. After that, same behavior and noise from pedal.

Second time back, they kept car for a couple days. Ultimately told me that problem was narrowed down to internal leak inside ABS Actuator. No codes just internal leak. They could physically hear a "hissing" sound. They replaced the part.

Service manager took car and drove it himself around for 2 days. Told him I wouldn't put my family back into car unless he would put his!

So far, no noise from brake pedal and brakes again feel firm with low speed stops. We'll see how things go for the next 30 days.

The Infiniti Dealership in Maryland (JBA) where I purchased and service the car was very good to work with. While the problem was intermittent, it was ultimately reproducible. The full retail price of the ABS Actuator repair was approximately $3,000.

If there is another chapter, I'll update this post.

So OP here providing an update. It is now 2020. The original brake issues I detailed occurred at 60K files. I now have just under 120K miles on same vehicle. The soft brake issue has just reappeared. I took the vehicle back to original deal which has performed all the service since the car was new. This time, within 2 hours, they reported a "C1" (I believe) code indicating a problem with the ABS Actuator. They have one in stock and repair costs will be $2,000. I don't think I'm going too far out on the limb here when I say the lifetime of the ABS module is 60,000 miles. I've also noted that Nissan has recalled ABS actuator modules in later models due to safety issues (internal leaks which could lead to shorts, etc.) Other than brakes, the car has served me well...

1 - 20 of 23 Posts

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