Almatti

I have my M in at the dealer. I sensed and comlained about a variable Spongy Brake pedal to my original dealer soon after I got it in June. In fact I experienced a couple of No Start issues. I do have a dealer installed Remote Start installed. That was checked out 2X. A few months ago, they adjusted the brake pedal switch. I haven't experienced the No Start since. But sometimes when I start the car stepping on the brake and hitting the start button, the pedal is hard, other times it's softer???

Now I brought my car to a different Dealer, they listened to me, (Greenwich Infiniti - the dealer I leased the vehicle; I brought the cat to Pepe Infiniti), and have ordered brake lines and other parts that are on "back order". I'm in a G37X loaner for a week - waiting for my car.

PS....I feel the brake pedal overall is too spongy - a little too soft. The G has a much better feel. We'll see how these repairs affect the feel or is it just BS to get some warranty money for the dealer.

2008G-Man

The M is not a G .... or the G is not a M, I have both and the brake pedal is a little stiffer on the G than the M but the M stops just fine.

Almatti

I have a G Loaner for the past 2 weeks. My M37X is at the dealer. They are installing a brake hose and adjustment switch. They say that their tech did sense a little sponginess in the pedal too. The work is being done under warranty. You may be right about the differences in the braking between the G and the M. Maybe the dealer is getting Money for Nothin.....Chicks for Free.
My original dealer (Greenwich Infiniti) adjusted the brake pressure switch, but the other dealer (Pepe Infiniti - supposedly the largest volume dealer in the world), has decided to replace the parts. I'm waiting 2 weeks already. It should be ready this week. The havoc in Japan probably has something to do with the parts delay. By the way, NONE of the Media outlets talk about the crisis in Japan since the Tsunami and earthquake. Their Nuclear Power plant is spewing 72K gallons of radioactive water into the sea of Japan everydy !!! They can't stop it. Check out the web on it. Dead & Radioactive laden fish are turning up on the West Coast of the US......

2008G-Man

Hope they can fix it for you .... there are a lot of sites posting information regarding the Fukushima's Radioactive Water Leak, lots of it false, lots true. If you want to read a factual article that takes political agenda out of the equation, read Nation Geographics.

Fukushima's Radioactive Water Leak

Almatti

Getting back on point......I got my car back from the dealer yesterday. The brake pedal is better, a bit more firm, less spongy. They replaced a Brake Booster Hose that had a slight leak in a valve....Under warranty. Pepe also administered a Wheel Alignment and Balancing of the wheels (according to the Service adviser) , applied minor software tweaks, and cleaned the throttle body - No Charge.... After close to 3 weeks in the shop waiting for this part, and driving a G37X, I realized how much I missed my M. She is really humming now !! Smooth, comfortable, a really responsive. Man she likes to go....I hit 80 mph like nothing.

Almatti

I'm still experiencing a Varying : Firm to less firm Brake pedal. Dealer has replaced the Brake Switch 2X. I'm also getting a squeal on Passenger front brake when coming to a stop with warm brakes. Picked up the car on Monday, after dropping off on Friday past, Service Advisor said they lubricated the suspect brake - after picking up the car, it returned again later that day.

I'm scheduling a Bring Back for: the Varying pedal effort (at startup the pedal will be firm and then after starting it can go to the floor. Start up later and the pedal feels different), and the brake squeal. I will test drive with a Tech this time. NOTE: I do have the Remote starter installed which was a Dealer Installed item. The RS does tie into the Brakes, I think. The older RS did, now it cuts out after you open the Driver door after 3 seconds. The older models of RS (pre- 2013) cut the engine when you stepped on the brake pedal to shift the car out of P to D.

Almatti

An UPDATE: Returned the car to the dealer last week. They Bled them thoroughly, replaced the brake fluid and does seem a little better. They informed me that there may have been some air in the system?? They still don't feel as sound and firm as the loaners I have driven. And I still have a brake squeal that they have not been able to eliminate. I am a PIA when it comes to stuff, but hey, if you look at the G forum Transmission Updates Thread (Almatti) entries over the course of 3 years, you will see that I was a "leader" in the complaints dept. about the lagging 7AT. You pay good money and I want the car to perform as it should.
Next week i will return it again for another look and this time go and drive another M37X to compare.

Almatti

As of Today and after multiple trips to 2 Dealers, I still experience the same thing: a Brake Pedal that Just does NOT feel as firm as it should. Just last week, brought the car in for Service to my Dealer, had a 2014 or 2015 Q50 as a Loaner, the brake pedal is so much better in the Q. That was the same with all the other loaners I had over the past year. Greenwich Infiniti, my leasing dealer actually was annoyed when I complained to them some months ago. The Service Manager said that their Service dept and the "other " dealer (Pepe Infiniti) has checked and analyzed all aspects of my complaints - and other than flushing the brake fluid - can't confirm anything is wrong.
I insisted then and again this week, There is something NOT right. None of the dealers have let me drive another M to compare, but I've had 3 different Q50s, The late model SUVs (Q60?) - all have a solid brake pedal feel.

What happens at times is this: Stepping on the brake pedal at cold startup - the pedal is hard , then as the car starts, it goes soft almost to the floor. Other times - it feels differently, more normal.....When driving, it is definitely more "Spongy" than than the loaner cars. Very Frustrating. The brakes are grabbing but just feel so different. I Think it has something to do with the Electronic Brake Force system - when you apply a steady application to the brake pedal, this type of feature is supposed to enhance the braking by continuing to more firmly apply the brakes. Try it....when coming to stop, you will feel the brakes being applied more actively as you come to a top with an even application on the pedal. It's a Power brake Enhancement that many cars now have.

I don't mean to be peculiar, but I do insist to have my car work exactly as it was engineered. We all pay lots of money for these rides. It's reasonable to have that. I will say, Other than this issue, the car is terrific (handles and rides very well, gives the right amount of Sportiness for this size, comfortable, roomy, beautiful interior). It's a shame that not many on the road by me. Lots of BMW 535s & more Audi 6s....The M37X in my mind is great Value.

JSolo

iTrader: (14)

I wonder if the brake booster has some a leak of some sort. Should be easy enough to test if it'll hold a vacuum or leak down.

SwissCheeseHead

iTrader: (6)

OP, I feel the same way about the little issues with my car. I don't know what your problem is, but I can relate to you're experiencing. Fortunately for you, you are under warranty. I am not. I'm going to go with Jsolo and wonder if there is something wrong with the brake booster. It's still a hydraulic brake system so you would want to follow the normal troubleshooting procedures. Just make sure you cover all of your bases (pads, rotors, lines, fluid, brake pedal etc.).

tech37

Typically a vacuum leak at the brake booster will cause the opposite...a hard brake pedal.

A spongy pedal is usually do to the master cylinder seal leaking.

All the EBD does is balance the braking power to basically eliminate nose dive under normal braking.

Some cars just have a different feel to the brake pedal...my M is different from my QX...same year...

I don't see how they are stopping you from driving another M...just go test drive one...ive never heard of such foolishness by a dealership.

Almatti

tech37, Can you explain the following: upon starting the car, stepping on the Brake, the pedal is Hard, when the engine turns over, it softens and can go virtually to the floor.

My description of a "spongy" pedal is after starting and driving, stepping on the brake pedal yields a Spongy less than hard pedal.....it is NOT the same feeling to the brakes that I had in my 2010 G37x , nor in the various Loaners I have recently driven : Q50s, & QX60s. The brakes have a much firmer feeling than my car. I'm going to insist on a M37X or the new Q70 as my next loaner - asking the dealer for another examination of my complaint. It is curious thoughthat at 2 prominent local Infiniti Dealers, they have not given me M37Xs as loaners ???

tech37

The reason the pedal is hard when you are starting the car is because you don't have vacuum assist from the engine once it starts. You have vacuum as soon as the engine starts. Only two things cause a really spongy pedal...a bad master cylinder or air in the system. Typically if you have a bad master cylinder you might have a good pedal then as you are holding the brakes the pedal starts dropping to the floor. With air you either get spongy pedal or inconsistent brake modulation.

As far as getting an M/Q70 as a loaner...my dealer doesn't have any either...Q50, QX60, QX80....thats about it...but you should be able too test drive either a new one or preowned..

Almatti

tech37, sorry for sucha late response. The description of "inconsistent brake modulation", seem to be the symptom. I had the brakes replaced, and bled of course at the dealer some months ago. The Hard and Softer Pedal variances continue. I am going to try one more time for another review of the situation. I have NOT driven another M37X as a loaner. The dealers always seem to give me Q50s or Q60s - the braking action in those cars are much more of a solid feel to the pedal. One additonal point: the 2013 M37X that I have has a Hill Holder feature - where on a incline at a stop light let's say, if you take your foot off the brake, the car does not roll backwards. On some intermittent occasions, at level road stop, I feel a slight modulation in the pedal.