Hi,

I just wanted other drivers to be aware that this has happened again...

The driver (my brother) was traveling at 100 km on a highway when the traffic stopped ahead of him (me and other traffic); he applied the brakes to reduce speed to 25 km aggressively, the brakes worked as designed. Without lifting the brake pedal he pressed further to bring the car to a complete stop (more aggressively). This is when there was no speed reduction; he said it felt like the brakes went soft, he felt a couple of thumps, like the anti-lock trying to work but the car was not de-accelerating. He panic braked (floored the pedal) and the back brakes locked up and he narrowly avoided rear-ending me.

We pulled over at a nearby service station and inspected the brakes expecting to find a line leak but the brake reservoir was full and no leak could be found. My brother understandably did not want to continue driving my car at this point. I tested the brakes to make sure I still had positive brake pressure and turned off the VDC and drove the rest of the way from Montreal to Toronto without incident.

My brother does not ride the brakes and he is a very competent driver and we both have experience with wash-board road surface anti-lock brake failure and understand that situation well, the road service was not perfect but not suitable to cause the issue. The weather was 13 c with dry roads and the car was loaded with under 500 lbs including driver and passenger. Tires are winter with medium wear on the treads, the condition of the car was; compression rod (passenger side needs to be replaces; knocking), brakes rotors re-surfaced last pad change (front and back) and had developed a ridge on outer diameter, all pads at approx 60% wear, AIR-BAG Warning Lamp on and the Check Engine Warning Lamp intermittent due to rust in the filler neck of gas tank.

The next morning I had a brake job done with new pads and rotors all around. I told the mechanic what had happened so he did a complete inspection. There were plenty of pads left on all sides and the rotors were worn out (not to a dangerous level in his opinion), the brake fluid was full and there was no heat scoring of the rotors so he doubts that the brake fluid was boiled. There was a lot of surface rust around the master cylinder but they moved freely when he compressed them.

There has been no source of the problem found at this time.

My plan is to have the Brake Master Cylinder, Brake Booster and the Vacuum Lines (especially the check valve) inspected / serviced. My car has 240k on it now and my confidence has been somewhat diminished. I have now changed my driving style and I’m always concerned about this failure reoccurring, my wife will no longer drive my car (her choice) and is reluctant to be a passenger. If I cannot find a root cause soon then I will have no choice but to replace this vehicle, a sad prospect to say the least as I was quite fond of this car. I will do a follow post of the outcome, the car will be serviced by Simone Performance Imports (SPI) so I know I will have the best people working on this.

 

240K is 149,000 mile way past the 100k design point. Common to totally rebuild brakes especially caliper piston seals prior to this mileage.

 

When was the last brake fluid flush?

 

To answer Q45tech and TwilightBlue; I had a complete brake overhaul done ($1800 CAD) by Alta Infiniti back in 2006 around the 160k (km) but I must admit that I do not remember what they did totally, but the brakes were perfect (for a while) after they did the job.

I’m also learning that these cars are different, my wife’s previous cars, my friends and all my parents’ cars ran for 10+ years without any major brake repairs nor was there any “life-span” on the brake system. I rebuilt the brake system in 06 for the simple reason that the brake systems on these cars are crap. The brake ware problem is well documented and I’ve lived through it firsthand (but I still love my G, I just hate the corporate response BS).

I will change the caliper seals and flush the lines right away.

Correction to my previous post; I meant the rust was around the caliper pistons not the master cylinder, I guess most knew what I meant.

 

In 3 years, you could have lowered the boiling point of your fluid to the temp that could have easily been achieved by that panic stop. 03s come with the smallish 11.5" front rotors and aggresive pads. IMHO, that's alot of heat transfer to the fluid. Introduce enough moisture to the brake fluid and IMHO, it will boil long before the rotors show any signs of fade.

When I ran my pads too far down, the brakes would fade by the time I got down to the bottom of a big hill. (on my old maxima)

Flush your fluid with a QUALITY brake fluid (not the race stuff, it's too hydroscopic) and test again on a section of road that's clear.

 

I replace brake fluid every 2 years at a minimum, and replace pads (and sometimes rotors) when more than 70% worn since worn pads transfer more heat to the caliper and thus the brake fluid. As Jeff pointed out, 3 years is plenty of time on brake fluid, especially with the kind of mileage you've put on the car.

Also, you mentioned you never rebuilt brakes after 10 years, but was there similar mileage on those other cars?