I have also experienced brake fade to the point of failure, the reason was going down a steep hill too fast in to higher gear. Never blamed the brake fluid. Now I am not saying you were going too fast and not selected the right gear but I haven't yet seen brake fluid fail to that extent. The reason brake fluid fails is it attracts moister and under excessive braking that will boil off causing the fade.
cheers
blaze

Brake fluid is hygroscopic ie it absorbs water. This lowers the boiling point of the fluid dramatically and can cause what happened to you. Two things are wrong in your case.

 

1   Obviously the brake fluid boiled. This was most probably due to absorbing water - see above. It could also be that the service department actually did replace the fluid and that the stuff they used was already slightly contaminated. (I suspect that the fluid was not changed).

 

2   You probably drove down Brown Mountain without using your gears, or at least not using a gear low enough to hold the load without overloading yoiur brakes. I regularly go up and down the mountain and I barely touch the brakes. OK - I am as slow as a wet week, and at times traffic builds up behind me but as soon as possible I pull over and let them pass. I often smell Fried Ferodo from other cars when I get near the bottom of the hill.Two weeks ago, I went down the mountain with my caravan and I used the brakes only on the hairpin bends. I was taught  years ago that if you need 3rd gear to go up a hill, you need 2nd gear to go down it.

 

Regarding point 1 above, years ago my wife's car was going out of warranty and I took it to the dealer for the last time because I service my vehicles myself. Part of the service was to replace the brake fluid (oddly enough not the clutch). When I got it home, I jacked up the car and checked. Sure enough, the bleed nipples still had road grime on them and not a sign of brake fluid. Straight back to the dealer and asked "Did you replace the brake fluid?" 'Yes Sir' was the reply. Some unprintable response from me evoked action and the fluid was replaced whilst I watched it being done. Your experience was precisely the reason I checked it (plus my mistrust of dealer service anyway). Further, water in the brake fluid can cause corrosion of wheel and master cylinder components. leading to ultimate brake failure. Not good. Manufacturers specify change intervals fro a very good reason.

 

These days, your local mechanic probably has a fluid conductivity meter which measures the percentage contamination of water in the brake fluid. Maybe you should get someone to check it and if it is high, go straight back to the  dealer and (politely) tell them what you think...

 

Some years ago, I did a driver training course with the Aust Federal Police in Canberra. Fantastic 2 days. One of the questions I asked was "Modern Falcons, Commodores and Magnas all have 4 wheel disc brakes, so braking on modern cars should be no problem" As usual, I was wrong. The instructors said that brakes on modern cars were OK for 1 stop from 100 km/h. They taught us Threshold braking, where you hit the brakes fairly hard and let the car's nose dive. This loads up the front wheels and once the nose has dipped, then you really stand hard on the pedal and wait for a wheel to lock up. As soon as it does, you ease off the pedal slightly until the wheel starts turning again and then load up the pedal again. The stopping distances possible are amazing. Then, they got us into a standard VP Commodore and we started practising threshold braking. After one stop from 80 km/h, it was back up to speed and repeat the process over again. The second stop had the pedal a bit spongy and the third stop the pedal was on the floor. OK - anyone who drives like that deserves to crash into something, but anyone who drives hard down Brown Mountain relying on their brakes is doing similar stuff.

 

I am not criticising you for running out of brakes - you were probably not aware of the limitations of your vehicle and the road conditions ahead - but it serves as a warning for others to watch out in similar conditions. Well done for alerting everyone to the problem.

Overheating of Brake Disc Pads can be a cause of Brake Failure as also can Overheating Of Brake Fluid that has Absorbed too Much Moisture as it is Hygroscopic. The Contamination of moisture in the fluid as Blaze says causes the Moisture too Boil causing Air Bubbles in the Brake Fluid which then contributes to Loss Pedal. Therefore a Braking Failure. In FAR NORTHERN parts of Australia with High Temps plus Excessive Humidity it pays to Flush Brake Fluids More Regular.

Cheers Kev.

Hi

No need to test the fluid just CHANGE IT. Easy to do and the fluid cost is stuff all. If you do any water crossings then change it soon after as well. Cheapest insurance you can do ! From my observations most fluid is never changed despite the schedule, until some failure forces it. When the pads are changed do not force the fluid back but open the bleed and take the old stuff out as the piston is retracted. 

jaahn

I might get the air in my tyres tested too, can't be too careful eh... Actually, it should be OK cos I only use Caltex air in my tyres.. I've heard about the shonkey additives from other places.

-- Edited by 03_Troopy on Monday 15th of February 2016 09:35:27 PM

Bugger, I didn't know about the racing air

I was more interested in getting people to have the brake fluid in their tugs tested and, if necessary replaced than in finger pointing exercises.

Yeah, everyone has 20/20 hindsight but that's not helpful when you're confronting this situation in real time.

No, we hadn't slipped into sports mode and locked the gearbox into 1st gear; yes we tried using the manual over ride on the the brake controller with no effect; yes we tried using the park setting on the gear box (with no success); no we don't have a trusted mechanic because we are on the road full time (which is why we use the manufacturers service agent).

While the decision not to shift into manual impacted of the brake failure, contrary to the opinion of some (blaze, Peter), the guy that actually got his hands dirty replacing the brake fluid explained to us that the poor condition of the brake fluid also contributed to the failure.

So next time we're confronted with a steep descent we will slip from automatic to sports shift and lock the ute into low gear. We will also replace the 10" brakes currently on the van with 12" to provide greater braking capacity; but just as importantly, we will be monitoring the condition of our brake fluid more closely in the future as we recommend you do as well.

Regards

Dave

Perhaps the Brown Mountain was named for the colour of the underpants of people descending

 

The Phantom

Hi Dave
Like I said first up I have also done the same. I have been in the trade for 40 years and have seen brake fluid that black and contaminated that its nearly a solid thing and it hasn't created the problem you describe. Has it created other problems, yes. I think your trusted mechanic has told you what you wanted to hear and not been game to tell you that you were too fast for fear of upsetting a client. We all take the easy way sometimes. My answer has been an honest appraisal of what happened to you and also of my own incident.
I have used water as brake fluid in remote outback because of fluid loss and not carrying spare fluid, it works as a temp fix as does milk. So don't believe all that a mechanic tells you
cheers
blaze