3 months ago I was involved in a major accident driving a loaded Daewoo Avia and the brakes totally failed! There was absolutely nothing there as I was continually pumping the pedal. I was coming down an incline (slip road off a dual carriageway) and hit a car coming from the left on the T-junction at the bottom. As I had no barkes I tried to turn the lorry but of course it turned on to its side. Fortunately we all walked away with cuts and bruises only! VOSA have tested the brakes and have said there’s nothing wrong (i.e.there was air in the system and the brakes applied when tested). I know there was no brakes as I was in the cab!! Has anyone experienced an intermittent brake failure like this and can give me any ideas as to the possible cause? The brakes were working ok prior to this accident.
Hi Hopeful
welcome to TruckNetUK 
can’t really help with your brake problem, sorry, unless it was brake fade causing the problems, had you just come down a hill and been using the brakes a lot ?
Denis,
I’d been travelling steadily along a dual carriageway so hadn’t used the brakes for quite a while, then came off at the slip road which had a downward slope. I naturally took my foot off the throttle and applied the brake and that’s when I realised that there was nothing there at all. Pumping the pedal also gave me nothing.
If you can spread the word around to your mates i’d appreciate it as the police are talking about prosecuting me for driving with undue care and attention would you believe!!! I want to know if anyone else has experienced such a major failure or knows of anyone who has - for obvious reasons. Blowed if I’m going to take the can for this…
I’ll move this to the PDF to see if anyone else has any ideas
Did you use the secondary brake?
I never actually believed drivers who say air brakes failed em but my other half had it happen once so yes, I now know it can happen. Luckily he did not hit anything so all was well.
He pulled the handbrake on and it stopped the truck. That usually works and is usually the first thing to try after brake pedal fail. They run on a seperate system so it is highly unusual for both footbrake and handbrake to fail in one hit.
Also whacking it into a lower gear can help.
On most the hand brake operates as the secondary brake.
It could be caused by moisture in the system. If it hasnt been drained down in a while condensation builds up in the tanks and when the brakes are operated the air coming out at high pressure makes it freeze and blocks valves. Once the vehicles been standing for a while the ice melts and the brakes are fine again.
I had the opposite happen, with the brakes coming ON suddenly and with no warning, causing a full-on jackknife on the M40. 
At the time, the Ministry found no fault on the wagon (although witness statements and police reports exonerated me completely, as it was perfectly obvious that this was a case of catastrophic failure) but further investigation by a guy who had the same thing happen to one of his revealed what he thought appeared to be a manufacturing fault in the Bendix handbrake valve.
Whilst this was obviously not the case with you, a bit of lateral thinking and a further inspection may give you a similar vein of answer… 
(Italics as the man concerned has now passed away so for obvious reasons I have way of corroborating his findings. )
is your Breakadjusted that Wheel runs not free?
were posible that in that Case Break overwarms and Breakfluid changes to Gas
hopeful:
3 months ago I was involved in a major accident driving a loaded Daewoo Avia and the brakes totally failed! There was absolutely nothing there as I was continually pumping the pedal. I was coming down an incline (slip road off a dual carriageway) and hit a car coming from the left on the T-junction at the bottom. As I had no barkes I tried to turn the lorry but of course it turned on to its side. Fortunately we all walked away with cuts and bruises only! VOSA have tested the brakes and have said there’s nothing wrong (i.e.there was air in the system and the brakes applied when tested). I know there was no brakes as I was in the cab!! Has anyone experienced an intermittent brake failure like this and can give me any ideas as to the possible cause? The brakes were working ok prior to this accident.
yes m8 it happened to me. i drive a daf 45 7.5 tonne i was travelling down an A road in st.austell where there was rounabout after roundabout so lots of braking, i only just managed to stop before hitting the car in front of me but i did stop! then a fella in the car next to me pointed out that my wheel was smoking so i pulled over cooled it down with water drained the air tanks and since then not a problem so keep thinking about the weather and think have you got to drain your air tanks
About 1990 ish I had a similar experience in a brand new Seddon Atkinson Ref No H269DGR (Wonder why that reg sticks in my mind 
)
Anyway I’d come down a steep hill from Whickham to Swallwell and as I was fully loaded I had used the brakes a lot, I travelled along towards Blaydon and a coach was parked on the main road opposite the swimming baths, but as I pulled out to pass travelling about 25mph a car appeared around the corner and I had to pull back in, and found no brakes 
Rather than risk a head on with the car I decided to take out the back of the bus 
Anyway, the truck was tested and found to have a perfect braking system, despite my protests I was given a written warning as there was no tacho in to prove my speed (It was a refuse Truck)
2 months after my accident the sister truck suffered exactly the same type of brake failure Reg No H270DGR Luckily there was no accident and he radiod in for the Supervisor to come out straight away, he arrived within 5 minutes as it was close to the depot and the driver pulled away with the supervisor in the cab, he then litterally stood up on the brakes and nothing happened, the brakes totally failed.
Instead of having the truck emptied like they had done with mine, they towed it fully laden to the workshops in Gateshead and Seddon Atkinson sent an engineer out the following day, they spent a few hours running it on a rolling road in the workshops until the fault appeared, upon inspection they found that the Wheel Hubs all had tiny cracks which expanded during braking eventually to the point there was no braking available, in the meantime my truck had only just returned from major repairs and they recalled it into the Workshop to find that the Wheel hubs were exactly the same.
Without a doubt it would of happened again at some point, Seddon accepted responsibility and my written warning was revoked and I was fully exonerated from all blame, so it might seem silly, but get them to check the hubs as a possible cause of brake failure.