Is it possible for this brake to fail when it’s been applied?
Why, what did your unit roll into■■?
Yes, there was an issue with this a few years back, it may have been MANs it affected but I’m not 100% sure.
My dad had a problem with his 111, parked on a hill and got out for directions. looked back truck rolling back down the hill it stopped when it jack-knifed. Very lucky no other person or vehicle involved. Got some stick from his mates for years after, one bloke always called him handbrake after that. Swears blind he definately put it on properly.
i guess it would be pretty rare, but i suppose anything could fail.
Most unlikely, I would have thought.
The brakes are held on by very strong springs,
so are actually held off by air pressure while the
handbrake is released.
The system is fail safe, if it goes wrong, the vehicle won’t move.
99.999999% of such “brake failures” are caused by someone
either failing to set the brake or inadvertently releasing
it when they shouldn’t have.
Regards,
Nick.
Harry Monk:
Yes, there was an issue with this a few years back, it may have been MANs it affected but I’m not 100% sure.
I remember the issue you are referring to but I am thinking it was Daf’s, CF Daf’s maybe? I remember a few threads on here, maybe the old boards about it.
Coffeeholic:
Harry Monk:
Yes, there was an issue with this a few years back, it may have been MANs it affected but I’m not 100% sure.I remember the issue you are referring to but I am thinking it was Daf’s, CF Daf’s maybe? I remember a few threads on here, maybe the old boards about it.
Could be, I seem to remember somebody posting a link to a report on the technical issues behind the fault and that it involved handbrake levers moving into the release position several seconds or even minutes after they had been applied, and that it happened sufficient times for it not to have been one or two isolated cases of driver error.
Harry Monk:
Coffeeholic:
Harry Monk:
Yes, there was an issue with this a few years back, it may have been MANs it affected but I’m not 100% sure.I remember the issue you are referring to but I am thinking it was Daf’s, CF Daf’s maybe? I remember a few threads on here, maybe the old boards about it.
Could be, I seem to remember somebody posting a link to a report on the technical issues behind the fault and that it involved handbrake levers moving into the release position several seconds or even minutes after they had been applied, and that it happened sufficient times for it not to have been one or two isolated cases of driver error.
Yep, that sounds familiar. I think it might have been Krankee that posted the report now you mention it.
Edited as I found these.
Don’t know if it’s the same thing but about 8yrs ago one guy I know had his DAF Cf wrote of as he was driving along quiet happily the brakes locked on and put him in a ditch(new truck at the time) .
Insurance traced fault to a air line near exhaust burnt thru and air realised and locked brakes on ! Was told there was a product recal on them to fit a small bracket to stop it happening again.
Ps driver was ok but got a hell of a fright !
Interesting reading about the CF DAF, though the in depth report does state that the dust cover was damaged, not badly designed.
I wonder what the full story is behind the original question…
Regards,
Nick
When you put the park brake on on a Volvo, they, for some reason don’t put the brakes on on the trailer, so if the unit is on a slippery surface the whole combi can easily start sliding down the road.
What a stupid bloody idea, can anyone on here imagine a scenario where when they put the park brake on, they don’t want ALL the brakes included.
Yes I know that pulling out the button above the brake lever will also apply the trailer brake but lets face it we don’t all read the owners manual before we drive.
schrodingers cat:
When you put the park brake on on a Volvo, they, for some reason don’t put the brakes on on the trailer, so if the unit is on a slippery surface the whole combi can easily start sliding down the road.What a stupid bloody idea, can anyone on here imagine a scenario where when they put the park brake on, they don’t want ALL the brakes included.
.
This was a problem we used to have on bulk tippers if the load froze in the bucket, as it slid out it could push down on the rear of the trailer and lift the drive axle clear of the ground, the weight of the frozen load and the angle of the bucket would then make the whole lot shoot forward.
Yes.
viewtopic.php?f=2&t=43593&hilit=+hand+brake
I had to change the valve in the end as it really put the wind up me and I was a bag of nerves worrying if it might happen again.
schrodingers cat:
When you put the park brake on on a Volvo, they, for some reason don’t put the brakes on on the trailer, so if the unit is on a slippery surface the whole combi can easily start sliding down the road.What a stupid bloody idea, can anyone on here imagine a scenario where when they put the park brake on, they don’t want ALL the brakes included.
Yes I know that pulling out the button above the brake lever will also apply the trailer brake but lets face it we don’t all read the owners manual before we drive.
The Volvo tractor units have a separate brake for the trailer in the cab, it’s a black pull button thing. I forget the name of it now though.
Edit: think it’s called a “broms” brake, but don’t know correct spelling. One of the resident fossils with know. 
Rob K:
Edit: think it’s called a “broms” brake, but don’t know correct spelling. One of the resident fossils with know.
No worries, a resident fossil got it bang on the money, it’s called a “Broms brake”. 
However, it does not apply the trailer brakes, it simply locks the drive axle brake on if you pull it out for five or ten seconds, or, if you have a leaky tractor unit, it pops out in the middle of the night waking you up and doing the same thing.
ncooper:
Interesting reading about the CF DAF, though the in depth report does state that the dust cover was damaged, not badly designed.
I wonder what the full story is behind the original question…Regards,
Nick
What are you insinuating? 
Harry Monk:
Rob K:
Edit: think it’s called a “broms” brake, but don’t know correct spelling. One of the resident fossils with know.No worries, a resident fossil got it bang on the money, it’s called a “Broms brake”.
However, it does not apply the trailer brakes, it simply locks the drive axle brake on if you pull it out for five or ten seconds, or, if you have a leaky tractor unit, it pops out in the middle of the night waking you up and doing the same thing.
Really? 
I’m sure there was some discussion many years ago on this site by the resident fossils and it’s operation is the lock the trailer brakes. 
I stand corrected then. Found some blurb on it here btw : roadtransport.com/blogs/big- … s-ret.html
So the handbrake in the Volvo’s doesn’t lock the trailer wheels then?
Rob K:
So the handbrake in the Volvo’s doesn’t lock the trailer wheels then?
No, and although I am probably disadvantaged in that I have nearly always driven Volvos, I have driven other makes of tractor unit and I am struggling to think of any in which applying the tractor unit handbrake applied the trailer brakes.
Harry Monk:
Rob K:
So the handbrake in the Volvo’s doesn’t lock the trailer wheels then?No, and although I am probably disadvantaged in that I have nearly always driven Volvos, I have driven other makes of tractor unit and I am struggling to think of any in which applying the tractor unit handbrake applied the trailer brakes.
The DAFs do don’t they? If you’re parked on a dusty surface and release the handbrake on XF with a fully loaded trailer attached, there’s a big “chhhhh” noise from the trailer wheels and the dust gets blown out from under the trailer wheels. 