Hi. having problems with the trailer brakes coming of slowly when the unit park brake is released. have heard that it could be the trailer release valve on the unit, can anyone give me an idea of the location of said valve on a renault premium 2007 6x2
ta john.
I remember driving a couple of old Premiums that used to do this. It was the pre Volvo versions though. Never had it happen on modern ones.
Don’t use the park brake till you park up lol
Hi
definatly trailer release valve on the unit, realy easy to replace yourself it sits on cross member almost under fifth wheel
john
It’s on the cross member right behind the gearbox - The air dryer unit is just behind it. The pipes have red marker rings on them.
Steve
thanks for the help will get it replaced
What the hells a trailer release valve?
Air is fed down red line to the quick release valve to drop the spring brakes on the trailer
Hand brake is fed via service line (yellow) to apply park when coupled to a tractor.
When a trailer is coupled to a tractor the spring brake is out of service.
Sounds like you got a kinked yellow line as the trailer brakes exhaust ,on service,through the the tractor foot valve,as the yellow line is only a signal to the trailer control valve.
Before “my honarable friends” correct me .The signal pulse exhausts through the tractor the actual chamber pressure exhausts through the brake control valve on the trailer.
Had a few gray & adams trailers lately with mavis rails that either kink the red so you cant get the springs off or yellow so that once brakes applied they lock on.
Or could be a worn release pin in the service coupling(the three pronged self seal valve in the male “c” coupling from the tractor).This would allow air in but a slow exhaust causing brake lag.
For sake of clarity Renault call it the trailer control valve but most of us knew what was meant 
The O.P only asked where it was located.
Yes he can locate it,pay 500 quid to change it and it wont make the slightest bloody difference,when he could have spent 15 quid for a self seal valve and a C coupling and got a result!
Bking:
Yes he can locate it,pay 500 quid to change it and it wont make the slightest bloody difference,when he could have spent 15 quid for a self seal valve and a C coupling and got a result!
Rubbish.
i had the same problem handbrake releasing realy slow changed the said valve cured the problem
Bking:
Yes he can locate it,pay 500 quid to change it and it wont make the slightest bloody difference,when he could have spent 15 quid for a self seal valve and a C coupling and got a result!
You seem to know a lot about the trailer release valve considering your last post you didn’t even know what one was 
Bking your sort of right. When you press the brake pedal the foot valve sends a signal to the trailer control valve, which sends a signal to the ra4/6 valve on the trailer which activates the chambers and applies the brake.
When the pedal is released, the trailer chambers release through a quick release valve, the air from the ra4/6 valve back to the trailer control valve releases at the trailer control valve on the lorry and the air from the trailer control valve to the foot valve releases at the foot valve.
The above is the same for the handbrake, just sub handbrake valve for foot valve.
The symptoms sound like the air in the yellow line from the ra4/6 valve back to the trailer control valve in the lorry is too slow to release.
Therefore I would also say faulty trailer control valve, located more or less at the back of the gearbox,
Bking:
Yes he can locate it,pay 500 quid to change it and it wont make the slightest bloody difference,when he could have spent 15 quid for a self seal valve and a C coupling and got a result!
There would, most likely, be symptoms with service brake application if this were the case though also. I don’t think you’d be looking at anything like £500 if he changes it himself unless there’s some more expensive part on newer Renault models these days.
The ‘what the hell is?’ question could be asked of almost endless made up terms you’ve posted. I seem to recall a predominance valve on a trailer somewhere as a fairly recent contribution.
So you dont know why you have a predominance valve on a trailers air tanks?
Dear me!
Simple way to test wether its the self seal valve or trailer control valve that holding the signal is remove the self seal unit.
And as for the service side of the chambers exhausting through the quick release valve.
What a load of twaddle.
While we’re at it, what happens when a diesel runs away on it’s engine oil. I’ve heard that’s impossible. 
Bking:
So you dont know why you have a predominance valve on a trailers air tanks?
Dear me!Simple way to test wether its the self seal valve or trailer control valve that holding the signal is remove the self seal unit.
And as for the service side of the chambers exhausting through the quick release valve.
What a load of twaddle.
Can’t be bothered, everything you post is ■■■■■■■■. There is literally no single part of a truck and trailer combination that you properly understand how it works.
It has been demonstrated time and again that you do not have the experience, knowledge or ability to offer any real advice but insist on trying to effectively shout down plenty of people who do.
peterm:
While we’re at it, what happens when a diesel runs away on it’s engine oil. I’ve heard that’s impossible.
At last your learning.
Now why do you have a cam position sensor bright eyes?
Own Account Driver:
Bking:
So you dont know why you have a predominance valve on a trailers air tanks?
Dear me!Simple way to test wether its the self seal valve or trailer control valve that holding the signal is remove the self seal unit.
And as for the service side of the chambers exhausting through the quick release valve.
What a load of twaddle.Can’t be bothered, everything you post is ■■■■■■■■. There is literally no single part of a truck and trailer combination that you properly understand how it works.
It has been demonstrated time and again that you do not have the experience, knowledge or ability to offer any real advice but insist on trying to effectively shout down plenty of people who do.
Yes dont be botherd sick of hearing amatuer bull from “experts” like yourself.
peterm:
While we’re at it, what happens when a diesel runs away on it’s engine oil. I’ve heard that’s impossible.
So how come if you put petrol in a diesel engine fuel tank it wont er go.
Petrol is more flammable than crappy old engine oil but for some reason the old diesel motor just cant be assed running anymore even when you inject it at the right time!
odd eh!