DAF 45 lorry brakes not locking out on roller test?
On hgv test brakes not locking out on footbrake. Hand brake OK. All pads linings like new. All cylinders working correctly. No air in hydraulic system or leaks. Air at 9bar with no leaks. Wheels lock out on road test perfectly. Lorry is short chassis with horse box attached and paper history shows it has always only just passed the brake test. It is only failing by 2 per cent this time BUT ENOUGH TO FAIL!
having problem with my 45,new shoes new drums, still failing by 2 or 3 %. told by a lorry mechanic to drive down hills with handbrake on to bed in properly . dont be afraid of getting them too hot, do this for a few days an hour or so each time and the performance will be noticably better-- and it works
allen
January 2011
I also had a brake problem as mentioned below, i have now replaced the footbrake valve, brakes locked out and passed test, have never come across this problem before, there must be a leakage within the foot valve when holding half way then when pressed fully full air is not going to master cylinder
Martin
July 2010
Where is the load sensor? Is it connected with the air suspension? Our 150 has failed its brake test and yet normally its brakes are really good. The garage tell me it doesn't have a load sensor.
susie
July 2010
When you say brake valve replaced do you mean the footbrake valve as i have exactly the same problem at the moment
Martin
May 2010
does the load sensing valve just need a tweak on the connecting rod?
tony wilde
May 2010
Re fault in brake valve. This has been replaced and the wheels now lock on the roller test at the HGV station and therefore it has passed. I have never had such a fault on a lorry before. Air leaks yes but not one which only appears when the pedal is held half way down.
Thanks for suggestion about weight in back and will do at next test.
kett
November 2009
I know this is not an answer to your problem but get some weigh in the rear over the back axle, as when i take any trucks for the test i all way stick at least a ton over the back axle.
john
November 2009
Re daf 45 brakes. The hgv roller test requiries the footbrake to be held approx. half way down for about 30seconds before applying full pressure. We have now found when the brake pedal is held half way down an air leak commences at the brake valve. This appears to prevent full pressure getting to the brake air servo unit. We are going to change this and I will report further if its cured. Unusual fault.
kett
November 2009
I can answer this question...
DAF 45 lorry brakes not locking out on roller test?
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