Can anyone tell me how the brakes on this truck should feel, it’s a 2004 580 6x4 on disc brakes all round with EBS.
I feel the braking power is lacking, it has new calipers, pads and discs are fine. All those parts were renewed due to fact that the brakes are weak, but their no better now.
Surely these brakes should send you flying out the windscreen when they are touched, but no, it’s like I press pedal,press some more press a little more. That is not EBS!
You aren’t giving anyone much to go on, as a new poster you aren’t even mentioning what driving experience you have. Are we talking about unit solo, empty skelly, empty flat, empty fridge, 1/2 load or 44 tonne? Yes the pedal does need a shove, but if you are unhappy then you need to get a fitter to drive it or brake test it. After completing the work mentioned someone has presumably signed it off as roadworthy especially since it has been defected for poor brakes?
Need to really get someone to put a gauge on a test point at the chambers and work back. Could be a load sensing problem or foot valve/pedal.
What you got to remember is that air bag pressure controls service line pressure.Same idea as old load sensing.
Front axle pressure is set at 1 to 1 eg inlet pressure to outlet pressure but rear axle pressure can be as low as bag pressure (20 psi) this also controls mid axle brake pressure.But as front of tractor dips the rear rises and reduces bag pressure even further so virtualy no rear axle braking.
Now you would think that front pads/shoes would wear out first but the strange thing is that the rear brakes wear at nearly twice the rate of the fronts.Can only suppose its due to imposed king pin weight(although rigid vehicles also wear rear pads at the same rate)
So if your running light the only axle doing the work is the front and the pedal will feel “soft”.What makes it worse is that an empty trailer is hardly applying any retarding force as they also only apply air bag pressure to the chambers as they run through the same sort of load/brake ratio.
Bking:
What you got to remember is that air bag pressure controls service line pressure.Same idea as old load sensing.
Front axle pressure is set at 1 to 1 eg inlet pressure to outlet pressure but rear axle pressure can be as low as bag pressure (20 psi) this also controls mid axle brake pressure.But as front of tractor dips the rear rises and reduces bag pressure even further so virtualy no rear axle braking.Now you would think that front pads/shoes would wear out first but the strange thing is that the rear brakes wear at nearly twice the rate of the fronts.Can only suppose its due to imposed king pin weight(although rigid vehicles also wear rear pads at the same rate)
So if your running light the only axle doing the work is the front and the pedal will feel “soft”.What makes it worse is that an empty trailer is hardly applying any retarding force as they also only apply air bag pressure to the chambers as they run through the same sort of load/brake ratio.
If you think hard about the (obvious) difference between a front axle and a drive axle I’m convinced a chap of your intellect can solve this brake wear riddle. 
Here’s a clue though, what do drive axles have twice as many of?
brake chambers I would think
Enlighten me?
Here’s a clue though, what do drive axles have twice as many of?
[/quote]
SIR SIR SIR !!! Is it wheels ■■ 
Bking:
brake chambers I would think
Enlighten me?
really 
do drive axles have 4 brake chambers
Truck has had no load on it so far,it was suppose to go get a 46 ton all up of logs on it, it draw a timber skelly.
The thing is that on way to get this load it could not manage to stop its self empty let alone with 46 ton all up.
The retarder is not working either… this was working when truck was bought .
ABS light is on when started,but if you restart truck it goes out. The ABS light will be out when driving ,but brakes are bad and no retarder…
Get a brake test with the vehicle fully loaded with it’s trailer as a start point…Then from there if it fails you will know what wheels /axles are at fault…
sounds like an ebs fault to me, you only need a broken wire and you can loose most of your braking
Moose:
sounds like an ebs fault to me, you only need a broken wire and you can loose most of your braking[/quoteHe would have a warning on the dash if it is an ebs fault
we’ve had intermittent faults when driving in both Volvo and daf regarding ebs and broken/damaged wires, in all cases the truck has taken some stopping, though I was not driving so cannot report on warning lights
the scanias as yet have not had this problem, though the brakes are in all cases no where as keen as daf,volvo,merc
you could say the pedal in a scania has a spongy feel
Moose:
we’ve had intermittent faults when driving in both Volvo and daf regarding ebs and broken/damaged wires, in all cases the truck has taken some stopping, though I was not driving so cannot report on warning lights
the scanias as yet have not had this problem, though the brakes are in all cases no where as keen as daf,volvo,merc
you could say the pedal in a scania has a spongy feel
When you get the red warning on the DAF ,it is brown pants time …If no warning I reckon a loaded brake test is the best option ,as it should show up ineffective brakes
argosy2006:
Truck has had no load on it so far,it was suppose to go get a 46 ton all up of logs on it, it draw a timber skelly.
The thing is that on way to get this load it could not manage to stop its self empty let alone with 46 ton all up.
The retarder is not working either… this was working when truck was bought .
ABS light is on when started,but if you restart truck it goes out. The ABS light will be out when driving ,but brakes are bad and no retarder…
I haven’t sat in a Scania for a couple of years now, but IIRC the retarder works when the brake pedal is applied. There is a switch on the dash to turn it on or off.
green456:
Bking:
brake chambers I would think
Enlighten me?really
do drive axles have 4 brake chambers
Think so when its a 6X4
Think the “4” is a clue.