How did you get on with your brake problem. I’m having something similer happening to a 164 2004 4x2. But it feels like both my front brakes are coming on. Iv spent thousands over the last two years on this problem. Scania couldn’t find anything wrong.
Can anyone suggest anything to check.
In the end a new caliper was fitted, which sorted the problem.
The caliper had been ‘serviced/cleaned’ and new pads fitted previously, but a new one seemed to be the cure.
Our X reg Scania rigid has a very annoying problem. About once or twice a week at the moment the front caliper comes on for no reason. The disk and wheel get very hot, pulling the vehicle to the offside, and then after letting it cool down it is fine again.
The caliper seems to work fine otherwise.
Does anyone have any idea what might be causing it?
i had a similar problem on a daf. nearly wrote the thing off as it got that bad that no brakes worked except the near side front and that was either full on or full off. there was a control box above the back axle. that was replaced and all was ok.
All the brakes work fine limeyphil - just occasionally the front offside caliper comes on - it doesn’t even seem realted to the brakes being applied. Thanks for the post though.
I think it could be the return valve …
Smart Mart:
All the brakes work fine limeyphil - just occasionally the front offside caliper comes on - it doesn’t even seem realted to the brakes being applied. Thanks for the post though.
thats just like it was with me. an intermitent fault until it went wrong in a big way. one really weard fault.
Could it be as simple as water ingress on the ABS sensors connections ? WD40 
if the wheel with the dodgy caliper has park brake on.
replace the brake chamber, sometimes the brake chamber fails internally and the air in park brake side of the chamber, which is there when you are driving, bleeds through into the service side of the chamber and puts the brake on slightly,
the same as if you were driving along resting your foot on the brake pedal,
so change the chamber and see if that cures it, was a common problem on that age scania.
hope it helps
i had the same problem on my x reg 420 6x4 about six months ago managed to limp it into scania exeter they checked it over and said they could not find anything wrong with the brakes touch wood it has’nt happened since. i thought it was going to go up the hedge when it happened to me. 
I had a similar problem with an Iveco turned out to be a leaking relay valve, but most common fault is a sticking caliper or brake pads, strip it all down and rebuild