Scania 114 (2002) Trailer Brake Advance Adjustment: Comparing Pressure & Valve Locations

Hello
The problem concerns Scani 114 2002 on discs, so what kind of trailer would I not attach it to Scania blocks the wheels faster than the trailer. The effect is that on a slippery semi-trailer, the tractor pushes the tractor until the brake pedal is pressed harder, and I do not have to write that it is quite dangerous.
After exploring the topic a bit, I measured the pressure on the rear cylinder of the tractor and the yellow steering cable of the semi-trailer and it came out about 1 bar difference, with another tractor this difference was at the level of 3 bar, hence Scania simply has a wrong advance angle of the trailer brakes.
Can any of the Farum fans tell me where this lead is set?
Is europa on the valve? Because the trailer control cable comes out of it, or is there a control valve somewhere else?

How a mechanical valve is on it and electronics is a sp2 program.

The valve is as mechanical as possible because no electric wires enter it. So it is surely manual adjustment only how?

Enter the chassis number there were two types.

The chassis number is: VLUR4X20009073128
There is a valve, but you do not see a rare adjustment on it, someone advised me to remove the vent and from the bottom supposed to be a relulation screw, the screw was so much that there was no rare reaction when it comes to pressure differences.

In the evening I will send you the data, take it easy no rush these are the brakes!

Precisely because these are the brakes, I want everything to be ok there.
And is it possible that the axle load sensor was the culprit of all this confusion? How is it with this semi-trailer pressure regulator, it is controlled by the pressure from the brake pedal or already from the rear axle modulator, if someone had a diagram, I would ask you to send it because I found something on the net but these are diagrams without pneumatic suspension.

In the appendix what you need if you write something. Read about the principles of the EBS system, you will find out what this "axle load sensor" is for

Helpful and well described. Thanks for sharing !!

Thank you very much for the helpful literature. For me, the cause of all the fuss was probably the axle load sensor.

Hello
I thought that the topic was finished and the fault was removed, but unfortunately, I thought.
After careful measurements and comparison of the results with the results of a functional car (although of a different brand, but the principle of operation and the construction of the ukald are similar) my suspicions fell on the main brake valve.
If I connect a pressure gauge to any cylinder on the tractor:
-when the ignition is turned on, the tractor always brakes strongly from the pressure of the control going to the semi-trailer
- with the ignition off, the advance is approx
-when I turn on the ignition (i.e. the entire ebs system is active) and I have 2bar in the actuators, the control pressure on the semi-trailer is much smaller and as the ignition turns off, the pressure on the actuators drops sharply and is smaller than the one coming out on the semi-trailer (so then the advance is ok )
To my knowledge, there are two braking systems:
- electronic
- ordinary manual
both depend on the level of pressing the brake pedal, but the electronic one additionally regulates the braking force depending on the axle load, i.e. the pressure sensor indicated, but its maximum should be the pressure that is set by pressing the pedal without the electronics on, it should only capture the brake pressure so that when empty The wheels did not lock up immediately after a light touch of the brake pedal.
I suspect in my case manual control and the electronic one has gone, that is, it has a large difference and so I have such a circus with this car.
The question now is as follows:
- can the pedal be adjusted manually or electronically, although I focus on manual adjustment because you have to press it quite hard so that there is any pressure in the actuators with the electronics turned off, of course
-if I have to replace this valve or there is some pressure regulation which is the power supply of the brake valve.
-if my thinking is wrong and the fault has a completely different cause.
If someone knows something, please give me a hint.

I have not done a scani for a long time because it rather rarely breaks down, but something dawns on me that there is a sensor between the pedal and the valve and some adjustment of this sensor

Buddy duck, thank you very much for your interest and answer, but if someone could write where exactly it is and how to adjust this sensor, I would be grateful.

As you already know that all settings are made in the program, what have you done with this adjustment? The brake pedal has these values permanently assigned at the factory as characteristic and they are inserted (or in case of replacement, they must be patched) into the EBS unit memory from the number on the valve. Brake pedal test values 0.3-4.5V / 4.6-0.3V. Brake pedal extreme values 0.3-05V / 4.4-4.6V. Returning to the problem, which gives you flying around the valves, as you have no idea about the sensors in the modulator, where computer diagnostics is indispensable. And where are the error codes? You're wasting your time, man. The real test has two phases: controlling the pressure (measurement to pneumatics) using a computer with a pressure gauge and measuring (on a sensor) the modulator pressure in the same way in a purely pneumatic mode called (incorrectly, in my opinion) emergency. In a word of professionalism, let him diagnose Europe.

I add that:

marcing1988 wrote:

when I turn on the ignition (i.e. the entire ebs system is active) and I have 2bar in the actuators, the control pressure on the semi-trailer is much lower

This is abnormal modulator behavior, because it is not about doing what it wants.

marcing1988 wrote:

And as the ignition turns off, the pressure on the actuators drops sharply

I would say that this is normal due to the loss of air in the modulator, which translates in peasantry "to pressurize too much".
You should not do this, but in case of suspicion you have to measure the air loss on the trailer's supply.
I checked it only in the manual and the maximum permissible drop is (minus) 1.5bar within a maximum of two seconds.
Prerequisite: Packed winds, manual release and pedal fully depressed.

marcing1988 wrote:

I suspect in my case manual control and the electronic one has gone, that is, it has a large difference and so I have such a circus with this car.

As a modulator is replaceable, it has the right to act alogically and finding the cause may be both easy and extremely difficult, or even impossible.