DAF XF 105.460 2008 - Coolant reservoir pressure. (fluid out)

Hello, I have 4 dafas, the normal thing is that when the engine heats up the pressure only that in one dafa I have the impression that the pressure is a little too high because the fluid came out practically from every connection of pipes with the tank (the pipes were sweating), otherwise they went down I recently both dafes at the same time after 9 hours of stopping in this car that nothing happens and there is no loss of fluid there was no pressure at all unscrewing the plug and in the second after 9 hours the pressure was still quite high. Test done for the exhaust gas content in the liquid, the vent plugs replaced, the water pump is 4 months old, the tank is permeable to air. I have no idea what could be more .... On org vent plug there are parameters from 06-1.5 bar (then the plug releases air from the system) Does the system have to be pressure and how to do it so that no pressure builds up?

The gasket under the head in dafa withstands about 700-800 thousand. kilometers and probably there will be a reason here.

The gasket under the head is probably but the compressor can still mix something if it is with a water jacket. The CO test should clarify.

The compressors I did not take into account, although I should have. You are right, can check this element first. I have just dafa with a buried engine, tomorrow I will look at how the compressor is cooled.

The compressor is liquid cooled.

Is it normal only if the head or the entire cylinder, or if the head is a blow? Two outputs, or disassemble the compressor and see either:
on a cold unscrew the cap from the tank to release pressure, unscrew the air outlet tube from the compressor so that the compressor does not pressurize (do not compress), screw the cap on the tank, heat the engine and wait until tomorrow to check if there is pressure in the tank.

the basic thing is whether it overheats or not. If not - then the compressor probability is high. I exchanged a pair in XF105 in my life for that reason.

Everyone who has Dafs from 2010-13 and gathers compression, pressure in the expansion tank, there is no uncle in the village so that the reason for this was not a dropped or cracked sleeve due to cavitation-falling out of iron particles within the cylinder seats under the sleeve flange . This is a disadvantage of these blocks. In older models, the sleeve may be dropped due to operation, and only milling of sockets for oversize sleeves brings effect.
Guest from Bielsko Biała comes, milling and after the case!

it's not cavitation buddy. The effect of cavitation is pitting on the surface of cast iron reminiscent of the surface of mars or golf ball. And by the brackets, cavitation is created when the coolant contacts the free surface of the sleeve. In the place where the sleeve has a flange there is a tight contact of the flange surface in the sleeve and the flange surface in the block.
The phenomenon of sleeve fall is caused by so-called relaxation - that is, in the sleeve collar subjected to compressive stress, as a result of temperature cycles, the compressive stress disappears and deforms plastically. The same applies to stresses in the block within the flange.
Current methods used in engine design include FEA simulations and are able to simulate this phenomenon by computer and predict when the phenomenon of internal stress disappears in the material - if it occurs at all.
Read about relaxation in the materials and you will learn, among others why a spring loaded with constant pressure, after a while it gets lower ... And the fact is - this is a disadvantage of these engines. The boring machine is available among DAF's special tools, but it is extremely expensive. I saw it somewhere in 2013 with an electromagnet to immobilize on the block ... You can suspect the sleeves if the car overheats. But if you just build up pressure in the system. cooling and the car does not lose fluid and does not overheat, the compressor will be more likely ...

Unfortunately, there was a problem with Daf in our company in the form of excess fluid. We replaced the compressor seal, expansion tank cap, the problem escalated. Checking the carbon dioxide content of the coolant - negative result. Ultimately, the engine sleeve should have been dropped, and the motor did not heat up. The car had 900,000 raids. I will add that the specific sounds were from the cabin heater. Sitting in the cabin, the engine off, you could hear gurgling.

buddy mechanicDaf, I have a similar problem with dropped bushings. I'm getting on the subject of 'renovation' only the problem is that in Europart and in the car they have not heard of the overcoat sleeves

look for a guest from dafa what is milling daf blocks for oversized bushes on allegro or olx there you will find bearings.

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Hello
In case of pressure in the cooling system, please contact me.
We have a professional boring machine for engine blocks with a knife dedicated to Dafa.
We arrive, measure, and if necessary, mill the damaged socket of the block.
I invite users and workshop owners to cooperate.
Fast, efficient and reliable
Waldek Gdansk
Tel. 603 923 275

is the effect of metal erosion due to cavitation. A phenomenon quite common in the cooling jackets of high power diesel engines. Buy an additive - anti-cavitant for cooling systems.

https://puredieselpower.com/products/dca4-sup...ine-block-cavitation-preventive-1-gallon.html

Here the anti-cavitant will not help, too late! The need for "milling for oversize collets" .

I am just exploring this topic and I came back to materials from my studies. The phenomenon of block surface destruction in this case is fretting.