Vacuum cooling system filling device

Hi.


I was planning to do a major service on my Touran (BMN 170hp) lately, including cleaning the intake manifold and throttle body. I noticed that, according to the VAG repair manual, the cooling system for this engine can only be filled with a special cooling system filling device. The generic version from eBay costs around 80€ and seems to create a vacuum in the system, which should eliminate the need for bleeding.


Do you absolutely need it for that engine? There's no mention of it for the 140 hp TDIs...


The other thing is whether changing the timing belt/removing the camshaft pulley requires any special keys or tools... I already have the alignment pins and the crankshaft stop. I still need to order some longer bolts for the PDE's mounting bracket... Are the bolts on the KW pulley really Torx?


Thank you in advance for any helpful suggestions.

Hmm, I haven't heard of that before, but I can imagine that there are components in the cooling system that are difficult or impossible to bleed without special tools or assistance. This could include things like heat exchangers, oil-water coolers, and EGR coolers, etc. Perhaps it's because there's a higher point in this cooling system that's inaccessible, even higher than the reservoir.

Quote:

Hmm, I haven't heard of that before, but I can imagine that there are components in the cooling system that are difficult or impossible to bleed without special tools or assistance.

I am using a filling machine from Valeo (Valeo Fast Fill).

Works 100%. Under the most unfavorable circumstances, but rather rarely, it may be necessary to add some coolant after the engine has warmed up.

Very suitable for refilling (when the container is empty).

Not suitable for topping up only, as the vacuum suction will also remove any remaining coolant.

Advantage: A functional cooling circuit is immediately established after the engine starts.

Hi.

So, you basically just suck the liquid in with it... which means you could probably just build one yourself using a Venturi nozzle.


The question is, why is this extra part needed for this engine? The installation situation shouldn't be drastically different from, say, a Golf... and it's almost impossible that something is mounted higher than the expansion tank. Well, I'll see. First, I'll completely drain the system, then I'll apply vacuum, and hopefully, I'll be able to see if there was still air trapped somewhere in the system.

Tomorrow, we'll be installing a new differential pressure sensor and new software.


Thank you.

Hi,
Air venting is only possible where air is present, i.e., at the highest point of a fluid circulation system. With the exception of a line that is open at the other end. In that case, air bubbles can be drawn out of a line if the viscosity and pipe diameter are appropriate (see...). Brake fluid).
However, it is generally not possible to vent through a liquid.
It is also not possible to empty a container with a single-sided opening and no open end, unless the vacuum on the suction side is so high that the liquid evaporates.
Same for unidirectional filling of a loop. If it's not starting from the highest point, then this will only work as long as the pressure inside the air bubble in the upper part is equal to the filling pressure.
hg
Herbert.

Quote:

so, it only sucks the liquid in... which means you could also simply build it yourself using a Venturi nozzle...

Of course not. The Venturi nozzle removes all air from the cooling system, theoretically down to absolute 0. Only then does the valve to the hose open, and a pressure equalization occurs, allowing the coolant to flow into the air-free space (the cooling system). Therefore, it is not suitable for refilling.

If there are any vent valves still installed on the vehicle, they should still be used after filling the system.