Check Valve for Radiator - Diesel Heater Part

Hello.

I have a Volkswagen Lupo 3L and I want to connect the auxiliary heater to the primary water circuit. Where can I find non-fuel and oil-resistant check valves? Are there any available from the VAG parts catalog?

Regards,

Paul.

Quote:

What about the VAG shelf?

There were some for the T2 or T3 models.

On the other hand, they are available almost everywhere. Just do a Google search for "diesel check valve". You will definitely find something that suits your needs there.

Hi!

Yes, there are some items available from the Volkswagen section.
As mentioned before, regarding the T2/T3 models.
but from models with gasoline engines.

The part number is 070 129 530.
Hose diameter: 6 mm.

"This also works with diesel fuel; I've often used these check valves as a temporary fix in the fuel lines when the ESPs (Electronic Stability Programs) have failed."
It lasts. Even for years.

Okay, here's the translation:

'Thank you. And another question. Should a second T-fitting be installed after the first one and before the pump? I don't know if the dosing pump can draw air from the tank through the return line. I'm not very familiar with the setup of the PD system.'

Regards,

Paul.

Hi Paul!

Please don't do that... But do it properly!
Besides the risk of fire, etc., you will find here enough justification and at the same time instructions on how to improve things .
/viewtopic.php?t=19861#159625

Best regards from Munich!

Quote:

Should a second tee be installed after the first tee and before the pump?

Are you suggesting installing a second check valve between the tee fitting and the tandem pump (engine) to prevent the auxiliary heater from drawing air into the return line from the tank via the tandem pump?

Actually, tandem pumps usually have check valves installed. I would test that first before you install a restriction (valve) in the supply line.

Quote:

For PD engines, it is ALWAYS necessary to install a tank pickup with icon_exclaim.gif. The main reason for this is that the fuel in the lines becomes hot, and these temperatures can damage both the auxiliary heating fuel lines and the metering pump.

Edit1
@DB

Explain to me how the temperature difference between the supply line (to the tandem pump) and the separate tank pickup is justified.

Sure, here is the translation of the text from German to English:

"Edit2"
Of course, you shouldn't mount the dosing pump directly on the tee fitting; there should be a length of tubing between them to prevent overheating.
It doesn't matter whether you draw the diesel fuel from the tank from the left or the right; it makes no difference to the diesel itself.

Hello everyone!

Tapping into the fuel supply or return line for the common rail system (PD) to power a auxiliary heater is absolutely forbidden and always has been.
...please read the linked thread and/or refer to the installation instructions from the auxiliary heater manufacturers.

@OpaAutoschrauBär: The fuel pump nozzle attaches TO the pressure relief valve.

Best regards from Munich!

Quote:

@OpaAutoschrauBär: The fuel pump sucks in air NEXT to the reservoir.

So what. The soup is still the same temperature.

The thing is, when manufacturers handle the fuel extraction separately, it's safer because you don't know which workshop might be tampering with the vehicles.
Furthermore, you save on check valves, costs, and the hotline for complaints.

Hello!

"I used a T-piece to tap into the fuel line of my Polo AMF for over 200,000 km. Without any check valves. The heating worked perfectly and the engine ran well too. HOWEVER: Unlike many other AMFs, the Polo AMF does NOT have a pre-lift pump in the tank. If a pre-lift pump is present, this setup would likely not work."

Best regards,