Vacuum tubing

[lisab4]

What lengths and diameters do I need to replace all my B4/1Z vacuum hoses?
Also, the fuel hoses from the IP to the injectors.

 

[jhax]

5/16 inches and 1/4 inches for the fuel line, I want to say 1/8 inch for vacuum but I could be wrong.

 

[turbodieseldyke]

Search Button is your friend.

 

[moroza]

Search Button gives conflicting answers.

I used about 3.5 meters of 3mm, and 1 meter of 5mm. This was enough for all vacuum lines including the one inside the ECU, but I don't think it includes the recirculation valve (for the cabin air, not EGR). I used silicone which is fairly stretchy, so my diameters may be slightly off.

Be very careful removing the blue hose to the wastegate actuator. It's hard to reach, even harder to see, and I broke the nipple off the actuator, then spent a while removing and repairing it.

 

[lisab4]

Thanks! I assume the 5mm is for the fuel lines?
All hoses are gone (total restoration & rebuild engine. Will be fun figuring out what connects where

 

[JETaah]

5mm is for the EGR valve to N18 connection and vents to the air box.
I don't think that the VW braided vacuum hoses are diesel fuel compatible.
They have a special one denoted with a yellowish stripe on the braiding for the injector return lines...at least the ones that I have seen.

 

[pdq import repair]

VW braided vacuum line will not stand up to diesel fuel as mentioned above. You need the special yellow stripe stuff for sure there.

5 and 7mm fuel lines come in smooth skin too if needed. Might be wise to talk to a VW parts guy or a smart independent locally.

 

[ToddA1]

I bought a bunch of the smaller stuff and don't remember seeing a yellow stripe.

http://www.autohausaz.com/search/pr...=22@Fuel & Air System&gid=6352@Fuel Hose/Line

The return lines Kerma sent me, with injectors, don't have the stripe, either.

-Todd

 

[JETaah]

VW's part number for return lines is 059130329

http://www.dbwllc.net/product/059-130-329-braided-fuel-line-rmebiodiesel-rated/
Maybe the yellow stripe is meant to be compatible with biodiesel as well as D2...Don't know. I don't see the stripe in the pictures, though.

The return lines that Kerma/DBW has sent me with the injector rebuilds in the last few years has always had the yellow stripe. It is faint but, it is there.

 

[lisab4]

Questions:
* The white plastic vacuum line on the right of the engine goes to? Heater core?
* The vacuum line from the ECU goes to? Intake manifold?
* Black plastic line/rubber line goes from N18 to vacuum pump?

 

[turbodieseldyke]

http://pics.tdiclub.com/data/516/medium/A3_98_Jetta_TDI_Pressure_Vacuum_Diagram.jpg

 

[lisab4]

This is how I see it

 

[turbodieseldyke]

Ecu goes to Intercooler pipe, not intake.

"Heater core" is actually the Recirc door, but in the same general area.

 

[lisab4]

I see no nipple on the intercooler piping?
And where does the intake nipple go to then?

 

[lisab4]

This is my intake. The European one has the EGR valve bolted to it, not one part like the US.

 

[JETaah]

You are right...intake manifold in your case.
So much smarter to make the EGR a separate part.

 

[lisab4]

Thanks!
EGR is easy to block also. Removed one metal pipe between the valve and the exhaust manifold, blanking plates on both ends, and voila, done! EGR still operates, so no codes

 

[lisab4]

I've adjusted my diagram to reflect the remarks.
One more question, if the intercooler pipe/intake goes to the ECU, doesn't it clog the ECU sensor with dirt/oil?

 

[JETaah]

It can transfer intake oil if there is a leak in the ECU hose as there quite often is. If there isn't then it is a lesser concern because it just compresses a column of boosted air in the hose....no significant flow.
The turbo to N75 to wastegate hoses do fill with intake oil and that becomes more of a clogging issue. Gravity helps the oil residue make it's way to the wastegate actuator being that it is the lowest component in the control system.

 

[vanbcguy]

I've adjusted my diagram to reflect the remarks.
One more question, if the intercooler pipe/intake goes to the ECU, doesn't it clog the ECU sensor with dirt/oil?

Unless there's a leak nothing actually travels through the hose. There may be a tiny bit of ingress where the hose meets the intake but oil etc shouldn't find its way more than an inch up the tube, if that. The same column of air stays in there getting squished with pressure then springing back.

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[Windex]

If you are concerned about oil migration ( I had quite a bit of accumulated oil in my WG actuator) then install a "drip leg" to catch the oil.

Common in natural gas piping to install a redundant leg to catch water and prevent it from entering into sensitive equipment.

 

[lisab4]

Thanks guys!

 

[vanbcguy]

FWIW the wastegate actuator has a fair bit of volume to fill, hence the oil migrating through the pressure line. The MAP sensor on the other hand has virtually none.

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