[FarmerJohn]

Hi
I need to change the vacum lines on both my cars (96 passat & a3 jetta)
I've read that I should get 3mm & 4mm silicone hose
Does anyone know how many feet of each you need for either car?
Thanks John

 

[chittychittybangbang]

I've found that 3mm may be too tight. Try to get about 5 feet of 3.5mm. Also get about 15 feet of 4mm, it will go on easily and is probably a better choice for some of the larger ports. So about 35 feet for both cars. This should be enough as long as you don't butcher the lines while cutting them. Those are inner diameter, outer diameter doesn't matter as much as long as it's not huge (and it won't be for these small hoses)

Here is a good source to get it from:

http://www.mcmaster.com/

The only one which isn't on the diagram below is the ecu hose. If you haven't replaced the hose inside the mk3 ecu, it'll go sooner or later and set a CEL (MIL) (check engine light). See http://www.myturbodiesel.com/1000q_how_to/a3b4/ecuhosechip.htm for the replacement procedure.

 

[FarmerJohn]

Thanks
I've got cel on in both cars & some loss of power
That's why I'm doin all the vac lines
Will do the ecu too
What size is that hose?
Thanks John

 

[FarmerJohn]

Just re read the link & see it's 3mm
Thanks John

 

[chittychittybangbang]

Some are 3mm, most are 4mm.

The ECU hose is 5mm, I will fix the link's info to show the correct diameter. A 4mm silicone hose will stretch out and work perfectly. 3mm hose tends to have thicker sidewalls and won't stretch out as much.

 

[diesel guy]

The 3 mm silicone will stretch if it's too tight, so if you can't find 3.5mm I wouldn't worry about it. The 3mm isn't as stretchy and feels harder but I've found it best for connecting to the thin hard white vinyl tubing that is used in some places instead of the rubber tubing.

Welcome to the forum! If you look through the FAQ links that begin with "1000q", you can find a lot more info. It's organized by mk3, mk4, general diesel knowledge, etc.