Hey guys,

Does anyone have a vacuum hose diagram for the 99.5 2.8L 30V? I believe it's the AHA engine, if I'm not mistaken.

I changed my plugs and plug wires yesterday and noticed that most/all of the vacuum hoses are in rough shape.

I tried searching the B5 forum and did a google search, but came up empty.

 

If your doing a full hose replacement, just go hose by hose. Yes it sucks, but you will be 100% sure it is correct. As far as I know, on the 1.8T there is a mini diagram under the hood near the back, may want to look there. Your dealers parts department can always print one if you need. I literally have part layouts/diagrams for every part of my car. If there isnt ine near you, im going up there later, and ill print one and scan it

 

I looked in the Bentley PDF collection that is/was linked on this board somewhere and I don't see a vacuum system section for your engine. I only see it for the 1.8T. But is there not a sticker on your hood or on the radiator support?

 

To be honest there may be, but I haven't seen it yet. I'll have to take a good look this weekend.

Are there any particular "gotcha's" to be alert to when changing vacuum hoses?

 

While you're doing it, take your "suction pump" and clean it out with carb or brake cleaner. You may need to buy some new fittings if any of them disintegrate when you touch them.

I recommend silicone hose (I got mine from Hose Techniques but there are several companies offering it) and you can either use zip ties (get them tight though) or fuel system clamps. Don't use regular worm gear clamps because they will cut into the silicone. The fuel ones are similar but have no cutting surface on the inside.

 

Is the suction pump an inline piece of hardware in the vacuum system? Never heard of that before.

 

This thing: http://www.ecstuning.com/Audi-B5_A4-...uum/ES1891983/

It's under/behind the intake manifold on the 1.8T, dunno about the 2.8.

 

Thanks!

 

Well, the suction pump got replaced along with the check valve when I did the cc breather system replacement this past weekend.

I also bought a vacuum line kit from Blauparts, but the small diameter hose turned out to be 3.2mm, and was too small to use.

Is the correct size 3.5mm for the smaller vacuum hoses?

 

3.5mm is what I used to replace my vacuum hose and it fit nicely.