Paul H. (near Annapolis, MD)

I just got done installing the boost gauge kit from AWE. Not bad! The gauge pod doesn't perfectly fit my A-pillar, but with some minor modifications I should be able to get it to fit perfectly.

HOWEVER, the instructions say that on the 97-99.5 models you can tap into a green fitting on the hard brake booster line near the firewall. The only green fitting I could find is a light green semi-cone-shaped nipple attached to one of those disc-shaped plastic vacuum line diaphragm thingys (are these one-way valves?). The nipple is on the manifold side of the "disc" so I thought this would be ok, but all I ever see on the gauge is vacuum. Even when the engine is shut off. Then if I pump the brake pedal the vacuum drops off a little with each operation of the pedal, until it reaches zero.

This tells me I have tapped in on the wrong side of a one-way valve. Unfortunately it is the weekend and I cannot get ahold of anyone at AWE. Once I can talk to them I will update this post, but until then I would suggest that anyone installing one of these kits on a 97-99.5 A4 should IGNORE the reference to a green fitting and follow the instructions for the 99.5+ models and tap into the cloth vacuum line on the front of the intake manifold.

Paul<ul><li><a href="https://forums.audiworld.com/a4/msgs/507395.phtml">Link to thread in A4 forum</a></li></ul>

Paul H. (near Annapolis, MD)

Well, unfortunately when I first hooked up this gauge and discovered that I had the wrong tap it was sunset. So I had decided to wait until tomorrow when I had more light to try the other vacuum line.

So what is it with this mod bug thing anyway??? Here I am, sitting at home, thinking about drinking a Yuengling (drinking one now), and finishing up some things I had started ealier. When suddenly I realized I could no longer wait until tomorrow. I just HAD to have another crack at getting that gauge working! But there was another hitch: I was going to be short 2 small plastic zip ties.

So I decided to take advantage of the fact that my local Home Depot is open 24 hours, and has a well-lighted parking lot.....

I had definitely had found the wrong place to tap in. I plugged the tap by the brake booster, and tapped into the cloth hose on the front of the intake manifold. Well the gauge certainly works great there! Very responsive..smooth..doesn't seem to be lagging at all (which a kink in the tubing might cause).

Went smoothly right up from vacuum into boost, right up to 16 PSI where it held steady. I think I saw it peak at 18 PSI once, very briefly. So far I don't seem to have a diverter valve problem (it is still the original valve).

So either the instructions are wrong, or there is more than one green plug on the brake booster line up near the firewall. In either case, if you install one of these you are probably better off just tapping into the cloth covered vacuum line at the front of the intake manifold.

Aside from that one glitch, it was quite an easy install. The instructions are otherwise very accurate and easy to follow. If you take your time it should take you no more than an hour or so.

Paul

Leszek

My green plug was facing the firewall, I had no problem with that tap.

Jeff_DML

Except my car isnt make full boost. Might be gauge but probably my car, diverter valve I think.

Jeff

Paul H. (near Annapolis, MD)

..I definitely did.

I mean, I did look and I didn't see any other green plugs on the hard vacuum line to the brake booster [at the far end of the intake manifold, near the firewall]. Also, my brake booster hard vacuum line looks a little different from the AWE diagram. Looks like there is more tubing of varying diameter formed in a U shape before the green plug.

Since the green plug has always worked for them, Todd said they do not consider the instructions to be in error and they are not making any changes.

His wording made it seem like the decision was final (he was responding to an e-mail I had sent him when I first had the problem). This bothered me a little bit, because as someone else pointed out we now know of at least one car where the green plug didn't work. Sure, it is possible that I simply had the wrong plug. But if that is the case, as this person also pointed out, then it is possible for someone else to make the same mistake. I dunno, I may e-mail Todd about that, but he didn't seem like he really wanted to discuss it.

Paul