Diverter Valve Replacement - Some tips from my experience

[Hijack]

Since I seem to be following the "paint by numbers" format for standard upgrades to my TT, I'm now on the Diverter Valve and F Hose replacement part of my journey. And boy, how fun this is (sarcasm intended). I figured I'd give the "average joe" version of the DIY process for these to give those of you looking to do this replacement and idea of what you're going to run into.

First, as should be common sense with every physical job, don’t start without the right tools. However, as most of us can attest, very few learn this before they already start a DIY project. For Diverter Valve replacement, do not even try this job without a proper set of “cable operated hose clamp pliers”. They look like this:

You can buy them at Sears for around $40. Your knuckles and your sanity will thank you later. The ability to lock lets you set them down and use both hands to work on removing and installing the DVs (which, brother, you’re gonna need!).

To begin the process of actually removing the OEM DVs and install aftermarkets, many people use the DIY instructions published by AWE. These are good instructions, but one part may be incorrect. In those instructions, they infer that there are worm-drive clamps on the bottom of the DVs. That is incorrect, at least on my car. All the hose clamps were constant tension, spring style as in the picture above. There are 5 hose clamps to worry about. There are three on the F hose that leads from the DVs to metal intercooler pipe and there is one on the bottom of each DV where they attach to the Y hose. The two hardest to deal with are the one on the F hose towards the front of the car and the one at the bottom of that corresponding DV. Here’s why; on my car at least, the compression tabs on the clamps were facing the front of the car. You cannot get to them with a regular set of pliers. You cannot spin these clamps without compressing them either. So unless you have the pliers I referenced above, or a set of C-clamp pliers, you’re SOL. These are C-Clamp pliers:

Once you have the proper tools, following the AWE DIY instructions to the point of removing both DVs and the old F hose is relatively straightforward. However, getting the new ones in is a PITA.

If you are going to use a new, silicon F hose, the job does become a bit harder for one reason. The OEM hose is rubber and allows you to insert the ports of the DV much easier since it stretches (which is one of the reasons it can leak). The aftermarket F hoses are much thicker and much less malleable, so inserting the DV ports into the F hose is more difficult; so much so that you need to be able to twist the DV back and forth to wiggle them in. As such, you will need to attach the DVs to the F hose first, before you put them back into the lower rubber Y hose.

The first DV (towards front of car) is much easier to install. Attach it to the F-Hose and clamp it down. Then install it into the lower Y hose. You can wiggle the DV back and forth to help seat it into the Y hose. The second DV is a PITA! NOTE: Aftermarket DVs like Agency Power’s models are much larger than the OEM parts. They will fit snuggly up underneath the engine compartment. As such, you need to reattach the vacuum hose to the top of the front DV prior to starting to work the the rear DV. You won’t be able to move them around enough after both are installed to get to the top hose connection on the front one. The nice thing is, at least the connection is a 90 rotating fitting so you can get at it easier than the old vertical OEM version.

After this is done, you can start work with the second DV, which is truly a PITA! Here’s the issue, since you need to clamp it into the new F hose first, you don’t have a lot of room to work with as you’re trying to push it down into the rubber Y hose. Since it’s already clamped into the F Hose, you cannot turn it back and forth to help seat it and since the Y hose is RUBBER, it keeps bending away from you as you push down into it. To combat this, I simply fished a wire under the Y hose and held both ends in one hand like a leash, pulling the Y hose up as I pushed the DV port down into the hole. If you really have problems with it, you can lubricate the bottom DV port to slide into the rubber. It won’t come lose due to the lubrication once you’ve taken the clamp pliers off the hose clamp, so don’t worry. The orientation and restraint of both the F hose on one side, and the Y hose below won’t let the DV move at all anyhow.

Once the new DVs are in, reconnecting everything else is super easy. Good luck!

[daytrip00]

I read this post before attempting my own DV install this weekend. This was a lifesaver and I can't thank you enough.

Unfortunately it didn't include disconnecting the airbox to look for a hose clamp that was dropped into the engine bay. That adds another hour to the install process :P

Thanks so much... the hose clamp puller was a life-saving suggestion.