I apologize in advance for the length of this, but technical problems require technical explanations.

Some time ago I installed a VDO boost gauge and pod in my 1998 V70 T-5M. I ran the vacuum tubing from the vacuum tree up to the A-Pillar along with the electrical wiring for the gauge lamp. I installed the pod, then connected the wiring and tube to the gauge and pushed the gauge into the pod. The fit was snug enough that I chose not to use the included bracket. I felt that this would make a later removal much easier, if I had to replace the gauge lamp or remove the pod in order to remove the upper facia. My prescience was rewarded, when my AC evaporator needed to be replaced, which required a field stripping of the entire front of the cockpit by my indie. But, that is another story.

Following that replacement and the reinstallation of the upper facia, pod and gauge, it seemed that the boost indication was less responsive than prior to the removal. When I pulled the gauge from the pod, I could see that the plastic vacuum tube had crimped where it entered the brass fitting on the back of the gauge. From the location and orientation of the crimp, it appeared that the tube had been jammed against the curved portion of the back wall of the pod. When I pulled the gauge out of the pod about an inch, boost readings were much more responsive in speed and amplitude. When I again seated the gauge, the readings again became less responsive. It seemed clear that seating the gauge was crimping the vacuum line and affecting the readings … not unlike crimping a garden hose.

That caused me to find my trusty tape measure to check distances. Here is what I found:
• The vacuum fitting is located at the 6 o’clock position on the back of the gauge and near the outside edge.
• The distance from the faceplate of the gauge to the tip of the brass fitting is about 3 inches.
• The distance from the face of the pod to the curving pod back wall at the 6 o’clock position of the brass fitting is also about 3 inches.

I was now sure that there is insufficient space for the stiff plastic vacuum line to make the curve dictated by the shape of the pod back wall at that location. As the gauge is seated, the pod back wall forces the vacuum line to bend and crimp shut.

While VDO manufactures the gauge, I don’t think that they make the pod. When IPD mated the VDO gauge to IPD pod, it seems that they overlooked this potential problem of tubing bend radius and gauge-to-pod clearances.

I now keep the gauge pulled out about an inch in order to get accurate readings, but it is very unsightly. I plan to replace the tubing, but I fear that it will result in the same problem for the same reason.

Has anyone else experienced this problem? Is there a fix? Is IPD reading this?

--
Dave in Virginia; 1998 V70 T5(M): IPD MOTRONIC+ ECU Upgrade, Sport Muffler, IPD Strut Tower Brace; VDO Boost Gauge, IPD Anti-Sway Bars, Rocha ABS Control Unit, Koni FDS Struts and Shocks/// 1988 245 DL Wagon// 1967 MGB Roadster