breale01

Found some old threads on this subject (back to 2003) but none seem to hint at whether having the tubing connected is beneficial or not. Mine seem to have been disconnected, but my investigation into why isn't yet complete. Seals seem to be part of the puzzle.

Any insights out there?

boxsey911

The design of the vent hose on its own did not prove to be effective at stopping the lenses misting up. Therefore, the lenses introduced later have a grill around the whole of the lens and don't use a full rubber seal. This allows air to circulate behind the lens to keep it dry. The vent pipes are still attached to the new lenses but I doubt if they do much.

John Boggiano

There are two sides to the condensation problem - first try to stop water/moisture getting in (good external sealing), second make sure any that gets in can easily get out again and that the unit is not completely sealed (which would cause problems as the temperature changes).

Mine certianly did better with the tube attached - it keeps a positive pressure inside the lamp preventing moist ait from being drawn in.

John Boggiano

Note - the later lights with the vents on the edge - the vents don't vent the inside of the lamp itself - they just vent the surround to keep the temperature down. So the air from the tubes doesn't communicate with what appears to be the 'outlet' vent.

breale01

That clarifies most of it, but just to confirm my understanding:

- The tubing provides positive pressure to the internal lamp area.
- The later type of lights have openings to vent the 'box' area which is separate from the lamp area.
- Both old and newer type of lights have an attachment point for the tubing.
- Newer type of lights have a different type of seal to accommodate the vent holes for the 'box' area.
- Opinion varies on whether having the tubing attached actually helps.

Whew, let me know if I got it right!

John Boggiano

He's got it!

John Boggiano

Although...

One thing I found very interesting (in that rather **** sort of way that we all share) is that my original lights (stamped with a manuf. date of something late in '89) were not a matched pair. The right hand one was what you might call the 'early' style, but the left one wasn't. When I pulled off the old seal, what should I find along the top edge, but a strip of vents...

breale01

Interesting....can't wait to take mine off and see what I find! (Can't believe I just said that).

John Boggiano

Even more interestingly, my rear lights' vent hose was also disconnected when I bought my car.

But I think that, rather than for any technical reason, this was related to the fact that there was a crisp packet stuffed down inside the OBD socket and an oily mark on the driver's seat, following the 'thorough pre-purchase service' that the car was given...

breale01

Mine's disconnected high up near the heater thingy. There's just a little elbow coming out with some electrical tape wrapped around the end and no sign of any tubing. I'll try and upload a picture today. (And since yesterday was actually the first anniversary of my purchase, it might be appropriate for me to finally post a picture of the whole car)!

Crisps?...oh right, chips.

John Boggiano

Crisps/chips - you got it!

boxsey911

Same here John (almost). I replaced my left light because it was original (full rubber seal), very pink, very cracked and very wet. The right light had been replaced and had a full seal and was in decent condition. A year later I bought a used lens of the later design to replace it and balance the look only to find that one I took off was also the later design but fitted with a full seal by mistake.

BTW anyone buying used lenses that look good and dry on ebay should be aware that they might mist up within a few days of putting them on the car.

breale01

Just for completeness, here's the picture showing the little elbow with the taped end:

Livefreeandrive

Looks like somebody put th distributer vent outlet in the wrong place............?
See the big detailed picture in the post regarding distributer vent/belt replacement.

breale01

Found it, the Wachuko picture.

I see what you're saying. That elbow in my picture above looks very much like the Distributor Vent Tube elbow in the Wachuko picture.

I know I've got the distributor vent mod....now to figure out if it was installed correctly, and solve the mystery of the 'extra' taped off elbow....

Thanks for pointing this out.