W123 Fuel tank vent plugged and collapsed my fuel tank.

Check your tank vents, or you might end up with a collapsed fuel tank like I did. If you get a whoosh of air sucking sound when you remove your fuel filler cap after a long drive, you need to check this now!
This can even cause reduced power as the engine will starve for fuel after enough vacuum builds up in the tank.
In this video we cover not only checking the tank vent for proper operation but also repairing my collapsed tank, and several thoughts on how you could re-inflate your fuel tank that has become dented in.
0:00 Intro
2:12 Wet dry vac
4:34 Air compressor
5:47 Much improved
6:14 Why it collapsed
8:15 The valve
8:56 Cleaning/Breaking valve
9:56 Reinstall valve
10:48 Good to check again
11:42 The shake hands with danger method
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[@ebutuoyebutouy]

Primary fuel pump must be in great shape. Thanks for sharing.

[@trythistv]

Pulled an impressive vacuum for sure! Didn't seem like fixing the tank vent changed how the car runs at all though, I was curious what effect it would have.

[@ebutuoyebutouy]

@@trythistv Fuel starvation. Low power and quitting engine just like blocked fuel filters. Your primary fuel pump is still getting enough fuel to the IPump. Awesome.

[@danchekan1055]

Hello, Really learning a bunch for keeping my W123 in good shape on your channel. I discovered that my check valve is missing. Wondering why it is even necessary as fuel never leaks out and can’t see that any real debris could be drawn in. Maybe just a filter if on dusty roads

[@trythistv]

Glad my videos are helping you out! I do suspect that the check valve is made purely to be a filter or at least a deterrent to keep bees or other insects from making a nest in the metal tube.

[@squirehaggard4749]

Great video, as always. Perhaps you could ziptie some window screen material around the end of the vent. Just a thought.

[@trythistv]

Excellent suggestion. Might keep the mud daubers out and prevent this happening again!

[@vintage76vipergreenBeetle]

Nice info.

[@trythistv]

Really shocked me when I pulled that panel off! Something everyone should be aware of and check to make sure that vent is not clogged up!

[@brettgraybill2435]

@trythistv did you ever replace the check valve? If so where did you find one? Thanks for the great information

[@trythistv]

I completely forgot to. I've been driving all over with the one I blew the guts out of in the video. it has been a-ok, but I should get something in there before those dirt daubers make another nest further up the hose!

[@GhostofLu]

Is this in same in w210? I have buy that valve but i dont know where i install😂😂😂😂

[@trythistv]

I'm not certain, but I suspect it would be very similar, I'm fairly sure the W124 (E300D) I used to have had the same style valve underneath somewhere, but I have not owned a W210 to know for sure.