Gas tank venting

[SoftailDave]

Last year I noticed that when I leave my '97 Heritage Softail Classic out in the sun pressure builds up in my gas tank from the gas expanding from the heat and there was a small puddle of gas under the bike. When I release the right gas cap you can hear the air pressure releasing. So now when I park the bike I have to unscrew the right tank cap so pressure doesn't build up. On the right gas tank there is a hose located under the ignition panel that I believe is supposed to release this pressure. I disconnected it and tried to blow through it. You could blow throught it  but it wasn't easy. It seems to have a one way valve on it as it is possible to blow through it but you can't suck air throught it. I did a quick check of the line and I don't see that it is pinched anywhere. Do these valves fail? Is there anywhere else that should be vented to release the pressure ie. gas cap?
Thanks!
Dave

[JohnFlorida]

Right hand cap should be vented

[SoftailDave]

It seems like my right hand cap is vented but only one way i.e., air can enter the tank so there won't be negative pressure (vacuum) but won't let air out when tank has positive pressure from expansion of the gas. Maybe my right hand cap is screwed??

[JBarrettB]

I think there was a bulletin about Softail tank vents around that time. Trace the vent down to the swingarm. Pull the line from the fitting in the swingarm and clear the fitting with a paper clip...could be more to it, cant recall all the details.

JB

[SoftailDave]

Thanks JB, I will trace that vent tube to the frame and have a look at that fitting. If that doesn't work I may replace my existing caps with a pair of those flush mount caps.

[JBarrettB]

Your caps are good. Air in only on the right cap and the left is not vented. The overflow line/vent line is for over filling when gassing up and venting pressure out.

JB

[FSG]

I think there was a bulletin about Softail tank vents around that time. Trace the vent down to the swingarm. Pull the line from the fitting in the swingarm and clear the fitting with a paper clip...could be more to it, cant recall all the details.

That would be M-1085 , Fuel Tank Vent Line Connector found in the SECTION.  While it pertains to models built between Apr and June '99, it does sound like the Ventline Connection or Vapour Valve on your '97 could do with some paper clip attention.

[SoftailDave]

I am installing a new cam, lifters and pushrods plus a new clutch cable this weekend so while I have the bike up on the lift I will look for this ventline connector and try and clear it out.
This forum is just an awesome source of information, thanks everyone!
Dave