Oil tank vent line

Discussion in 'Softail Models' started by gator508, Nov 4, 2013.

  1. gator508

    gator508 Senior Member

    Hi everyone,

    I posted under Gatlinburg Vacation that I had a problem with the oil filler cap coming loose while riding in the mountains on my softail. Thought the problem may have been a contraction issue with changing temps so quickly. Well, yesterday it happened again while on a ride with my wife. Anyone else ever have this issue.

    Questions: Does this sound like the vent line may be clogged and needs cleaning. Searched for answers here but to no avail.

    Could if be the rubber seals on the cap are worn enough it just blows out when riding.

    Local dealer is not open yet so I'm looking for help to fix myself.

    All input will be appreciated, Thanks!
  2. Breeze3at

    Breeze3at Well-Known Member

    Russ; Is there any possibility that your oil tank is over full? Even though there's a vent line, there needs to be sufficient head space in there for expansion.
  3. gator508

    gator508 Senior Member

    Hey Pete,

    Thanks for getting back. No, I have triple checked that one, it was my first thought.

    Went to HD today and discussed this issue. Their suggestions were:

    Check the bolts from the head to the breather tubes in air filter, if plugged can cause pressure. Check the tubes also. Not a very likely cause. I checked them they are fine.

    Change the air filter element. Somewhat of a likely cause. I looked at the last time I changed it, was right before Salt Springs this year ~ 6K on it, so it's past due. Bought and installed new element. Did notice the old element had some carbonization going on, so maybe that is the cause, we shall see.

    Checked some of the softails at the dealer, the oil caps were quite a bit tighter fit than on my bike, so it maybe worn out and not sealing well, could be the main cause. The good news it's covered under the extended warranty, going to put some miles on her and see what happens. I'll post results when the problem is resolved.

    thanks Pete.:D
  4. cortezc

    cortezc Member

    surprised that HD not more concerned....i have experienced similar two different times and it was not good news...my experience it has been internal problem so at least make sure where you are with it before making it a lot worse...
    good luck and hope you dont have to go inside...
  5. gator508

    gator508 Senior Member


    Well I hope its nothing internal, but it should be covered if it is.
  6. Billbo

    Billbo Junior Member


    Hello Gator, while you may not have the same problem, I have a 2001 Heritage and my oil filler cap (one with the temp on it) got to where it would blow out when I started the bike. My bike seems to me to "HIT" real hard when I start it. Anyway, the cap would slide in and out pretty easy. I bought a new one and my goodness - I can hardly PULL it out to check the oil -- was definitely worn out rubber seals. I dont think hi-test nitro-glycerin could blow the new cap out. :D:D Hope this might help a little.

  7. geezer

    geezer Senior Member Contributor

    Gator, this happened on my Heritage as well. The rubber on the dipstick was worn or had shrunk. I cut a piece of garden hose the length of the factory rubber, slipped it over the dipstick and pushed it into the dipstick rubber. The garden hose expanded the factory rubber enough so it's tight going into the tank again. This farmer fix has worked for 2 years now and the dipstick has never come out when I'm riding. This might be a cheap fix for you as well.
    BUBBIE and DannyDeluxe like this.
  8. gator508

    gator508 Senior Member


    Billbo and geezer,

    Thanks for the replies. Fixing to( that's a southern expression:D) go riding for awhile to see if the a/c element has any effect or if it blows out again. If so I will happy myself down to the dealer and get a new cap, will probably do that anyway since it has seen previous problems. The farmers fix sounds like a winner, the cap is covered under my extended warranty. Cheers Ya'll:D
  9. FerrousBueller

    FerrousBueller Junior Member

    You have a FXSTC also? I have to commend you on your excellent choice! You are obviously a rider who knows the best!

    I've had a similar problem with my '09 Softail. I bought the analog temperature dipstick with my bike and have had the same problem. I "clocked" it so that when the needle pointed forward, it was at 200° mark. Then I knew it was time to pay more attention to it. I've had it like that for a couple of years. In the last year or so I got into the habit of reaching down and checking it after starting. Turning the cap 45° seemed to help for a while.
    After servicing the bike the last time I lit the bike without being on it... the cap shot out of the tank and into the dirt driveway. I was on my way to my place of employment (work is such a nasty word here on the forum) that I just grabbed the original cap and shoved it in.
    I like the garden hose remedy, however, I've seen somewhere on this forum about the use of a rubber restoring product that will make the original seal more pliable and grip the filler neck more tightly.

    I hope this may help.

  10. gator508

    gator508 Senior Member


    Hi Ferrous,

    Yes, I do like my tail, she's been a good ride.

    As stated, I did happy down to the dealer a got a new cap, I'll put it in this morning, and if there is no rain I'll take her out for a spin, hope the problem is solved. Thanks for getting back!