First oil leak..

Discussion in 'Touring Models' started by Mavagrand, Oct 22, 2014.

  1. Mavagrand

    Mavagrand Senior Member

    ..confirmed. Bike has 36k and is a 2008 FLHTC, stock except for stage 1. Noticed a small stain at church sunday morning. Got home, checked where I keep her stored, sure enough, same type stain. Climbed underneath her and I could see a drop of oil hanging off the head of a bolt. It is one of the two bolts at the very bottom of the casing, appears to hold the two bottom halves together. The leak doesn't appear to be coming from the gasket but rather weeping from the bolt. I cleaned it, parked her and checked again today, drop of oil in the same place, on the head of the bolt.

    The bolt sits in a channel and I'm thinking there is some kind of seal in that channel. the bolt is the one in the front, toward the front tire. Don't have a warranty and don't wanna pay an indy to fix if this is simple.

    Is there an "O" ring or gasket that I can check?
  2. atm33

    atm33 Active Member

    The plugs do use o-rings. Also, check out the current thread that was posted on thread sealant by Permatex (I don't have the link, but just look at the recent threads and it's titled something like "another thread sealant". I used it on my car and it stopped a long-time leak. It should work even better on Harleys (tapered pipe thread on the plugs).
  3. Jack Klarich

    Jack Klarich Expert Member

    The crank cases are a machined surface, H D uses a sealer between the halves when assembling, there are 2 alignment dowel rods also, I have never seen o rings on the case bolts, best advice I could give is clean the case good and apply a bead of clear RTV sealer on the case where the seam is
  4. tourbox

    tourbox Senior Member

    Jack is correct on the case halves. No gasket, just a sealant like Yama-Bond. It is not silicon. There are 9 bolts for the case, 5/16x18x3". You may want to try and tighten it. I think the torque is only around 25-35 ft. lbs. Jacks suggestion of sealing from the outside may work for a while. Just make sure the area is good & clean and use a High Temp sealer.
  5. dolt

    dolt Senior Member Contributor

    A picture would help. In my experience, case leaks are rare; not out of the question but one hardly ever hears of a case leaking. I have split a few and put them back together with no leaks and if I can do it I am pretty sure the factory process is better than my shade tree capability. Cases can be cracked from rocks and other road debris but those events are also rare and when the occur, the rider usually notices.

    Also, it has been my experience that quite often where the leak drips from is very often not the original source. I am not doubting your ability to verify that the leak is coming from the case bolt but just suggesting that you take a really close look for an oil trail from somewhere else that is more likely to be the source of the leak. It is dripping from the lowest point where gravity takes over but that may not be the source of the leak. Take the bike to the car wash and clean the cases and cylinders real good, then try to find the origin of the leak again.

    If indeed it is the case bolt, you have no options but to try and tighten. Jack's suggestion of sealant may stop the leak for a while but is a temporary solution.:hii
  6. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    On my re-manufactured EVO motor I developed the same type of drip from the rear bolt on the bottom of the motor. I cleaned the area and used high temp silicone, which I squeezed into the seam with my finger and then tightened the bolt and made sure the bolts on either side were tight too. That was about 9,000 miles ago and so far so good.
  7. Mavagrand

    Mavagrand Senior Member

    Thanx, Don. I'll give this a try.