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leaky Stihl fuel cap

Discussion in 'Lawn Mowing' started by Stonewall, Apr 24, 2001.

  1. Stonewall

    Stonewall LawnSite Senior Member
    Messages: 280

    Has anybody had a problem with a leaky Stihl fuel cap? My BR 400 blowers have a tendency to build up pressure and leak fuel out the cap and drip on the concrete, grass, or whatever. I had an old Redmax blower that did the same thing. Does this mean the vent on the cap is clogged?
  2. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    You may just need a new rubber seal. I know this happens all the time, and I keep a bag of them in the kit with us. Also, after a while the caps themselves wear out, I'm always on my guys not to reef them down too tight. If it's a blower though, it IS very possible that that is what it is doing, building up pressure from sitting. It doesn't seem like it would cause gas to come out though, unless it was filled right up to the cap, or it was tilted so gas came over the top of the tank spout.

    [Edited by Runner on 04-24-2001 at 12:52 AM]
  3. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Messages: 3,645

    I had the same problem, replaced fuel cap under warranty....no problems. Dave
  4. Stonewall

    Stonewall LawnSite Senior Member
    Messages: 280

    It doesn't necessarily happen when the tank is full. You know the pressure is built up because when I loosen the top, fuel spews all over the place.
  5. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    It sounds like you may want to look into a vented cap. Just make sure you fing one that fits it properly. Another thing you may want to try, and as I thought about it, I realized I do it without even thinking about it, is loosening the cap slightly and slowly, and allowing the pressure to release, THEN remove the cap. I've even just loosened and retightened them occasionally on hot days. Just habit I guess.

    [Edited by Runner on 04-24-2001 at 01:20 PM]
  6. mdb landscaping

    mdb landscaping LawnSite Silver Member
    Messages: 2,205

    my br400 cap has a hole in it to releive pressure. try a new cap and see if it still happens
  7. thelawnguy

    thelawnguy LawnSite Silver Member
    Messages: 2,411

    Okay, I have an older Stihl trimmer with vented fuel cap. Always dumped fuel on everything. Stihl came out with a revised style cap. Was okay for a year then that one also leaked. Last fall they came out with yet another revised part number for a fuel cap, so far this one has not leaked at all (no hole in the top but vents thru a baffle around the threads) so stop by your dealer and spring the six bux for the latest version of the vented fuel cap.

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