Coleman 505A rebuilding

Discussion in 'Fettling Forum' started by iangx470, Sep 30, 2020.

  1. iangx470 Canada

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    So I have a 1978 coleman 505a that i'm trying to return to its former glory. When I tried to pressurize it for the first time, it leaked where the generator met up with the burner bowl part. Upon taking it apart, I realized that my on/off lever isnt fully closing it off causing it to leak when i pressurize it since the system is allowing pressure to flow thus causing my leak (i assume???). How would i go about fixing this? Is it as simple as a new o ring? Any information or direction would be appreciated!

    Also (possibly related), is there supposed to be a little wire hook thing coming out of my generator assembly to my valve? Or is that not a part on these stoves?
     
  2. Blueflame

    Blueflame Canada Subscriber

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    505A Valve Annotated.jpg There are 2 O-rings in this stove. One is on the valve shaft. To replace that O-ring you have to remove the valve wheel and the shaft will pull out. There is another on the fuel/air eccentric. For this one the aluminum valve body has to be removed and the F/A tube can be unscrewed from the valve body. Now CAREFULLY pull the F/A tube out of the valve body. The eccentric is attached to the metering rod and you will see the o-ring on the brass eccentric.
    If fuel will not shut off then it is almost always the F/A O-ring that is defective. A bad O-ring on the valve shaft will cause fuel leak from the valve area. A bit of silicone grease will aid in installing new rings. I don't know the size of the rings but I have a kit with many sizes and pick the ones that work. They must be fuel resistant (viton), brown color or green A/C type .
    Just did one last night.
    There is NO wire hook in the generator tube.What you see is a spring which is there to aid in fuel vaporisation. The cleaning/simmering is done at the device near the burner entrance and is not meant to shut down the fuel flow.
     
    Last edited: Oct 2, 2020
  3. iangx470 Canada

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    that was one of the most informative forum replies ive ever seen! i'll try it out and report back!
     
  4. iangx470 Canada

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    So i've run into a problem. The valve shaft on my 505A looks completely different from the photo. My 505B is the same, and it has the o-rings, but on my older 505A everything is different and i cant even find where there would be any o-rings. Ive included a photo of the stove in question as well as the valve stem pulled out. thoughts? IMG_3418.jpg IMG_3419.jpg
     
  5. Blueflame

    Blueflame Canada Subscriber

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    OK, the tube below the on/off valve has a schrader valve in it. Unscrew the tube...grab it just below the valve to tank threads. You will see the schrader valve inside the top of the tube..It has to be replaced. First heat the tube at the schrader valve area with a heat gun or dip it in boiling water, this is to soften the rubber seal so you can remove it in one piece otherwise it will break apart. With a pair of needle nose pliers or similar tool unscrew the valve. (It looks like a tire valve). The replacement schrader valve must be fuel resistant and can be found at automotive stores. OR send me a message and I will send you the correct valve and a small tool to remove/replace the valve.
    [​IMG]

    The tube you have is similar to the tube you see in this pic ( this pic is from a different stove(s) but same arrangement as your stove)
    BTW...that is NOT a 505A...yours is a 505 no letter...different animal from original post.
    Simple schrader removal cap.
    upload_2020-10-3_17-25-54.jpeg upload_2020-10-3_17-25-54.jpeg
     
    Last edited: Oct 3, 2020
  6. iangx470 Canada

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    its alive! i bought a kit of schrader valves on amazon for 15$ which included the removal tool and i finally got it all working! IMG_3464.jpg

    Thank you so much for your help! now i can hopefully enjoy my stove for many years!