Hi, being new to liquid fuel stoves I thought I might have to ask you about this. I was using my Coleman 550B stove today just for the fun of it. After having lit it and boiled a pot of tea the flame was a little weak so I decided to pump up the pressure. At the last stroke I didn't cover the hole and a small fireball shot out of that hole. Is this normal or is it a sign that something is wrong? If it's normal I'll guess I just wont pump it without making sure my finger covers the hole. Thanks.
I have never heard of a flame before but if some vapor leaked it seems possible. An easy way to check the valve in the pump is to pump up the stove a bit and then, without locking the pump down, just keep your thumb or finger lightly over the hole. If the pump stays down, the check valve is working, if it wants to come out on its own, it is leaking.
The pump does not want to stay down at all and if I release my finger there's air coming out that smells strongly of gasoline.
It sounds like the check valve ball is gummed up. You might try emptying the tank then squirt some type of penetrating liquid into the pump tube and let it do its work. I had a check valve that was doing the same thing and I ordered a new one for my stove. after I had pulled the old one out I found it to be coatd in almost a varnish type coating. If I would have done what I just stated I could have saved some $$$$.
Do I need some special tools to get the check valve out? I can only get part of the pump assembly out. Guess this should be move to the fettling forum... I didn't know it was going to turn out a fixing job.
Someone recommended a gentleman who makes the removal tool which is better than the one sold on Ebay but I do not remember the post. Someone may just come along and post the link. Ron
If its just a matter of unscrewing the copper nut I can see in the bottom of the pump tube I reckon I can manage to fabricate a tool for that.
Removing that valve looks easier than it is. It might come out, but don't count on it. I would take Rick's advice first. Just squirt a generous amount of penetrating oil down the pump tube, maybe force a little bit down, and just leave the manual valve open and be patient. There is a little metal ball in there than can work it self loose, if you are lucky. If you have a leather pump cup it is probably a good idea to retreat it in a heavier oil after this process. It is not highly recommended I suppose, but you can use the stove as is, as long as you secure the pump keeping your thumb over the hole. One more thing, you said it smells of gasoline. Are you using automobile gasoline or a camp stove fuel ("Coleman", white gas, etc)?
Thanks, guess I'll have to buy some penetrating oil (WD-40 does that work?) of some short as that nut was lodged quite well in there. I do of course use petrol without additives so that is not the problem.
Are you turning the pump knob to the right after your down pumping. The check valve is not meant to hold the pressure of the tank all the time. The positive lock is the real seal. Try pumping with your thumb over the hole. Then when done pumping turn the knob all the way to the right. Jeff
Sorry I meant to write done not down in my post above. Check out this picture. Your stove uses a similar design to this pictured (530) picture from this Post Jeff
This is how far I get. That last nut wont move so I guess I'll just have to wait and see how the penetrating oil does.
Is there a trick to empty the fuel from these stoves? I'm guessing I shouldn't run it with lots of penetrating oil mixed in the petrol.
If you've used WD40, I wouldn't worry about it. WD40 works well for starting fluid for diesel engines. Bob
Thank for all the help. The ball in the valve seams to be working a bit better now (I can hear it working). It still isn't perfect, but it's good enough that I feel I can use my stove again.
A tiny bit of carb cleaner in the fuel may help. My 111t started leaking a bit from the jet when the stove was shut off. I ran a tank with carb cleaner & its been fine since.
I had the same issue today. A flame shot out through the hole in the pump. I took the pump assembly apart and the check valve moves freely. However the black o ring at the top of the threads of the valve assembly is broken. See attached pic. Any suggestions on how to properly replace that?
Do you mean a better fix than replacing the O-ring with another one bound to break again at some point?
If you use a good quality Viton o-ring and a drop of oil to lubricate it, and if there are no sharp edges or burrs where it seats, it should last as long as the rest of the stove. That neoprene pump cup would be immediately replaced with a leather one if it were my stove.
in my 550 I replaced the Oring with teflon plumber tape on the threads, it works and it make an easier job when you got to unscrew the NRV
