New(er) Optimus Nova pump fitting replacement

Hello,

I am just curious if anyone has disassembled one of the newer Nova pumps with the "bayonet" fitting. The only schematics for the Optimus Nova pumps I have seen on their website refer to the older style pumps. I am trying to make a replacement pump for my older Brunton Optimus Nova and wish to replace the newer female fitting on the pump with an older CEJN fitting. I have been in contact withe katadyn/optimus customer service but they want to replace the fuel line/male fitting on my older stove so it is compatible with the newer pump. Cheers

 

I haven't a schematic of the newer Nova pump, but I wonder if the CEJN female fitting you want to graft onto it has a one-eighth-of-an-inch BSP thread on it like the one I used to get an Omnifuel pump to fit an older Nova?

Topic in 'Frankies, Mods and Hybrids' column

John

 

I have a new Nova pump/hose assembly which I will investigate later today.
G

 

This begs the question: What happened to the original pump? Did it fail? If so, how?

Not sure this would help, but there are some new Brunton pumps on the evil bay right now for a pretty decent price. Last I checked they still had 4 available.

Thanks,

Mike

 

I suggest contacting brunton. I've had good luck with their customer service.

 

Niether brunton or optimus will be able to help with this anymore. The novas with the old fuel line are out of their 5 year warranty and optimus sold on all their spares. You need to email around suppliers like base-camp and fogas etc. Or just buy a cejn coupling and plug and do it yourself. Optimus can only supply you with a fuel line and coupling in the new style which is probably better anyway (now they have got them sorted out).

 

Brunton pump pictures:

If it's silver, it's aluminum, orange, it's plastic (probably nylon-filled). I don't know what the thread for the opening is but it measures at an inside diameter of 0.250 inches. Could it be a 1/4 - 28? That seems too easy and is unlikely since it's probably metric or something weird. Anyone have the stove or hose it mates to?

Nova pump pictures:

The black head on the pump is metal (I assume aluminum) and seems to be anodized black. In fact, the whole dang pump seems to be metal - even the pumps fuel knob. Classy. 8) The connector is a push and turn 1/4 style connector which seems solid though I've not tried the gear yet. It's awaiting use in a project. The hose is the standard Nova thread of M8 x 0.75. It fits snugly but correctly on two Novas I tried it on. Leather pump cup. A really solid, super-duper pump. I tried to remove the female connector that is "threaded" into the pump head. It gets tighter as I try to spin it off. So, I thought, hmmmm, maybe reverse threads? I tried the other direction and it gets tighter that way, too. I don't want to bodge it up since I have a use for it, so you are on your own. It doesn't really feel like a thread to me. Very odd.

Hope this helps. Not sure what the Nova pump with hose is going for, but I like it enough to go find out as I might like another.

If it 'twere me, I'd go for the complete change-out and dump the CEJN connector. Your mileage may vary.

Cheers,
Gary

 

I was hoping that pump would fit the male threads on the CEJN 141 qdc and be of some help. If not, sorry if I went down a wrong path.

Yup the Nova pumps are built like tanks.

I personally wouldn't trade out the CEJN coupler on mine for anything. But then, mines never given me any problems. Knock on wood. Has anyone used any Beswick Engineering couplers? They appear to be of like quality to the CEJN.

Mike

 

Sorry I'm too chicken to undo the connector. 'Spose it could be something I build up to and try one of these mornings when I'm more awake...

Why not drop Beswick a call or an email and see what they'll quote you, Mike? Those connectors look remarkably like the CEJNs. Maybe they'll be cheaper. I bet you could get some fellow orderers from here at CCS.

 

BD, you're not chicken, just prudent. I wouldn't do it either. It would suck to give it a turn and SNAP!

I called Beswick a couple years ago and they needed specific thread and application before they would give me a quote. They were very pleasant and said viton or nitrile seals would be no problem. I didn't have the info handy and I got deployed and never followed up. I wanted to get all the hose and crimp sleeves etc. before I called back. I've looked around and can't find the proper hose. Does anyone have a source for the small diameter braided hose like that on the original Nova or new Muka? I seem to recall someone saying the Muka's hose is more flexible, which may or may not be a good thing. I'm more concerned with durability than flexibility, though a combination of the two would be ideal.

Mike

 

The cejn connections are screwed in (not reverse) with some locking sealant, there is also an o ring behind it. I assume the newer connections are the same. Rectuus 20 couple have the same thread and would also work, they are smaller. The problem is, for me anyway, crimping the pfte fuel line.

I agree with Gary about changing to the new connection. If you ever rupture a fuel line you will be very pleased you can turn it off at the tank.

Dan

 

Dan, are you willing to bet BD's pump on your assumption? I THINK you're probably right, but........

Are these teflon hoses? I'm not curious enough to cut into one. They make aluminum and brass crimping sleeves and fairly inexpensive tools to crimp them.(as well as VERY expensive ones) I can only imagine what kind of pressure you'd need to rupture a stainless steel braided line. The chances of one rupturing are minute in my opinion. Then again, I'm careful not to kink or bind hoses and cords. I also inspect my stuff pretty thoroughly. I also prefer the smaller footprint of the original pump. I consider it a safer and more solid design than that of any of it successors. I'll let the recalls speak for my reasoning.

RonPH and I have identical stoves from the same lot. I hope that his has performed as flawlessly as mine.

In case I caused some confusion, the orange pump that BD has pictured appears identical to the one on evilbay, but is most certainly NOT the pump that came with any Nova stove. Simply thought it may be a cheaper substitute that could be made to work with the CEJN coupler.

Mike

 

Hi Mike

It is an assumption but it must be correct as the first post here says optimus offerd to replace the old coupling with the new version. I am pretty sure there is a topic some where here where articflame discusses this (nova recall thread I think).

The orange pump is a brunton bantam pump. The brunton nova pump was an optimus cejn pump. The brunton bantam pump looks the same as the kovea booster clam pump, I am sure kovea made both. There is a Chinese clone version on ebay also.

The hoses are teflon and very strong. I ruptured mine by spilling some meths when priming. That little pool of meths lit and melted the hose. Easy as that. I also think if you kinked the hose it would be stuffed.

It is hard to crimp as you need to go under 6.5mm, it seems most clamps stop at about 7mm? Re-crimping with thicker nitrile is easier but the fittings are not barbed that well for rubber.

Dan

P.S. I know very little about crimping and fuel lines.

 

Hey Dan, the way I read it, it sounds like they want to sell him a new hose with the new bayonet fitting because:

a. The male bayonet fitting is already assembled on the replacement hose that is currently in production now and are far cheaper. I don't think they are trying to sell him the female bayonet connector that's on the pump just the hose and male fitting pre-assembled.

b. He won't have to disassemble the pump fitting risking possible damage and leaks from an improperly prepared threaded connection made by a consumer who's mechanical abilities are unknown to them, whereas, if they send him the hose it will match the new pump, which, it sounds like, he already has.

c. The hose assembly can be replaced with the tool that came with his stove using a procedure that is detailed in the filter replacement procedure in the instruction manual.

d. You said in a previous post that they no longer stock what he's asking for.

This is based on MY assumption that:

a. He has an older Brunton Optimus Nova(identical to mine) that was all stainless no black or green that came with the all aluminum pump with CEJN 141 series coupler.

b. He's already in possession of the newer pump assembly.

c. All he wants is to unscrew the bayonet fitting and valve assembly from the new pump and install the female CEJN 141 coupling in it's place.

His/my model was not subject to the recall, but I am curious as to what happened to his original pump. I am concerned for him because he must have been in a nuclear blast to ruin that pump.LOL

On the hose, I haven't personally crimped any hoses this small either. I have several clamp type flaring tools that I was planning to use for the crimps. I've had very good success wrapping stainless steel wire around the barb area of the hose on other models in lieu of a swaging sleeve. Perhaps it's a bit more difficult than I'm imagining. When you used the term "rupture" I equated that with "burst".

You must have REALLY wanted it primed well! LOL I think ptfe is stable up to around 400F not sure how the strength properties are at that temp though. Meths flame are near impossible to see in daylight too. I'll log that one for future reference.

Mike

 

Hi Mike, That sounds about right.

The spilled meths was really silly of me. I was working on a generator for the nova so it could run kero with a nova dog cap. I lit the stove oodles of times as I worked on it. I got a bit slack with my priming! But I did get the nova to burn kero very well with the cap. That is what my avatar is.

If you ever do crimp a nova fuel line please post a pic or two.

Dan

 

Hi.

https://classiccampstoves.com/posts/165642

The biggest problem is sourcing of the CEJN couplings.
The last ones I bought went over the pond to Gary


juergen

 

HA! Thanks Juergen!!

Well there you go. That link just saved me a headache.

Ok Gary, that's about as big a green light as I've seen in a long time. If you don't do it now, you ARE a chicken.

Actually Juergen, the biggest problem, is the price of the little buggers.

All that typing for nought.

Mike

 

Price?
What price?


Let me put it this way: It had been kind of a bargain....
But unfortunately I'm out of parts. I gave everything to Gary, just ask him....

juergen

 

Oh, rats! I'm outed!

OK, Mike. I might have one left.

I'm off to disassemble the pump. Thanks for the reminder post Juergen. Totally forgot about that post. So much here at CCS to forget about because there's so much here! And, for the public record I believe there were a collection of custom caps that went your way in trade for those sought after parts?

Mike, I'll drop you a PT in a bit.

Cheers,
Gary

 

Point for You!


And btw, the caps are just great!

juergen