Snowpeak Fill probe leak fix

[JimD]

I'm a fan of the SPA P35 which is almost the same thing as the Stoeger bullshark. I have 3 and they are my favorite airguns. Short, light, and accurate. But I do not like the fact that my fill probe leaks when I am filling them. It doesn't stop me from filling them but it wastes some air. Grease on the O-rings helps and might occasionally stop the leak but not for long. My Air Maks Caiman has never once leaked on the fill probe so I know it is possible to do this right.

Today I tried something which has worked so far, 2 fills, to stop the leak. It costs nothing to try. I moved the O-rings on the fill probe and wrapped about 5 turns of all purpose polyester thread around the groove in the probe where the O-ring goes. Then I put the O-ring back. I tried it first with a thicker thread and I couldn't insert the probe. But with a little thinner thread the probe inserts easily and doesn't leak.

If you have a SPA gun that leaks around the probe during fills, I suggest you try this.

 

[Stubbers]

This is a good trick for many o-ring's or rather their grooves to increase o-ring squeeze.

A wrap or a few wraps of teflon/plumbers tape in the o-ring groove.

-Matt

 

[JimD]

I thought about using tape but I worried it would be too thick. But I did not try it. Seems worth a try, it would be easier for my old eyes to see than thread.

 

[Geneeus]

Has anyone tried alcohol? I know it's worked as an emergency repair on cars. It swells the rubber.
Geneeus

 

[JimD]

Well my thread repair only worked for about 10 gun fills. So then I tried teflon tape and it did not work for me. So I tried another thread application and that did not work either. So I had to go back to my oldest SPA fill probe which will seal on the gun but it a little tough to get into and out of the foster fitting on the hose. When I bought groceries this morning I got something for my latest idea.

I bought a $0.99 bottle of finger nail polish at Walmart. You have to look on the lowest shelves to find it. I painted the grooves on the fill probe with it. It took two coats to work. A toothpick helped spread it around the groove without making too much of a mess (but Acetone will dissolve the nail polish if you need to start over). I took the O-rings off and cleaned the probe with Acetone first, then painted on the finger nail polish, then reinstalled the O-rings and put a little silicone grease on them. We'll see how long this lasts. Hopefully a long time. I gave the acetone about 5 minutes to go away and then gave the nail polish at least 15 minutes to dry.

I think lacquer thinner would probably work too. I don't know exactly what will dissolve silicone grease still on the probe but I had Acetone and it seems to work well. I wanted to get it clean so hopefully the nail polish will stay put.

 

[JimD]

I only got one fill without leaking from finger nail polish so it is a bust. I tried again and didn't even get one. So I tried teflon tape several more times without success. I have some water borne poly drying overnight now. If it doesn't work I may just give up on this for awhile. Makes me wish I had a little metal lathe and could just make one with the right diameter in the O-ring groove.

 

[Trucker3573]

I know a stupid question but have you tried new orings ?

 

[coastal drifter]

I'm a fan of the SPA P35 which is almost the same thing as the Stoeger bullshark. I have 3 and they are my favorite airguns. Short, light, and accurate. But I do not like the fact that my fill probe leaks when I am filling them. It doesn't stop me from filling them but it wastes some air. Grease on the O-rings helps and might occasionally stop the leak but not for long. My Air Maks Caiman has never once leaked on the fill probe so I know it is possible to do this right.

Today I tried something which has worked so far, 2 fills, to stop the leak. It costs nothing to try. I moved the O-rings on the fill probe and wrapped about 5 turns of all purpose polyester thread around the groove in the probe where the O-ring goes. Then I put the O-ring back. I tried it first with a thicker thread and I couldn't insert the probe. But with a little thinner thread the probe inserts easily and doesn't leak.

If you have a SPA gun that leaks around the probe during fills, I suggest you try this.

nice! necessity, the mother of invention

 

[JimD]

Yes, I change O-rings fairly often on the probe. I have damaged them a couple times making the groove diameter too big and then forcing the probe. But I don't blame the probe if I damaged the O-ring, I just change it. I have 50 or more in an assortment I bought and some others from Mr. O-ring. Actually I've been using the cheap assortment O-rings, I should try a couple of the better ones. Given the success of the first thread mod and the fact that my old probe works much better I am pretty sure SPA just machined the groove a little too small in diameter. But if the better O-rings happen to be slightly bigger... I've also tried the O-ring spares that came with the gun. They are not high quality but if they had worked I'd be using them.

 

[Florida_Man]

I had issues with my factory SPA probes, but not the probe I purchased from Huma. I now use that probe for my P35, Bullshark, PP700SA, and Notos.

 

[JimD]

Thanks Florida Man. I will try a Huma. I ordered some O-rings from McMaster Carr including some with a 1.8mm cross section but a 3.55mm ID. They'll have to stretch to go over the probe which will reduce the cross section so I decided to waste $5 and try them. I also ordered some Buna N 90 hardness but I doubt they help either. The main thing I wanted was Buna N 70 hardness 4x1.5mm O-rings that are not cheapo Amazon ones. I don't have confidence in any of that but having some good O-rings (100) on hand seems like a good idea. The Caiman uses the same O-rings.

The water borne poly did not work either. The O-ring was too big with it in the groove and I couldn't sand it down and make it work.

I did some measurements on the older SPA probe, a year newer probe, and my Caiman probe. The Caiman probe will not fill the P35 but it does seal in the P35 opening great, the hole is just not in the right position to fill the gun. I used my inexpensive digital calipers.

Caiman probe (seals best) 4.46-4.47 mm diameter under the O-ring, 1.8mm groove width, body of probe 6.9mm
Older SPA probe, 4.48-4.51, 1.6, 6.95-6.98 body
Newer SPA probe 4.37, 1.65, 6.95 body.

I think the newer SPA probe is just too small under the O-ring as I initially thought. It's interesting the Caiman probe seals the best but is a little smaller under the O-ring than the older SPA. I tried filing the groove in the older SPA a little wider and got it about .05mm wider but it did not help.

It's worth a few bucks to me to get a probe that works reliably. I've tried messing around and I am not getting anywhere.

 

[JimD]

Are you sure it's a Huma fill probe? I just searched their website and I cannot find it.

 

[JimD]

I got some O-rings from McMaster Carr (one day delivery for no extra charge) and have a "maybe". It came this afternoon and I had choir practice to go to but I still tried them. I ordered a smaller O-ring that was thicker and it stuck out too much and the probe would not go in. I bought the stock 4mm/7mm 70 hardness O-rings and they seem to work like the cheap ones. The "maybe" is the 4mm/7mm 90 hardness ones. They were a major pain to install but one fill with them (so far) was pretty good. There was a tiny bit of air escaping but it did not stop me from filling to 250 bar. I need to try them in my other probes and do some more fills. They should hold up due to the 90 hardness. I'd still love to get a probe working like my Caiman probe but if one will just fill consistently like this first fill today it would be OK. A little wasted air from the bottle but the guns can be fully filled.

 

[JimD]

Seems like the 90 hardness O-rings have fixed my issue. I've filled multiple times with them on the probe and it works as well as the fill probe on my Caiman X. It does not leak. The 90 hardness O-rings are much harder to get on the fill probe but other than that, they are great. The fill probe I fixed has a better foster connection than the older one that seals better with 70 hardness O-rings and also better than the foster part of the Caiman X probe. So now I have a good probe. If you have a fill probe that leaks, I think you should try some stiffer O-rings.

 

[JimD]

I have another good option for anybody with a leaking SPA or Bullshark fill probe. I bought a new one from Aliexpress about the time I ordered the O-rings. I do not know how to post a link but it showed up in an add for Alliexpress after I had google searched for a SPA fill probe. Cost was less than $10 delivered. It showed up a day to two ago and I just used it to top off my P35-22. Works great. Doesn't need 90 hardness O-rings.

 

[Florida_Man]

Are you sure it's a Huma fill probe? I just searched their website and I cannot find it.

I know for a fact I bought it there, but it appears they stopped selling them. I bought it when I bought my PP700SA 4 years ago, it’s the same size as the P35. That’s a bummer. Sorry, I didn’t know they stopped producing them.

 

[Florida_Man]

I have another good option for anybody with a leaking SPA or Bullshark fill probe. I bought a new one from Aliexpress about the time I ordered the O-rings. I do not know how to post a link but it showed up in an add for Alliexpress after I had google searched for a SPA fill probe. Cost was less than $10 delivered. It showed up a day to two ago and I just used it to top off my P35-22. Works great. Doesn't need 90 hardness O-rings.

Nice. The two options I found on aliexpress both look the same.

Just found this amazing item on AliExpress. Check it out! $1.82 | New Air Filling Adapter Fill Probe 8mm Quick Fitting Artemis Snowpeak M16 , P15 , P35 , PP800 , PR900

https://a.aliexpress.com/_msJqGnE

 

[Florida_Man]

I was about to send you an extra Notos probe I got with my new rifle that I’m not going to use.

The two are my huma, long is SPA and short is Daystate/Brk. The single is what comes with a notos.

 

[JimD]

The one you linked looks like it is the same as the one I ordered and just got, Florida Man. It looks a lot like my SPA probes which look like your Notos one. For now I will use the one with 90 O-rings because it goes into the foster a little easier. But now I have two good options and I think the other one I got at the same time as the one with 90 hardness O-rings can be fixed up with the same harder O-rings. So I am good for SPA fill probes. At least 2 good ones and a usable one and another that is probably good. Ultimately I may use the one I just got if the ones that need the hard O-rings start to leak because it is a lot easier to install O-rings with 70 hardness.

I must never have tried the other probe that came with the P35-177 or the P35-22 (I bought them in the same order from Krale). I tested it a few minutes ago and it works great. So my total problem was one bad probe. Wish I'd figured that out earlier. Now I have three good probes and one I could use.