Maximus fill valve issue

[ev-in-az]

I got my Benjamin Maximus yesterday. This morning I started to pump it up had a problem, my Hill pump would not connect to the fill valve. The pump has the 1/8" BSPP female quick disconnect which has always worked with my other rifles with foster fill valves.

I contacted Crosman and their suggestion that I order an Air Venturi 1/8" BSPP valve from Pyramyd.

[wll2506]

I got my Benjamin Maximus yesterday. This morning I started to pump it up had a problem, my Hill pump would not connect to the fill valve. The pump has the 1/8" BSPP female quick disconnect which has always worked with my other rifles with foster fill valves.

I contacted Crosman and their suggestion that I order an Air Venturi 1/8" BSPP valve from Pyramyd.

I have the same problem with a few of my fill valves. I usually just lick the valve and it has enough moisture so the Foster fitting internal O ring will slide over the fill valve.  Sometimes they are a pain in the ^%$% to attach.

wll2506

[Back_Roads]

 A thin film of divers silicone grease on the male end helps keep things moving smoothly.

[ev-in-az]

A thin film of divers silicone grease on the male end helps keep things moving smoothly.

I tried that and it didn't work. I got sore fingers trying to mate those two. Apparently the foster nipple on the Benjamin air rifles is a little different than the ones on my other rifles and the Air Venturi Female disconnect fitting works when others don't. Learn something new every day.

Got the Air Venturi Female Foster valve today. Crosman is right it works, slips on easily and doesn't leak. Finally get to fill it up and shoot.

OK, good news and something new. The good news the Air Venturi fitting slips on easily.

Something new: My normal practice is to pump 50 strokes, rest for 15 minutes and pump 50 more strokes -- Hill pump recommended practice.  When I went back for the next 50 strokes it had leaked down to zero. Checked it out on a loose Ninja tank, leaked down in less than fifteen minutes. I have never had to open the bleed valve during rest interval before.

Conclusion: The Maximus fill valve and Air Venturi fitting are a different size than the other eleven foster fittings I have.

It appears the answer is to fit a "standard" ( like the rest I have) fill valve to the Maximus. In the mean time opening the bleed valve during the rest period works.

[wll2506]

A thin film of divers silicone grease on the male end helps keep things moving smoothly.

I tried that and it didn't work. I got sore fingers trying to mate those two. Apparently the foster nipple on the Benjamin air rifles is a little different than the ones on my other rifles and the Air Venturi Female disconnect fitting works when others don't. Learn something new every day.

Just keep trying, the rubber O ring is usually the problem binding up....you are not alone in this situation.

wll2506

[David Mccann]

the end of my disconnect would bottom out at the hex on the male on a couple of mine. had to machine the hex a little thinner, or  more shallow so the balls would get low enough to engage the groove proper and let the collar move to the locked position.. cheers

[vigilandy]

I've got quite a variety of PCPs and have never had a problem when using Foster brand connections (7 or so).  The Air Venturi uses a genuine Foster fitting.  I think the generics must be off spec a little. 

[rsterne]

Never had a problem.... I suspect someone is getting sloppy on their tolerances....

Bob

[ev-in-az]

Never had a problem.... I suspect someone is getting sloppy on their tolerances....

Bob

I've never had a problem before on several rifles, no Benjamins though which was the question Crosman asked and when I said no I got the Air Venturi recommendation. I went on Pyramyd and in the reviews for the Air Venturi fitting there was numerous reviews for it working with the Benjamin Marauder and a Hill pump. No mention of other fittings not working. I'll know when it gets here.

[Sprungout]

Had this issue when connecting a Chinese bull brand pump to a Ninja bottle. Worked fine on my other guns, but wouldn't go on far enough to lock the ninja nipple. Like Bob and Ninja said, improper tolerances stacking up against us. I switched out the female end, less than $10.

[ev-in-az]

From Tom Gaylord:

"Pump incompatibility
You may remember that I reported that my Air Venturi G6 hand pump is incompatible with the Benjamin Maximus rifle. I used the Benjamin hand pump instead, and it worked fine. I did some checking with both Pyramyd Air and Crosman and learned that both of them were aware of some problems. Pyramyd air has made some changes to their male Foster fill nipples, and Crosman just ordered a G6 pump so they can examine it. I think it’s helpful for all of us to know that these companies are working behind the scenes to make their products as universal as possible. That was the first surprise."

Apparently Crosman used a different supplier for the fill valve which is according to my measurements is about 5 thousands (.005) larger than the other 11 fittings I have which is enough to prevent some female quick disconnects from fitting.

My solution was to replace the fill valve with a "standard" Foster nipple.

Not everyone will have this issue.

[vigilandy]

Just want to remind everyone to buy properly specced fittings.  The Foster 12FS is only rated to 2500psi.  Fine for a Disco or Maximus.   If using the fittings for 3k fills like the Maurader you will need the 12FSS.  Who knows what generic fittings are rated for...

[MDStroup]

Wow, that is weird. Niether my original maximus or my new replacement maximus that just came today have a attachment problem with my hill mk3 handpump. After i read this i immediately went and checked it and i have no problems. Then again it doesnt surprise me. My original maximus was littered with problems. Even more than i thought after comparing it to the new one.