BRNO Aeron B98 PCP Repair

[Dulcmrman]

Hello to all,

I'm a new member and I'm looking for someone to do some repair work on my Aeron B98. It's a five shot PCP repeater made in the Czech Republic and I SUSPECT it's not longer made. I bought it years ago from Don Nygord to help me practice NRA Bullseye timed and rapid fire.

Lately it has started leaking. Both cylinders hold air when NOT attached to the gun, but both also leak to zero overnight when attached to it. I found an outfit in the United Kingdom who sold me a rebuild kit comprised of the O-rings I needed to do the rebuild. Yesterday and today I disassembled it, replaced the O-rings, and put it back together. Unfortunately, it now leaks to zero in seconds, so I obviously messed up somewhere along the line. I've decided the job is beyond my skill level so I'm now looking for an a gunsmith experienced with this gun to do a rebuild and put it back into operating order.

Is there anyone here that does such work? Does anyone know of someone who can do the work?

I look forward to tapping into the collective knowledge of those on this site.

Many thanks in advance,

Dennis
Prescott, AZ

 

[STO]

I don't mean to patronize you by suggesting the obvious, but did you try cocking it before filling it with air? It is an easy little thing to miss. 

 

[marflow]

sorry I'm not going to much help on your B98, I do have a B96 but a different animal

so if the cylinders are fine and you have a small leak and I assume that was at the valve and now you are dumping air at the valve area still but worse

when you screwed the cylinder on did you cock the pistol, the hammer could be holding it out

I think you have just one problem the valve is not closing but the why is unknown to me

could you have put something in backward, did you take lots of pictures and do you have owners manual that has the parts diagram

 

[AirNGasman]

Check with Steve at Pomona Airguns.

 

[Dulcmrman]

sorry I'm not going to much help on your B98, I do have a B96 but a different animal

so if the cylinders are fine and you have a small leak and I assume that was at the valve and now you are dumping air at the valve area still but worse

when you screwed the cylinder on did you cock the pistol, the hammer could be holding it out

I think you have just one problem the valve is not closing but the why is unknown to me

could you have put something in backward, did you take lots of pictures and do you have owners manual that has the parts diagram

Thanks for your input, marflow. I did take lots of pics and I THINK I was careful to assemble it correctly. However, Murphy's Law always pertains. Another poster suggested I ensure it's cocked before putting the tank on and I'm certain I did not do that, so back to the bench for another try.

 

[Dulcmrman]

I don't mean to patronize you by suggesting the obvious, but did you try cocking it before filling it with air? It is an easy little thing to miss.

Thanks, STO. You aren't patronizing at all. I did NOT cock it before attaching the cylinder, so it's back to the bench this morning to try that. I didn't realize that was necessary. I'll post again after trying that. Thanks again for your advice.

Dennis

 

[Dulcmrman]

Check with Steve at Pomona Airguns.

Thanks, AirNGasman. As suggested above, I SHOULD HAVE cocked the gun before attaching the cylinder. If that doesn't work, I'll contact Pomona Airguns.

Dennis

 

[Dulcmrman]

I don't mean to patronize you by suggesting the obvious, but did you try cocking it before filling it with air? It is an easy little thing to miss.

Thanks, STO. You aren't patronizing at all. I did NOT cock it before attaching the cylinder, so it's back to the bench this morning to try that. I didn't realize that was necessary. I'll post again after trying that. Thanks again for your advice.

Dennis

Hi again - Well, STO, you were right on the money. I cocked the gun, attached the cylinder, and everything worked as advertised. I just checked it this morning and it held pressure overnight, so it looks like I got it right after all. Thanks so much for your suggestion.

Dennis

 

[marflow]

the hammer setting on the valve is a problem on many gas guns and I think mainly on low power guns but I have heard PCP rifles do the same thing

so I must ask where did you get the O-rings

 

[Dulcmrman]

the hammer setting on the valve is a problem on many gas guns and I think mainly on low power guns but I have heard PCP rifles do the same thing

so I must ask where did you get the O-rings

I ordered the O-rings from SureShot Airguns in the UK. Here's their website.

https://sureshot-airguns.co.uk

After replacing all the O-rings in my Aeron B98 I had several larger sizes left over. Or maybe I missed some? Can't say for sure, but the gun holds pressure with either of the cylinders attached to the gun. The owner's manual for the gun lists all of the O-rings with their sizes, so I'm guessing I could have ordered them on line from an appropriate supplier. However, while sizes are provided, materials from which they are made are not listed in the owner's manual and from what I've read elsewhere this could be an issue. Nevertheless, the kit I received seemed to have a replacement for every one of them I could find. I did re-use four tiny "washers" as the manual called them because the kit did not contain any replacements for them.

Happy to answer any other questions.

Dennis

 

[STO]

I don't mean to patronize you by suggesting the obvious, but did you try cocking it before filling it with air? It is an easy little thing to miss.

Thanks, STO. You aren't patronizing at all. I did NOT cock it before attaching the cylinder, so it's back to the bench this morning to try that. I didn't realize that was necessary. I'll post again after trying that. Thanks again for your advice.

Dennis

Hi again - Well, STO, you were right on the money. I cocked the gun, attached the cylinder, and everything worked as advertised. I just checked it this morning and it held pressure overnight, so it looks like I got it right after all. Thanks so much for your suggestion.

Dennis

 

[marflow]

I would think 70 or 90 buna would be fine for that pistol the sizes could be a problem but I have found a UK supplier that has the oddest of sizes

I would write down the sizes and see what you could find at the O-ring Store

I poked around on that site and never found the kit you bought but it can wait

I'm glad you are back in business and I'm thinking there are few of those pistols in the states

mike

 

[Dulcmrman]

I would think 70 or 90 buna would be fine for that pistol the sizes could be a problem but I have found a UK supplier that has the oddest of sizes

I would write down the sizes and see what you could find at the O-ring Store

I poked around on that site and never found the kit you bought but it can wait

I'm glad you are back in business and I'm thinking there are few of those pistols in the states

mike

Thanks for the additional input. The sizes listed in the parts breakdown are something like this: O-ring (9x5), O-ring (4x1.5), O-ring (3x1), and so on. Knowing nothing about O-ring sizing I researched metric O-rings on line and found that all listed three dimensions, i.e., the outside diameter, the inside diameter, and the cross sectional measurement. I PRESUME that the manual I have is listing the OD and ID, but not the cross section. The O-rings in the kit were OBVIOUSLY of different cross sections so I don't know how I would determine that except by dismantling the gun and measuring, something I'm loathe to do. Bottom line is that the gun works now so I'm a happy camper.

Dennis