Benjamin Hand Pump - Sun Optics Repair Instructions

[Bruce Jarrett]

The brass cap on the end of the filter is the brass screen that was on the pump. It is a screen that helps block the moisture but apparently it doesn't do a very good job. If you look inside the filter I added it has the same screen on both ends that hold the Desiccant material in. I added it to the end of the filter just to add some protection and to make it look better and because if I left it off I would probably lose it. It doesn't restrict the flow. I blew through the unit before I put it on and it didn't require any effort. The pump also feels the same pumping.

[Roger]

Ok Bruce, I understand now I just did not see it in the picture. It sound good I agree with everthing you are doing. I will be trying some of the same thing. Also what kind of silicone grease should be used? Like the kind you find at the auto parts store? The last time I talked to Dwayne he said he was getting some different air filters and he would send me some. Have not seen them yet. I am looking forward to all the feed back on this.

shoot straight
Roger

[Bruce Jarrett]

I don't know what grease would be best because I'm not an engineer or chemist. I was saying that we may be able to go back to silicone if this solves or reduces the moisture problem. The manufactures including Crossman warns against petroleum-based products, page 6 of Marauder manual, and on web sites like the Hill pump web site. The Hill web site has a silicone grease for their pumps. I have never experienced a problem with petroleum in high pressure but if companies say no I would rather take their word for it. I used the Full Syn in my pump when it failed because I felt safer then regular motor oil but It may be just as bad or unsafe. Again not being an engineer or chemist , I don't know. It just seems logical to me that anything that is in that pump will eventually be blown into the air reservoir of the rifle and from there to the barrel of the rifle. If Sun Optics is sending you a filter you should wait and see. Post some pictures when you get it. When my pump was failing I called Sun Optics and he seemed like a real nice guy and said he would send me some o-rings but the post office must have lost them because Sun Optics is only about 1.5 hour drive from my house but it's been a week and a half and no package yet. I got my o ring for P30 from O Rally auto parts.

[Roger]

Yes Bruce,
I agree with you about using motor oil on the pump! The first time I talked to the people at Sun Optics I express my concern about using oil,but they said it was ok. I still have concerns! The last time I talked to Dwayne he asked if I was using enough oil, and suggested using more! My God man how much is enough! Until it is running off the pump and on to the floor. As I said before, I calld because I ran out of p 30 rings, he sent them right away have not seen the new filters as of yet that was some 5-6 weeks ago. So I guess I am just about ready to replace the p30 ring again! I think I will give him a call. I had an old Swede pump that had the Air Force name on it , it lasted for over 10 years. They wanted $100 to replace all o rings in it. I thought heck for another 75 I would just buy another pump that was the first of the year. The maintenance on the air force pump was do nothing, do not put anything on do not wipe anything off!!! As I said it lasted for 10 years with heavy use on two pcp guns. Oh, and by the way Sun Optics told me they were building the Air Force pump now.

I did not mean to quiz you on which silicone grease to use I thought you may have known from pervious inquiries. I do feel you are on to something with the filter. Each time I take my pump apart it is full of water so that problem has got to be address.

shoot straight
Roger

[Bruce Jarrett]

Roger
I would think the grease that you can get at a dive shop would work and be safe because they use o-rings and high pressure. It should be cheaper then the grease from Hill pumps. As I stated before all these pumps including the Hill pump look like the same designed, using what looks like the same parts . I base this on looking at the parts diagram of the different pumps. I think by putting a filter on the Benjamin pump and maybe better o-rings we will have as good ,or close to it, a pump as the Hill pump and a lot cheaper.

[Roger]

Bruce,

I have a call in to talk to Dwayne. I hope he calls before I go to work. I will ask him about the new filters.

I do have divers silicone grease form years of shooting pcp guns. I think I will hold off until we find out how things work.

If you do not mind I will ask him about your idea?


shoot straight

[Bruce Jarrett]

I don't know if you are asking about my filter idea or lube or o -rings but what ever you were asking my permission for go ahead and get all the info you can and share with him . Ask him the material type of orings he uses and see if he knows the type Hill uses. I talk to him twice about my o rings and eventhough I still don't have them I hate to bother him again.

[Roger]

I have not heard anything as of yet. Getting ready to go to work. He has my cell# so I could hear something on the way. I will ask him lube, filter, and o ring questions.

[Roger]

Bruce, I got a voice mail form dwayne from Sun Optics when I was at work. He said he would be gone for the rest of the day and for me to call him in the morning. I will ask him all the things we have talked about. As far as I am concern he has a faulty product and he needs to talk to everyone with a problem. He is lucky someone has not talked about a class action. I have a new stock from Rob Taylor and I need to shoot some with it tomorrow and let everyone know how it feels .

shoot straight
Roger

[Bruce Jarrett]

I wouldn't get upset about this,half the products I buy after using them I can see something I would change. From looking at it when it was apart I think the pump is a good pump and with a filter it may be a great pump. I have only been in pellet shooting for a month so I don't know the history but it seems to me that even the Hill pump came out first without that filter on the outside and later added it. Again not knowing the time line of pellet shooting ,these pumps may have been fine when shooting pressures were lower and when the pressures rose the flaws appeared. Even though I still haven't got my o ring package It seems from reading the threads that he sent out a lot of free parts so he is trying to help. When I had a bad barrel on my rifle and Crossman was very easy to work with on getting free parts to correct it that was a pleasant change from other companies that just deny responsibility. Since he told you he would send you a filter and I assume that was free , he is trying to fix a problem. As far as the oil and high pressure goes it may not be a problem at the slow pace we are applying. A person can't pump very fast so it may not be a problem at these slow speeds. Was there any other info in the o ring package he sent you besides the pages shown at the beginning of this thread ?