Cure for corrosion in the 397/392?

Cure for corrosion in the 397/392?

Joined: September 12th, 2010, 8:18 pm

December 26th, 2011, 10:40 pm #1

I bought a new Benji 397 for my grandson for Christmas because I've read good reviews on how durable they are with pretty good accuracy too.
No sooner does he have it, now I've been reading about problems with corrosion with the valves&spring and parts, more so with the newer Benji's now that they're using aluminium instead of brass for parts.

What is the best way to keep it well oiled to prevent the corrosion, where on the gun should oil be applied?

I sent a small tube of pellgun oil with the gun but what else can be used for lube in larger quantities?

And last but not least, how easy are the 397/392 to work on. Dismantle clean up the valve/springs/seals etc....

PS. Where can I get "upgraded" after market parts if needed?
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Joined: January 4th, 2010, 4:13 am

December 26th, 2011, 10:56 pm #2

Two of my 13XX's have had this problem. What I am trying out is a light coat of vaseline on the internals
I haven't opened either of them yet but will report here when I do. So far so good no sign of dieseling or
sludge coming out of the barrel. Vaseline seems to be inert as far as attacking o rings etc. but it is
flammable so its wait and see time for a while longer.
I haven't been using these as much lately which is why I haven't opened them yet, this being due to
wife's cancer surgery and ongoing recovery. Things are looking real good but these things take time.
Right now spring is looking good for hobby time. Will try to get in some trigger time when I can.

I BRAKE FOR BISCUITS
and TRAINS
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Joined: September 8th, 2009, 1:53 am

December 26th, 2011, 11:42 pm #3

I bought a new Benji 397 for my grandson for Christmas because I've read good reviews on how durable they are with pretty good accuracy too.
No sooner does he have it, now I've been reading about problems with corrosion with the valves&spring and parts, more so with the newer Benji's now that they're using aluminium instead of brass for parts.

What is the best way to keep it well oiled to prevent the corrosion, where on the gun should oil be applied?

I sent a small tube of pellgun oil with the gun but what else can be used for lube in larger quantities?

And last but not least, how easy are the 397/392 to work on. Dismantle clean up the valve/springs/seals etc....

PS. Where can I get "upgraded" after market parts if needed?
2 questions...can you link that thread about corrosion? and do any aftermarket parts makers offer brass replacement parts? I was all ready to build a 1322, but now I'm gunshy
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Joined: January 4th, 2010, 4:13 am

December 27th, 2011, 1:46 am #4

The bulk of the thread in the link is taken up by an individual representing his solution to this
problem. I have no experience with the products promoted there and cannot express an opinion on his
product. I have used transmission oil and air tool oil but apparently not in sufficient quantities
to protect the valve.

http://www.network54.com/Forum/275684/t ... +pump+guns

I will definately have to open up one or both of my older 13XX's soon and take a look to see how the
vaseline is working. I just don't see how we can get away without a regular scheduled tear down clean
and lube,otherwise we will be tearing down and replacing valves anyway. I don't mind the work but
I sure wish that the brass valves were still available.


I BRAKE FOR BISCUITS
and TRAINS
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Joined: December 14th, 2010, 5:08 am

December 27th, 2011, 8:50 am #5

i just got a brand new 2240 for christmas and it has a brass valve. i thought they quit making brass valves or is that just for the pumpers? the two 1377 ive bought have aluminium valves
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Joined: August 3rd, 2008, 2:29 pm

December 27th, 2011, 2:02 pm #6

the valve in the 13xx guns alittle over 10 years ago but are still using brass for the valves in the 2xxx guns

TOO many freaks and NOT enough circuses
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Joined: September 13th, 2005, 8:22 pm

December 27th, 2011, 2:16 pm #7

I bought a new Benji 397 for my grandson for Christmas because I've read good reviews on how durable they are with pretty good accuracy too.
No sooner does he have it, now I've been reading about problems with corrosion with the valves&spring and parts, more so with the newer Benji's now that they're using aluminium instead of brass for parts.

What is the best way to keep it well oiled to prevent the corrosion, where on the gun should oil be applied?

I sent a small tube of pellgun oil with the gun but what else can be used for lube in larger quantities?

And last but not least, how easy are the 397/392 to work on. Dismantle clean up the valve/springs/seals etc....

PS. Where can I get "upgraded" after market parts if needed?
I made a post a couple of years ago on this same subject. I really don't think it makes much difference if the valve is aluminum or brass. I think it is the crappy srping that Crosman is putting the valves. When the spring starts to rust, it flakes off little chunks of hard rust particles and gets on the check valve and it will not seal anymore. If that valve spring was stainless steel or somehow anitrust treated, I think the problem would be solved. It still needs to be oiled genoursly though. Remember the old Sheridans have bronze valve springs and lasted 30-40 years if well taken care of.

Bob in WV

Never get in a hurry, it only slows you down.
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Joined: September 25th, 2006, 2:19 pm

December 27th, 2011, 4:14 pm #8

Could be that only some aluminum valve parts are slipping thru the process which are not completely rinsed of the coolant used when machining them.

The assembly department would not be aware of this dried coolant residue which lays in the threaded area, o-ring groove or other undercut surfaces. But when the assembled valve is in service and is exposed to moisture, the coolant residue which has not been rinsed away will reactivate and cause corrosion.

I have observed coolant types which did not attack steel, brass or other non ferrous metals, quickly corrode aluminum.

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Joined: January 4th, 2010, 4:13 am

December 27th, 2011, 10:28 pm #9

I made a post a couple of years ago on this same subject. I really don't think it makes much difference if the valve is aluminum or brass. I think it is the crappy srping that Crosman is putting the valves. When the spring starts to rust, it flakes off little chunks of hard rust particles and gets on the check valve and it will not seal anymore. If that valve spring was stainless steel or somehow anitrust treated, I think the problem would be solved. It still needs to be oiled genoursly though. Remember the old Sheridans have bronze valve springs and lasted 30-40 years if well taken care of.

Bob in WV

Never get in a hurry, it only slows you down.
I BRAKE FOR BISCUITS
and TRAINS
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Joined: April 12th, 2002, 5:26 am

December 28th, 2011, 1:40 am #10

Could be that only some aluminum valve parts are slipping thru the process which are not completely rinsed of the coolant used when machining them.

The assembly department would not be aware of this dried coolant residue which lays in the threaded area, o-ring groove or other undercut surfaces. But when the assembled valve is in service and is exposed to moisture, the coolant residue which has not been rinsed away will reactivate and cause corrosion.

I have observed coolant types which did not attack steel, brass or other non ferrous metals, quickly corrode aluminum.
aluminum, badly corroded, had to toss the part. These were guns from the 50's through 70's, I'd guess..you'd think crosman would have learned aluminum valves don't work well in pumpers the FIRST time.
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