FT Piston seal life.

[Cross Pistol Packer]

After maybe 90 shots,most of them at 15 pumps,the piston seal is shot on my 1389,was fine last time used,just fitted 2 brass M4 nuts & washers today on the pump arm pin (the acorn nuts were always working loose) tried to pump gun,no go.
So you pumpers out there,how long does your FT piston seal last ? (mines a AC custom job)
Ray...

[1377x]

mine didn't last long at all . like you i did 15 or more pumps at a time
i switched to the 130 piston hoping it lasts longer than the o-rings

[Cross Pistol Packer]

Thanks for that info Noob,what is the best material for pump seals ?
Will get a bag full in.
Ray...

[Cross Pistol Packer]

May well be worth asking here what seal lubrication seems best for long life seals,I am using SAE 30 ND oil..
Would synthetic lube be any better ?

[eric]

i might get $hit for this but mine from AC fried the seals way too quick in my opinion.i switched one out and put a new one in and within 10  to 15 shots at 10 pumps the new seal was fried again.i think the seals are too small for the amount of heat created when pumping .i had another one with a seal the size of the outer valve seal and that lasted well over a year with heavy use.i don't think lube will help these little seals.maybe somewhere in the realm of 90 durameter might be better or a larger o ring .maybe we could convince AC to change something with his pistons other than the short life they are nice.i am done with the 13xx series guns now so either way not a problem   

[Cross Pistol Packer]

Thanks Eric,I brought two pistons from AC,may try to cut deeper seal groove on my spare & go for more heavy duty o-ring.
Ray.

[Plasticman]

I don't pump my gun 10 pumps but I have over 500 shots on the same O ring. Make sure there are no rough spots inside the tube. Polish ot the tube with 600 or finer grit paper. Then clean it out before you put the piston back in.

[1377x]

Thanks for that info Noob,what is the best material for pump seals ?
Will get a bag full in.
Ray...

that i don't know
on ac site he says the o-rings are 90 durometer  which is pretty hard that what is used for pcp applications
i think i used some vitron 75 durometer on my ac piston i know on my c mellon piston i used the vitron 75 o-rings 30sae oil and it lasted through a tin of 500 pellets 10+pumps at a time
on my 130/1377 piston again i don't know what material it is the batteries are dead in my camera so i can't post a new pic here's a pic of another 130/1377 piston i sold it has a different material than my new one but like it better than the new stuff.im going to get another 130 piston head with the other material and do a pump test

[eric]

1377noob   how big is the o ring on the one from charlie --- is it larger than the one from ac ? i still think ac's is too small . i could switch between the o ring on the outside of the(13xx)valve and the other piston i had and would have no problems .i replaced 2 of ac's with in 5 sessions --- the 2nd one only lasted 150 pumps --- 15 ,10 pump shots.it needs a bigger o ring unless folks like to tear apart their guns every session to replace those pesky little o rings .1377noob    another question --- where did you get your 130/1300 piston seal from and what was the cost ?

[Cross Pistol Packer]

Eric,will the larger valve seal fit straight on AC piston without re- cutting piston seal groove ?
And what is material and size valve seal ? might be able to source one locally.
Cheers.
Ray.

[1377x]

eric,
the o-ring on the mellon piston(a-111 or a-113)(7/16 ID X 5/8 OD X 3/32 W -9/16 ID X 3/4 OD X 3/32 W) is larger than the ac piston.the mellon 0-ring lasted a good bit longer than ac's but did eventually go.when i switched o-rings on the mellon piston i used vitron 75 o-ring it was either (a-111 or a-113) using 30sae non-detergent oil it lasted until i sold it which was about a 500ct/tin
i gave up on the flat top pistons for now.
i get my 130 piston seals locally,he has some black,white or clear material.so far i tried the clear and white liking the clear better.the cost is around $2-$5.i usually have him make me a complete piston and that runs me $15 installed

CPP,
if you can find a variety pack of vitron 75 all sizes or some 90 durometer variety packs,you would have a good start.here i got the v75 pack from harbor freight tools,i now get my o-orings from
http://www.theoringstore.com/servlet/StoreFront
you could also check ebay i have seen them there,too

[eric]

Eric,will the larger valve seal fit straight on AC piston without re- cutting piston seal groove ?
And what is material and size valve seal ? might be able to source one locally.
Cheers.
Ray.

nope,i tried .i don't have the means to make the groove bigger with out totally mucking it up .some one with a lathe or some decent shop tools could probably get it done pretty painlessly.maybe some one here could help      

[eric]

eric,
the o-ring on the mellon piston(a-111 or a-113)(7/16 ID X 5/8 OD X 3/32 W -9/16 ID X 3/4 OD X 3/32 W) is larger than the ac piston.the mellon 0-ring lasted a good bit longer than ac's but did eventually go.when i switched o-rings on the mellon piston i used vitron 75 o-ring it was either (a-111 or a-113) using 30sae non-detergent oil it lasted until i sold it which was about a 500ct/tin
i gave up on the flat top pistons for now.
i get my 130 piston seals locally,he has some black,white or clear material.so far i tried the clear and white liking the clear better.the cost is around $2-$5.i usually have him make me a complete piston and that runs me $15 installed

CPP,
if you can find a variety pack of vitron 75 all sizes or some 90 durometer variety packs,you would have a good start.here i got the v75 pack from harbor freight tools,i now get my o-orings from
http://www.theoringstore.com/servlet/StoreFront
you could also check ebay i have seen them there,too

can you say where there is a source for those interested in getting their 130/1300/760 up and running again ??

[1377x]

can you say where there is a source for those interested in getting their 130/1300/760 up and running again ??

for those interested in getting your old crosman 130/1300 or any(old and new alike) crosman airgun up and running again, there is a great repair shop that does very good work .he has been repairing crosmans for more than 20+ years and his rates and turn around time  very reasonable.
he specializes in older guns i have seen him doing the old benji's soldering and all
i believe he can repair all airguns from the louis and clark(saw that one also) to the new ones
i'm in his shop quite a bit and have seen some very interesting rigs
here's his site so if you need something repaired give him a jingle
http://www.b-bsupplyco.com/

[eric]

thanks that's some good info