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...
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
Thanks for that info Noob,what is the best material for pump seals ?
Will get a bag full in.
Ray...
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 ?
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 :-[ :(
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.
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.
Quote from: Cross Pistol Packer on November 14, 2010, 05:22:06 PM
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
(http://www.crosman-air-pistol-owners-forum.com/board/index.php?action=dlattach;topic=443.0;attach=721;image)
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 ?
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.
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 (http://www.theoringstore.com/servlet/StoreFront)
you could also check ebay i have seen them there,too
Quote from: Cross Pistol Packer on November 15, 2010, 01:46:29 PM
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 ??? ;) ;)
Quote from: 1377noob on November 15, 2010, 03:39:55 PM
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 (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 ??
Quote from: eric on November 15, 2010, 03:46:29 PM
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/ (http://www.b-bsupplyco.com/)
thanks that's some good info ;) :) :-*
Thanks from me as well Gents,good info indeed :)
Ray...
Interesting that more than one user has a problem with the seals on these flat top pistons... could be this be a problem across the board with other FT makers? I am about to pull the trigger on some mod orders, and I keep finding road blocks such as these.
i would say no. all seals will wear ,some quicker than others.roy from mountainair has been doing this for a while and i havent' hear anything about his pistons and gil is back making some and if you haven't seen his stuff ,it's top notch fer shur
Don't try to use that as an excuse to NOT BUY MORE STUFF ;D ;D ;D Like the man said--all seals wear out..you justt happen to hear about more than one here.......happens everyday to folks all over the world..just VERY seldom that ya hear about 'em..might be caused by improper installation, or not replacing with new, or it just got old and worn out!! Don't let that stop ya from getting on with the projetct that you KNOW you GOT to have :-* :-*
it's the same with the stock pump cup they go,too
the only way to avoid it is to not use it and i for 1 have trouble putting mine down
i found a pic of the white seal for the 130 piston
(http://i613.photobucket.com/albums/tt211/edf73/PB040354.jpg)
and here's the clear it fits the piston better
(http://www.crosman-air-pistol-owners-forum.com/board/index.php?action=dlattach;topic=443.0;attach=721;image)
Good pics Noob,let us know how they perform compared to o-rings for longevity.
Run my vernier over a new seal that came with the AC piston. ID 9.0 mm seal thickness 1.75mm(012 in o ring sizes)
going to buy several seals in different materials and evaluate them in use.
found some standard o-rings at work, NBR 70 shore,quite soft I think,will see how long they last for starters.
will do!
hopefully an o-ring that lasts can be found
I'm not sure what material it was, but I had tried a Yellow one I got from work and it was a waste of time. It only lasted about 50 pumps and was leaking llike a hole in the hoover dam! I noticed that it was much softer than the ones I got at Ace (black). Don;t know what they are, but will ask next ime I go in there. No probllems with them at all.
Rich
in my experience i think im a good part of the problem letting the gun heat up during pumping
I think 90 durometer urethane may work well, Tim at Mac1 Airguns uses these for just about every kind of seal he puts in a gun. Those combined with some of his "Secret Sauce" should last for a long long time I would think.
Trying to lay my hands on some Kalrez o-rings,they can take up to 327 degC and take a lot of stress.
Just tried the standard NBR 70 shore seals,42 pumps (3 at 10,one at 12)seal shot...
Worth a try.
Back to using the 90 shore seals that AC supplied with there piston.
As soon as I can get the Kalrez seals,will fit one to my spare piston.
Ray...
Fitted a Kalrez seal last night as the 90 durameter seal was shot,seems to pump ok but not so hard to pump,FPS was down more than 100fps,it was worth a try.
Have taken a look on ACs site,is the seal on there FTP been improved with larger more beefy seal ?
May well try one of Gmacs FTP in the 1389.
follow-up from nov.'10
i ended up selling the piston with the clear cup to a member here so i dont know how that one is holding up
still using the piston with the white cup,still no issues.through the winter it was used everyday by multiple people for fun and pest control.at least 300 pumps a day,since the spring/summer time it hasnt been used to much a little pest control,some testing and sight in.still no issues
i like the set up its the only piston type i use now .it gets the same numbers as a flat top piston,lasts longer than o-rings and at a fraction of the cost
i think i paid $8-$10 and a new cup runs @$3-$5 installed
i do keep my guns/pistons well oiled.i should say airguns well oiled
Need to get me one of those pistons & a few cups,looks like a winning combination 1377x :)
My last seal deteriorated rapidly when my solid pin worked loose without me realising might put some thread lock either end.
I put some thread lock on my brass M4 nuts as same happens,they work loose....
i used a wrench to tighten my brass acorn nuts.they havent worked loose but did bend my tube slightly
i couldnt get my piston out until i spread the ends apart :o
I changed the acorn nuts for M4 brass full nuts,so could see threads and know when nut loosend off,also found some very thin brass washers for nuts to lock on to.
do they still loosen?
1377x, is that an old 760 piston you show in your picture?
I'm going to order one or six tomorrow if they are still available.
Carl
Quote from: quickster47 on September 20, 2011, 08:32:14 PM
1377x, is that an old 760 piston you show in your picture?
I'm going to order one or six tomorrow if they are still available.
Carl
sure is
760/140/130
the difference between the 760 and 130/140 is length of the steel part of the piston
Quote from: 1377x on September 20, 2011, 08:04:49 PM
do they still loosen?
little beggers stay put now :-*
Are these still available? If so, what are the part numbers? I tried looking at some old Crosman 130 parts diagrams and think I found what I need but there are several things on there that say "obsolete" or "order part ### instead"
Quote from: quickster47 on September 20, 2011, 08:32:14 PM
1377x, is that an old 760 piston you show in your picture?
I'm going to order one or six tomorrow if they are still available.
Carl
you know now that i think about it there is another style of 760 piston
its steel with the nowadays cup.i tried one them and it really needs to be adjustable to work in a 1377
Quote from: 1377x on September 21, 2011, 04:31:06 AM
you know now that i think about it there is another style of 760 piston
its steel with the nowadays cup.i tried one them and it really needs to be adjustable to work in a 1377
The original one was either plastic or Delrin or some other type of composite material and that is the one in your picture and the one I am after.
Carl
Quote from: quickster47 on September 21, 2011, 04:34:27 AM
The original one was either plastic or Delrin or some other type of composite material and that is the one in your picture and the one I am after.
Carl
yep
the ones in the pics above are the first oldstyle 760 piston.the 130/140 has the same style piston head
the other style piston is this one below.it takes the pump cup used now
(http://i613.photobucket.com/albums/tt211/edf73/P7300409.jpg)
Quote from: zoned on November 20, 2010, 12:10:20 AM
I think 90 durometer urethane may work well, Tim at Mac1 Airguns uses these for just about every kind of seal he puts in a gun. Those combined with some of his "Secret Sauce" should last for a long long time I would think.
Great O-rings! Hardcore last forever rings!
i think all the piston makers use 90 durometer orings these days!
i know ac and mellon do!
if (when) i go that route, i think i will plan on a cotter pin on one side, on a crown pin for easy breakdown..unless thats a bad idea.
(http://www.homedepot.com/catalog/productImages/300/b1/b10943d3-a3be-4de4-8f49-876fa9cc630d_300.jpg)
as long as it fits you should be good!
i was thinking of using something along those lines
That's not a bad idea. I think the reason behind using some of the other retention methods for the pin is the clean look. However, that being said, there is also something to be said for easier maintenance and disassembly. And using a crown pin will definitely lend itself to that.
Have you considered getting one of the aluminum barrel bands for your guns? They use a set screw to hold the pin. On my new 1377 I'm using one of Michael Chavka's barrel bands and for the first time I am using just the set screw to hold the pin. I did, however, mill a flat spot on the pin to give the set screw a flat surface.
His barrel band also has a set screw to hold the barrel. Something that the Bluefork Design barrel bands did not have.
Carl
maybe a spring loaded ball that snaps in place (kinda like m16/ ar15s ) it can be done. even flush.
when i tore both down i was able to keep the roll pin stuck in one side, w/out removing completely, and wondered if anyone had already designed better pins yet... (found em, but not quick release).
and maintenance is the name of the game
Quick, clean, and simple.
Did you make that brass pin? That is a great idea to use o-rings to hold it in place. Good idea. :-* :-* :-*
Carl
yes...that is simple.
the golden rule of "kiss"
not to go off topic too much
i like the mellon solid pin kit,put them in every pumper i get.the reinforcing ring makes a difference to me!
iirc he uses acorn nuts and flat nuts,if you ask he will probably make you one that uses orings
usually i take one nut off and push it through,pretty quick and easy.takes less than 10sec
Quote from: quickster47 on September 22, 2011, 12:12:00 AM
Did you make that brass pin? That is a great idea to use o-rings to hold it in place. Good idea. :-* :-* :-*
Carl
Yes. Got the idea from AC Custom Parts. Theirs cost $5 shipped and made of stainless steel.
Mine:
Hillman I#11518 3/16"-3' Brass round $3.07
Danco #60 O-Ring $2.27
TOTAL $5.34 +tax and a little time
P.S. I agree with 1377x about the mellon pin kit. Plan to get one and use my pin, also plan to order FT piston and have my valve FT.
Quote from: cmj21973 on September 22, 2011, 12:34:21 AM
Yes. Got the idea from AC Custom Parts. Theirs cost $5 shipped and made of stainless steel.
Mine:
Hillman I#11518 3/16"-3' Brass round $3.07
Danco #60 O-Ring $2.27
TOTAL $5.34 +tax and a little time
iirc didnt you make it with hand tools ???
Yep. Reply #4
http://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=4523.msg44667#msg44667 (http://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=4523.msg44667#msg44667)
Ah ha, now I remember all that drama. :)
Carl
Quote from: cmj21973 on September 22, 2011, 12:44:26 AM
Yep. Reply #4
http://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=4523.msg44667#msg44667 (http://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=4523.msg44667#msg44667)
Your brass solid pin is very nice. I have a cheaper version in steel (from an old nail).
I like the simple design of these pins with there being no thread to have the endnuts undo and fall off during a pump frenzy.
Here is my version, but hey the o-ring deal seems much easier!
Rich
I just received almost that exact same design from a guy from another forum.
I thought it up on a challenge,drew it up and he made it and shipped it to me.
Work's great!
Use a #6 socket cap screw.
What, and you only had one made? Might be a market for that you know.
Carl
I'll let him know!
Found a pic of it installed on my first build in June last year! Wow, has it been that long?? I really need to get my a55 in gear and finish off the next one! Another pic next to my failed two pc bolt handle!
For us tinkerer's this should be the very first mod on a 1377. Just makes life a whole lot easier going inside!!
Rich
Man that is one long bolt handle.
Carl
QuoteMan that is one long bolt handle.
I agree, and Rich, can you tell us about the "failed" part?
Cheers,
Jerry