Air Gun Home :: View topic - crosman 1077 leaking CO2 as soon as cartrige inserted

wichone49 · New Member

You have probably answered this 100;s of times, but I thought I'd run it by anyways.

Many years ago I bought a used Crosman 1077 and gave it to my father to shot a varmits (mice and rats) getting into his chicken feed. Dad passed away almost six years ago and earlier this year I picked it up from my Mom. Anyways just now tried to use it, inserted new CO2 cartridge and worked fine. Set it in the corner and left, but wife said it started hissing (she thought it was going to explode). Got it and no pressure left, so inserted a new cartridge. Gas escaped immediately from around the housing and around the trigger assembly as soon as I screwed the cap in to pierce the cartride. Looks like a seal failed, my question is where is the most likely one to go and can this assembly be repaired withot tearing down the whole rifle? Thanks for any information.

AirGunEric · Site Admin

You need to tear down the hold rifle to do it. Some people have tried (and maybe succeeded) in replacing the Co2 caplet seal using a really long screwdriver of the exact width of the seal cap- but as this is already leaking, the gun is well over 5 years old, you would be well-served in replacing all the seals at the same time.

wichone49 · New Member

Thanks for the quick reply. I think you gave the best advise, replace all seals, but I'm not good with small parts. Probably the rifle needs a bit of oil on the parts too, probably just use my Zebco or Garcia reel lubricants. I liked the tip on placing an assembly in a plastic bag to keep from scattering small parts when pulling apart. This never dawned on me, a useful tidbit of information. I still do repair and clean my own fishing reels so hope this will help when I do this. I really hate it when I drop a small screw or washer and have to get down on the floor crawling around on my hands and knees looking for it... but a magnet seems to help sometimes...except if they are stainless. Have a great day.

RichFet · New Member

I have a Crosman 1077 and it appears to leak from the area where the CO2 cartridge is pierced. I have several new parts but after pulling the roll pin 1077-031 and unscrewing 338-041 the piece holding the parts into the brass 1077-A018... Not sure how to remove the other pieces 38-128, 38-A027 & 38-128 without totally destroying everything. A video of removing these would be most helpful.

AirGunEric · Site Admin

No video, look here: http://www.airgunhome.com/pages/1077disassembly.html

The being said, if you have the Co2 piercing block removed from the tube- unscrew the retainer (will be either black or brass colored) to remove the seal, filter screen (which may or may not be present) and piercing pin.

RichFet · New Member

Thank youfor the reply. The link was helpful - my son had found it earlier but thank you.
Once I posted, I took the 1077 apart again and then use my compressor and blew backwards to get the 3 pieces out. The screen was damaged by this action. The 38-128 old part seemed to be very much bent out of shape compaired to the new part.
I now have the entire unit back together but... there is hissing that now seems to be coming from the 1077-015 area but I can not tell easily when the gun is put together - I hear it (with a new cartridge) when I have the magazine out and listen there and also when I listen above the trigger guard area... so I only think it is coming from 1077-015 area.

I wasted a 12 size cartridge by using it while having the side off of the gun but was unable to determine where the leak was coming from. -- The brass tube blew off of the 1077-A018 while I was listening close to the unit trying to find the source of the leak - at that point my hearing was shot for a while and the rest of the cartridge leaked out while I tried to drip soapy water on other areas looking for bubbles.

I was able to put the gun together and site the scope in with my son's help using two more 12g cartridges and about 36 pellets. The cartridge loses power in about 2 minutes and 25 shots depending on how fast we get the next dozen into / through the gun.

How can I determine the location of the leak? I have rebuilt / replaced about 5 or 6 of the seals (the hardest being the 38-128).

Should I get another set of seals and try it again? Really don't want to waste more cartridges.

Also... is there a way can hook up compressed air to this unit (I also have the crossman airsource adaptor (that my son accidentally emptied the only canister when he played with the box of stuff about 2 years ago).

AirGunEric · Site Admin

If you have the AirSource adapter- get some more AirSource cartridges. Compressed air is an altogether different issue, and perhaps one to be addressed when you solve your leaking issue.

As for 1077-015, the valve body- the seals inside should be replaced and the seal on the tube input slot (o-ring/quad seal) should also be replaced. Do not lube the quad seal beyond getting it a bit pliable- oil on them tends to cause leaking if the oil is put on prior to assembling everything completely.

RichFet · New Member

Thank you,
I have replace the following parts and there still seems to be a leak but i can not seem to track it down. It is a very slight hiss but obviously is causing the gun to lose pressure fast.
How can I find the leak or at least narrow it down so I can figure out what to go after? Plumbers use soap and water spray to find leaks - your thoughts? Anyone ever clamp a few things in place while inspecting an open gun under pressure for leaks - if so what should I watch out for and then what should I use for locating the leak?

Taking apart and putting together is a piece of cake after you have done it a dozen times in a day.

On Valve 1077a015 Replaced:
O-ring on 106A036
357a054
1077053
1077052

On the cartridge receive brass 1077018 replaced:
357a054
38-128

Anything more that you'd suggest to replace?

jkjunkie · New Member

Ever get it working? I have the same problem. I think the 130-032 seal at the C02 chamber is leaking on mine.

RichFet · New Member

I never ever got it working --- I gave up. I tried to install a kit that uses larger CO 2 canisters and it just leaked all of those out in a minute or two so... this is a bad gun and I just don't use it at all. I am thinking to throw it away - not sure if the company can fix it either. This gun has been a POS since I bought it new. I'd never recommend this Air Rifle to anyone and might consider telling people to stay away from anything from this company.

ZipSnipe · Veteran Member

Ya know the 1077 is not the best designed gun but it is fixable. Just need lots of patience.

When working on anything always set up a workspace before even touching the gun. This is critical as there are small pieces and easy to lose if you don't set up a work space. Kitchen table with a big white or light colored towel underneath is perfect.

So if you do decide to tackle such a project, replace all seals while you got the gun apart, I looked for burrs when doing mine, burrs are edges along the parts that have not been smoothed out, some light filing and this gun can be made into a usable fun gun.

Coyotehunter_ · New Member

Hi,

I'm new to this forum. I came here to find out someone else but ran into this thread first. I thought I'd say something as I have two of these Crossman 1077 Air Rifles and both of them are junk now due to the leaks you are talking about.

I took my two Crossman 1077 Air Rifles to the local Crossman Authorized Repair shop to get them looked at and to be appraised. The man who actually owns the shop and who's been in business since I was a teen ager 40 years ago told me to just junk them both. He said it would cost more to fix the leak than to just buy a new one.

Well the second Crossman 1077 was bought because I could not get the older one to work with the Crossman 1077 Upgrade Kit.

When they work they are fun guns to shoot and pretty precise with a brand new full CO2 cartridge. I put a little 4x rifle scope on mine and used it to shoot pests like Fox Squirrels and English Starlings that raid my bird feeders. I love the rotary clip design and the looks of the gun but it's useless to me if it won't stop leaking all the CO2 out.

I read where if one used the Crossman Oil on the Seals that helps but it won't help if the seals are already leaking. It's probably that the seal ring is cracked.

I worked in the field of Air Sampling and understand how hard it is to get a seal that won't leak air even a little bit. I mean I use to measure air leaks by pulling a vacuum on a system and then hooking a water manometer measure the vacuum in the system and to see how it changed over time.

I also used a very sensitive rotometer to measure small air flows of around 2 or 3 ml/min rate. Hook up the long narrow sensitive rotometer and then tilt it on it's side at about 5 deg up angle and see if the tiny ball moves due to any air flow. I plugged the system off with a Swageloc type cap and then looked to see if there was air moving though the system when it was charged with an air source. I use compressed nitrogen gas to purge the system and check for leaks with a solution of Leak Check that bubbles at the point (source) of the leak and that was non toxic and did not leave any residue on the equipment.

The machines I was working on cost ten's of thousands of dollars and were used to read air pollution levels for the 3rd largest city in the State of IN. So it was a big deal to make them work right all the time.

So I've already tried to fix the problem by buying another Crosman 1077 Air Rifle and it didn't last me longer than a couple of years.

I won't buy anymore Crossman 1077's due to the leaking problems and the cost of repairing them if you go that route. Now with that said if you can repair them yourself and buy the parts cheaper than buying a new air rifle then go for it. Good luck though.

I went out and purchased a new Gamo IGT air rifle and have been using it for a year or so now. Other than getting the Gamo 4X scope to stay put its' been a pretty good air rifle. But it's a single shot and shoots the light weight allow pellets at a stated 1300 fps. It's loud too, even though it claims to have a special silencer type barrel on it. It's as loud at a 22 short rim fire rifle IMHO. The pellets will break the speed barrier.

But I came here after doing a Google search for pellet drop on air guns. I have a bunch of pesky Starlings that are raiding my bird feeder and are flying away when I get the Air Gun out. They land in the 25 year old maple trees about 40 yards from my back kitchen window where I'm trying to shoot them.

So I have to figure out the bullet path.. drop... to figure how low to aim when shooting up at 45 deg with this Gamo Air Rifle.

I aimed at a spot in the tree about 40 ft. up in the air and about 40 yards away in a straight line and hit high about 6 " and over to the left. Now I understand why I'm hitting higher as I zeroed the scope at about 30 to 40 yards away and was shooting at a target that was level with my shooting stand.

So all I want to do is get a few of these starlings knocked out of the maple trees to make the other's stay out of my bird feeders.

All birds are welcome to my feeders except these big flocks of these stupid starlings. Smile

I need a way to discourage them form my bird feeders.

I took care fo the squirrels with a HavaHeart Big Live animal trap and then transported them out of the neighborhood. But these birds are too light weight to trip the trap door on the cage. It's made for Raccoons and squirrels not light weight birds like Starlings. So the pellet gun is my last and only option that I can think of right now.

I had a Daisy CO2 Pistol that also had problems with CO2 leaking.

And a Crosman 357 Pistol that had the hammer break on it. I gave it to one of the neighbor kids 12 year old to see if his dad could fix it for him.

Several of the pellet pistols that I owned had the needle tip that breaks the seal on the CO2 cartridge break off. This rendered the CO2 gun useless.

I have one pellet pistol that I really like a lot. It's holding up good after about 4 year now. It's got a 8 shot rotating metal clip that fits inside the pistol. It's a Walter CPS Sport Pistol. I love this little pistol. It's reliable I guess is the word. Now once in a month I have to check the CO2 cartridge and it's possible that it may last two months before it's low on power. But it's a lot better than any of the other CO2 pellet guns that I've owned.

I also have a `Crosman American Classic Model 1377 in 0.177 Caliber. I's a pump type pistol that also can be converted into a short rifle type pellet gun with an additional stock that's added to it. I like this single shot gun too as it's reliable.

I just wish that they would make the rotating clip type air pistols and rifles with a more reliable seal for the CO2 cartridge connection with the gun.

AirGunEric · Site Admin

Coyotehunter_ · New Member

It's a kit that lets you use a larger CO2 Cartridge instead. It's has a metal piece that screws onto the hollow tube where you insert the CO2 smaller cartridge and then has a long metal pipe that fits deep into the hollow tube on the air rifle to seat next to the seal on the air rifle.

I think that the cartridges are 88 Grams in size. The pipe that fits into the air rifle where the CO2 plug goes is about 7.5" long and about 1/2" in Outside Diameter

The cartridge is connected to the pipe by a bigger Value System that's about 4" long and 1" in diameter. The CO2 cartride sits parallel to this pipe and about 2" below it (center to center) So when you insert the upgrade kit into the air rile the bigger CO2 cartridge is sitting below the barrel and about 1/2" it. IE there is about a 1/2 to 1" gap between the two.

It's Crosman part number: 1077AD-520

You should be able to see it on their web page. Not sure if it's still there as it's been a few years since I was last there and bought this 1077 Upgrade Kit.

The 1077 Upgrade Kit is great but the seal on the Crosman 1077 CO2 Pellet Rifle where the pipe seals the CO2 connection is shot on both my Crosman 1077 air rifles.

Oh yea the first 1077 that I bought was not made to work with the upgrade kit which is why I bought the second 1077 air rifle so that it would work with the 1077 upgrade kit adaptor that I bought for the first air rifle. I didn't know that it would not work with the first air rifle as it was manufactured before a certain date. Only the Crosman 1077's which were made after a certain date are suppose to work with the 1077 upgrade kit.

AirGunEric · Site Admin

Ah, ok, that kit is normally referred to as an "AirSource kit"- as it allows the use of AirSource 88g canisters.