Zeke/PA
Member
Any suggestions as to why a Crosman MK I leaks when a CO 2 cylinder is installed?
cylinder leaks
- Thread starter Zeke/PA
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WestKentucky
Member
Most likely a bad o ring in it somewhere.
Zeke/PA
Member
I did replace two "o" rings in the grip area to no avail!
Johnny_B_Goode
member
You are supposed to pack silicone grease in the cylinder to prevent leaks. Walmart has grease sometimes. Most of the time I just order a couple tubes of grease from Crosman so I don't have to go to 45 Walmart's trying to find the grease.
Never heard of using silicone grease in a co2 pistol. Anyway, do a google search using "Todd Cooper Crosman Mark" and you will find a great article with all you ever want to know about these pistols. Resealing is relatively easy yourself. Plenty of places will do it for you or sell seal kits. Mac1 Airguns comes to mind.
You might try some NON detergent 30 wt. oil on the tip of the cartridge and the o-rings first to see if that stops the leak.
You might try some NON detergent 30 wt. oil on the tip of the cartridge and the o-rings first to see if that stops the leak.
Johnny_B_Goode
member
The reason you use silicone grease is oils make O-rings swell up. Once the O-rings swell up they become soft and fragile. You should never use oils on the rubber parts of any air gun. Oils are for the hinges and exterior of an air gun.
You have not read the owners manual of any air gun if you are pouring oil on O-rings.
Here is the proper oil for sealing CO2 cartridges. It is basically silicone grease but you need to see a tube of Pellgun oil before you can select grease from other applications.
http://www.pyramydair.com/s/a/Crosman_Pellgun_oil/222
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Zeke/PA
Member
Thanks Guys,
In truth, I didn't realize that oil/ grease was necessary on the CO2 cartridge.
I'll keep trying!
In truth, I didn't realize that oil/ grease was necessary on the CO2 cartridge.
I'll keep trying!
Get the crosman pelgun oil, it's what you want. Put a little drop on the tip of every cartridge.
Not sure what Johnny means by packing the cylinder, don't think you need that much of any lubricant....
Might have to do that rebuild though if your seals are already destroyed.
Not sure what Johnny means by packing the cylinder, don't think you need that much of any lubricant....
Might have to do that rebuild though if your seals are already destroyed.
beag_nut
Member
Wow.
So much wrong info. Silicone grease or oil is NOT to be used on silicone O-rings or seals. But the same oil/grease can be used on non-silicone seals. The reason is that the silicone in the oil/grease will be absorbed by the silicone seal and then swell in size. The problem is that it is difficult to tell the difference between a silicone seal and a non-silicone seal. Therefore the simplest and surest course of action is to not use silicone oil/grease on anything, unless one is absolutely SURE that no silicone seals are used in the mechanism. And it was critical that I knew this (and so did our company) when I made surgical equipment. Bottom line: use a quality non-silicone oil/grease on any seals, and use silicone oil/grease ONLY on seals which are known to be NON silicone.
To add to what was said about silicone grease---it is generally accepted that NON-detergent 20 or 30wt oil is ok to use on co2 air gun seals and O-rings, just not in huge amounts.
I just fixed this problem in my Crosman Mk1. Check out this website http://www.mac1airgunshop.com/default.asp. You can buy the seals and valve stem repair kit that you need. Very high quality o-rings, much better than the first that I bought from ebay.
It is also possible to get a service manual on line with some searching as a free download, but I can't remember the site.
It is also possible to get a service manual on line with some searching as a free download, but I can't remember the site.
Agree, good grief, please don't pack your gun with grease.
A drop off pellgun oil on each cartridge, or every other cartridge will take care of any kind of lube the gun needs.
Most people think that pellgun oil is a synthetic oil with a high flash point. Crosman suggests it for all their CO2 guns and on the pump head of all their MSP guns.
RWS sells stuff called chamber lube...gamo sells lube...they all do and they do so for a reason.
Really any synthetic oil can be used in an air rifle, stay away from dino based oils.
At one time they even put stickers on the guns.
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