Crosman 760 Repair

**Quaker** · December 8th, 2009, 07:06 PM

"You're going to shoot your eye out"

As kids with BB guns, we've all heard that, a memory we all hold dear.

Forth years later though, that BB gun isn't working so well. I have a Crosman 760 that fires and then does'nt. Trigger won't even pull. For $40 dollars a new one could be purchased, but that wouldn't be right.

How can I fix it without having to spend more money than it is worth?

**CPratt** · December 8th, 2009, 07:33 PM

Years ago I worked at a machine shop that made Dart rifles. Crossman made one of the rifles I frequently serviced. One of the biggest problems was when it was pumped up it would not hold air. We had a tool made by Crossman to remove the piston/seals and i don't know if you can get them out without the tool.

**Quaker** · December 8th, 2009, 08:01 PM

Additional pumps don't appear to increase pressure. When new, and a little kid, pumps after three were difficult. It now seems that any additional pumps are no more difficult than the first.

A post on another site responding to someone else's problem, suggested that the "o" rings had become dry. Poster suggested oiling them. Didn't describe how to get at them though.

The dry problem makes sense though. If they contracted as they dried, this would explain why no more air pressure is built or held. Forty years in the closet could do this.

Why it won't fire, I don't know.

**Azzy** · December 9th, 2009, 02:30 PM

Not too familiar, can you post a picture? Ive worked on Brass Eagle (original CA manufacture, not modern trash) paintball guns which used the same system as the Crosman air guns. (Most modern non electronic use a Sheridan style poppet valve)

The valve can usually be removed with a wide blade screwdriver, that you need to cut a notch in for the valve stem. You should be able to get a rebuild kit from crosman, just may have to get a parts list from them and figure out what parts you need yourself. Or head to the hardware store, buna-n rings should work fine for the application.

If you find lead seals in there, I wouldnt be suprised, and at least in Sheridan rifles, you can leave them out without a problem.

**Quaker** · December 9th, 2009, 03:37 PM

On the same level of plugging and replugging in, I rotated the ring with my finger and oiled it.

Seems to be working better now, althought still not with same power as remembering as a kid.

**Azzy** · December 9th, 2009, 05:36 PM

Time does seem to add size, distance and general awe to our memories

I would think a typical pump pistol from Crosman should be able to kick out 200-300 fps with a normal amount of pumps. Dont forget, if you over pump (at least on the Sheridans) you can actually damage the seals and cause lower velocity.

When was the last time that barrel was cleaned and lubed too?

**Quaker** · December 9th, 2009, 05:40 PM

You can clean and lube a barrel????????

I definately believe the problem is within the pump cylinder and the ring. It doesn't always fire, but turning the ring with the thumb will enable it.

Since I am not working I won't be spending a dime on it and will just have to live with it.