761XL reseal help!

761XL reseal help!

Joined: January 8th, 2008, 5:12 am

September 2nd, 2011, 8:57 pm #1

Hello guys,

Could someone walk me through disassembly of my 761xl. I need to replace all the seals and i dont want to split this thing apart and stuff go flying. Another problem i would love to fix.... is there a mod for sealing up the breach and bolt? This gun as a ton of blow by I guess you would call it? I would think you could turn the bolt and o-ring it?
Back to resealing issue. I have found, through search engine, people claiming they have fixed there 760's with o-rings from the hardware store? What about seal/cup replacement, and the felt

Is the 760 and 761 internally the same?

If I could get some guidance on this I would surely appreciate it! Might even compensate?


Thanks.....Cliff


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Joined: February 25th, 2011, 10:27 pm

September 3rd, 2011, 7:38 am #2

I don't know much about the 761XL, only the newer 760s...

I always find it helpful to download the exploded parts view from the Crosman site... You can use it for reference... The main thing you have to look out for when disassembly is the hammer spring shooting out near the rear of the receiver... So don't pull it apart quickly, or even better yet, open it up in an old pillow case or put a towel over it if you're unsure... The second thing you probably have to worry about is the trigger spring shooting out or the spring causing the safety to shoot out... (Did it even have a safety?) These issues are usually universal in guns like these... It's also good to try and take a lot of pictures so you can reference them if you get stuck...

I've heard of people "turning" the bolt and putting a small "O" ring but I don't know the size or where to get them.... There was even a guy who tried making his own bolt but couldn't get the bend exactly right... You might even be able to get one of those little "O" rings out of a discarded disposable lighter...

The 760s from 1966-1977 seem to have similar internals... I don't know the exact differences between the two "Phases" within those years besides the wooden stock versus styrene...

Well, hope you get her sealed up nicely with no problems... Those old guns are pretty neat....
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Joined: November 14th, 2002, 6:27 pm

September 4th, 2011, 2:21 pm #3

Hello guys,

Could someone walk me through disassembly of my 761xl. I need to replace all the seals and i dont want to split this thing apart and stuff go flying. Another problem i would love to fix.... is there a mod for sealing up the breach and bolt? This gun as a ton of blow by I guess you would call it? I would think you could turn the bolt and o-ring it?
Back to resealing issue. I have found, through search engine, people claiming they have fixed there 760's with o-rings from the hardware store? What about seal/cup replacement, and the felt

Is the 760 and 761 internally the same?

If I could get some guidance on this I would surely appreciate it! Might even compensate?


Thanks.....Cliff


.
My cousin was the fastest guy on 760's I ever saw. He could do the 760/761XL in under 10 minutes each. We had pistons and valves already made up ready to put in so it was really fast.
Loosen the barrel support, drive the front pivot and remove the pump group.
Make sure the barrel is clear of projectals and close the bolt tight and remove the valve screw. Apply shop air to the tip of the barrel and blow the valve out the front of the tube. Be careful it is putting out some fpe. Best to have a punch in the crosshole.
Tap the front end of the tube on the work surface and the cap will slide out the guide. Toss a rebuilt valve, cap and piston in the gun and reinstall all the Hardware removed.
If the breech seal is blown the valve will not blow out the front. It helps to put the web of your hand in the cutout of the breech when you blowe the valve out.
If the back of the gun is all correct you do not have to take it apart to do a valve on a early 760, 1400 or 130 as long as the brech seal is tight. 1400 & 140 are a little trikier to do but they can also be done from the front.
If you are really carefull you can take the brass bolt of the 760 and peen down the tip to enlarge it so it seals better on the leade of the barrel.
Tightening the breech screw really good and tapping a little barrel material into the slot of the screw is how every Mac1 /McMurray and Son rebuild was done on all 760's so if you see that you know who did it. That is the signture for a Lloyd Treadwell/Timmie Max 760 or 761. In the 70's we did 1000's of 760 rebuilds.
There was a recall of the plastic forearm and we took all the inventory K-Mart had and installed wood in place of the deteriorating Plastic Gen I forearms. We did 1000 of those lever swap outs alone. Pellgunoil was making the open cell foam forearms crack at the mounting pins. Nightmare in plastic. R&D done wrong!

Crosman had a west coast Service Center Training course in Fresno one year and my cousin and I went. We raced side by side to see who could tear down and reassemble the 760 back end faster and Lloyd beat me by about 45 seconds. We were both under 3 minutes and everyone got a good laugh.

The Business model my Dad had was $15 rebuilds to $30 guns. It worked but you had to do a lot of $15 rebuilds.



"NO GUNS WOULD BE A RIOT"

Later

Tim

Mac1 Airgun


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Joined: August 16th, 2008, 3:22 pm

September 6th, 2011, 12:14 am #4

You guys did my 760 way back when!...nt.
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