Friday, February 6, 2009

Smith and Wesson Model 79G Disassembly, Part 3

Almost done...

The piercing assembly.

Align the holes on the outer sleeve and punch out the roll pin.

All apart.

Small slotted nut on the inside.


It captures the small red o-ring that seals the piercing pin.

The valve is compressed by my thumb.

The o-ringed pipe that connects to the CO2 chamber is pulled out and the end of the valve pops free.

The valve assembly.

The exhaust valve stem is pressed out of the brass exhaust valve body

Finshing up with a pin punch.

The seal was easy to dig out. It's seen better days.

Next up? Resealing...


john said...

Thank you x100!

I recently inherited a 79G. Tried a cylinder and ssssss. Found your site and changed the cylinder screw main o-ring. Shot 30-40 rounds and sssss, an internal seal blew.

Followed your outline and replaced all the o-rings (except that one you made) and it's now tight as the day it was shipped!

Shot 30ish rounds dinking around with the power and sights, then ran 3 across the chrono.
478, 479, 474
Shot 20ish more and ran 3 more across the chrono
480, 478, 488
Shot 10 more...
490, 491, 488 ??
Shot 10 more!
489, 489, 489 (yes, 3 exact readings in a row!)
Shot 10 more!!
490, 470, 482

Tight as a drum and frugal as the best penny pincher.

Thanks again, john

Anonymous said...

Where can I buy the complete set of seals ?

Felice Luftschein said...

Unknown said...

Thank you! With your great instructions I was able to resurrect the 78G I got as a present back in 1970. It works like it is brand new.

Again, many thanks! Steve

PS any recommendations on how to refinish the slide to make it "purty"?

Nick Carter said...

Beadblast and give it some coats of a good quality paint. That's pretty much all you can do.

Ross B. said...

I took some 000 steel wool to mine and gave it a coat of flat black spray paint and it turned out to be a perfect match.

Anonymous said...

Can some one please tell me what part #11215 is? It's listed as the barrel valve connector. Is it an O ring? It mates the barrel to the valve body. Thanks very much in advance.

Anonymous said...

Can someone please tell me what part #11215 is? Is it an O ring? It connects/mates the barrel to the valve body. Thanks in advance. -- Tony

Tony said...

Can someone please tell me what part #11215 is? Is it an O ring? It connects/mates the barrel to the valve body. Thanks in advance. -- Tony

Unknown said...

I recently picked up a s&w 78g co2 pistol. 1st co2 cylinder...pssst...leaky valve body. Disassembled and replaced o-rings. upon reassembly 2nd co2 not leaking, but not firing. Any suggestions on how to SAFELY release co2?

derrick38 said...

Jeremy, I'd remove the upper "slide", and use a hammer and drift to tap the valve pin and release the CO2 from the valve.