S&W 79G rebuild question

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Pale_Rider

Pale_Rider

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Feb 16, 2019
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Just bought this 79G. Seller claimed it’s been sitting in storage a while so it will most likely need to be rebuilt.

1565916280_17837117345d55fc78ae6325.06067969_F6E19323-0270-4A12-8A14-357218C8999D.jpeg


The two most reputable companies selling rebuild kits are: 

1) Baker Airguns

https://www.bakerairguns.com/product/smith-wesson-78g-and-79g-seal-kits/

2) MAC 1 airguns

http://www.mac1airgunshop.com/mobile/Product.aspx?id=38030



Anyone have experience with these kits or another kit?








 
if you find a parts diagam

part number 11047 uses a #012 o-ring

11041 uses a #006 o-ring 

11226 uses a #113 o-ring

they should be urethane o-ring but then you have the seal on the valve pin to deal with

I have cut mine with leather punches and the pin is 2 pieces and needs to be pressed apart and together so, been using 1/8 urethane sheet goods for the seal

the pistol come apart alright but part 11251 holds the front of the pistol together and they don't just fall out, you need to use a drill bit in your hand to catch the tube and pull out or a easyout

the piercing cap come apart but you will need to make a notched screwdriver and the 4 side screw have round slots that you can screw up very easily

there are other tricks like pushing on the back of the valve to pull out part 11213

https://www.dropbox.com/s/h7bw4puo5f7m7vf/SW_78G_79G.pdf

why urethane material for a co2 pistol, it doesn't absorb co2 and swell 

the seal kits are on Ebay also material unknown

so with all the bits and pieces they are an easy pistol to repair and I hope some of this info is helpful

take care

mike


 
Upvote 0
if you find a parts diagam

part number 11047 uses a #012 o-ring

11041 uses a #006 o-ring 

11226 uses a #113 o-ring

they should be urethane o-ring but then you have the seal on the valve pin to deal with

I have cut mine with leather punches and the pin is 2 pieces and needs to be pressed apart and together so, been using 1/8 urethane sheet goods for the seal

the pistol come apart alright but part 11251 holds the front of the pistol together and they don't just fall out, you need to use a drill bit in your hand to catch the tube and pull out or a easyout

the piercing cap come apart but you will need to make a notched screwdriver and the 4 side screw have round slots that you can screw up very easily

there are other tricks like pushing on the back of the valve to pull out part 11213

https://www.dropbox.com/s/h7bw4puo5f7m7vf/SW_78G_79G.pdf

why urethane material for a co2 pistol, it doesn't absorb co2 and swell 

the seal kits are on Ebay also material unknown

so with all the bits and pieces they are an easy pistol to repair and I hope some of this info is helpful

take care

mike

Click to expand...

Thanks for the detailed info mike. I will definitely order some parts off eBay but still ordered the MAC 1 kit with the custom looking poppet. I don’t have the equipment/skills to make poppets 
 
Upvote 0
I re-sealed a 45 yo 79G a few months ago using an Ebay kit. The only thing that really needed replacing was the large seal on the piercing cap. The poppet valve was in good shape and still seals after about 50 Co2 cartridges. Initially, I got about 65 shots per cartridge. I have since added a #61 o-ring to the transfer port resulting in about 85 shots per cartridge. (two turns on the stock hammer spring the whole time). The green electrical tape is used as shims between the frame & valve. The plastic shim (.015") elevates the barrel in order to provide better alignment with the loading port and and allow the "snugging" of the barrel screw.

1566095787_4832109905d58b9ab03c679.17717202_IMG_20190720_161505.jpg

 
Upvote 0
Boscoebrea, does your SW 7XG hold pressure for a few days? Weeks? I ask because the first time I re-sealed mine I noticed that the transfer port didn't have a rubber/polymer seal, but didn't think much about it then. As described above I added an o-ring and shot count went up due to plugging a leak downstream from the valve. Also, post seal installation it was mentioned to place a piece of tissue paper over the breach area and fire the pistol to indicate a leak at the transfer port. 

Roboslug


 
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