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Airtech 4000 pump replacment

Super solid and super easy!

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#1 Just582



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Posted 08 December 2013 - 01:03 AM

The At4k is a pretty amazing blaster, with a huge air tank and twelve dart capacity (Soon to be 36! coming in February!) But like the 3k, the 4k has a large diameter pump, preventing you from getting high pressures easily. I will show you what I believe is the best method for doing a pump replacement. Magstrike pumps are pretty great, and I didn't have any other suitable pumps for a pump replacement. This is a strong, clean, and stupidly simple way to replace the pump on a at4k.

Materials list:
Magstrike pump
airtech 4000 pump tube
Small stub of 1/2" cpvc
1/2" cpvc coupler

Tools list:
hand drill or drill press
Tubing cutters (The kind for cutting brass tubes and stuff)
Scrollsaw (Hacksaw or similar should work)
1/2" and 1" spade bit
Wire cutters
Rotary tool
Stone Grinding/sharpening bit

The first thing you need to do is take the stock pump out and unscrew the weird little nuts and the tubing. Next, take your 1/2" spade bit and drill off the original tubing connections by putting the tip of the bit in the air output of the pump. It should look like this:

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Then take your 1" spade bit and put it where the pump should be. It should be a slighlty tight fit, and drill until its very loose by drilling normally then rotating the pump tube slightly, and make sure you don't damage the the orange plastic. Don't really know how to explain those last parts very well.

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Clean out the leftover bits of plastic with a long screwdriver and some water. The 4k's stock pump is finished for now.

As for the magstrike pump, use wire cutters to break of part of the tubing connection. Don't use pliers, I tried that first and broke off the entire connection. Should now accept 1/8" x 1/4" tubing and look like this:

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Sand this area using a dremel with the grinding bit.

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Magstrike pump should fit pretty tightly inside the 4k pump now.

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Now push the magstrike pump in just the right distance and make a mark so that the top of the magstrike's pump cap is flush with the wall of the 4k shell shown. Also make sure the ridge at the bottom of the pump cap is even with the other wall shown. Make a mark there.
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Remove the magstrike pump from the 4k pump tube for now.

Now that the 4k and magstrike pumps are done, put your stub of cpvc in the coupler and cut it even.

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Put the side of the coupler with cpvc in it over the air output of the magstrike pump.

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Now put the magstrike pump in the 4k pump as far as it will go and make another mark next to the first mark.

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Cut down the coupler as much as the distance between the two marks. Mine ended up being flush with the top of the magstrike's tube connection. Use the tubing cutters to score the coupler, and the wrench to help turn it, then cut it with the scrollsaw.

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Now put the magtrike pump back inside the 4k pump tube as far as it will go. The pump should be in the same place is was when the first mark was made.

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I don't have any pics of this, but use the dremel and grinding bit to make the magstrike pump rod and pump cap fit. Put epoxy putty in the back of shell where the 4k pump rests and at the pump cap. put some grease on the pump cap and back of the 4k pump so the epoxy putty only sticks to the shell but not the pump parts. I will try to add pics of that tomorrow.

Edit: pics are now fixed

Edited by Just582, 08 December 2013 - 04:54 PM.

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#2 sublimedom777



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Posted 08 December 2013 - 02:06 AM

I feel like a bad person for sitting on this information for so long, But since I started working on my AT4Play forever ago, I noticed that the 4k trigger has an ID that is prety much bang-on equal to that of the OD of a 3/4" CPVC coupler. If you dremel out the ridge inside, as luck would have it, the ID of said coupler is VERY nice sliding fit around a MS or Hornet pump tube. Please use this to your advantage in the future, folks!
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#3 CoolpantsMcgee



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Posted 08 December 2013 - 02:10 AM

Use [IMG] links. It helps, a lot.
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