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.
airtech 4000 pump tube
Small stub of 1/2" cpvc
1/2" cpvc coupler
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
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:
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.
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:
Sand this area using a dremel with the grinding bit.
Magstrike pump should fit pretty tightly inside the 4k pump now.
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.
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.
Put the side of the coupler with cpvc in it over the air output of the magstrike pump.
Now put the magstrike pump in the 4k pump as far as it will go and make another mark next to the first mark.
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.
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.
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
Just582Member Since 03 Aug 2013
Offline Last Active Private
- Group Members
- Active Posts 50
- Profile Views 3,644
- Member Title Member
- Age Age Unknown
- Birthday Birthday Unknown