Hacking Aquatec Pumps

Hacking Aquatec pumps

If you have been using meth for a few years you might have realized that the pumps lose their efficacy as time goes by. I've observed 2 of the areas that are culpable. You will need to disassemble the pump with a torx T20 socket.

1st and foremost, the regulator. If you disassemble the regulator you will notice it has a spring and a small cap that presses down on a rubber area in the pump head. This rubber can also be removed. IF you remove this you will notice 2 small holes. One is actually on the high pressure size of the chamber and the other on the inlet. It works by basically bleeding off from the high pressure to the inlet once it overcomes the spring tension. Over time this seal loses its efficacy and bleeds off much sooner than your desired target pressure no matter how much you adjust the Allen key screw. You may notice the holes have permanently marked/imprinted on the seal. You can flip/rotate the seal giving a the holes a fresh location on the rubber to seal with.

2nd culprit is the clear plastic that houses the EPDM valves. This is prone to cracking and also warping near the oval seal- leading to pressure seeping away from the high pressure side to the inlet area. This can be replaced for a few bucks (Devils own sells it) Also, the black housing that seals with the high pressure oval seal, is also prone to warping. A hot air gun can massage them both into shape but be careful they get mushy real fast, so use low heat even though it may take longer.

Having done the above fixes to your pump you should be back to a dead head pressure somewhere between 160 and 180 psi. By the way, none of the pumps i tested brand new gave me 200 psi for any longer than a few days! In fact, when I contacted Aquatec they themselves told me to ignore re-sellers claim of 300PSI as the regulator isn't designed to hold that much, let alone function at that pressure when spraying! I tested this myself and found it to be true. That is, a dead head pressure of say 200 psi results in about 160 psi while spraying. It won't function at 200 psi for any longer than a few days/weeks as the regulator's seal wears and start bleeding off pressure much sooner.

Ready for some REAL pressure?

I will show you how to get 200-300 psi dead head pressure and 160-200 spraying pressure. You remember the two holes on the regulator?

We won't be needing the inner hole one no more. This hole is on the high pressure side of the assembly and it is through this hole that fluid is bled off to regulate the pressure. I used a soldering iron and a clear tie strap to melt a nice plastic seal for that hole.

Results

The pump deadheaded 220 psi at 12 volts, and while spraying a 520cc nozzle it was at 185 psi. At least there is no more mysterious pressure drops to look out for :)