Disclaimer: The following repair guide is provided for informational purposes. Not all these repairs have actually been tested here. iSoaker.com and its affiliates cannot and will not take any responsibility to any damages caused as a direct or indirect result of anything attempted. Use at your own risk/discretion.
The following listing is of common problems found with various water weaponry and some suggestions on things to look for in order to fix the problem:
Blaster will not accept any more waterMake sure that the reservoir is not already full or filled with something else. If one is having trouble filling up one's blaster from a small faucet or tap, try using a cup or glass to bring the water from the sink to one's blaster (it may take a little longer to fill, but it will let one fill the blaster properly in some cases)
Pumping is difficult/impossibleIf the pump cannot be pushed or pulled (if applicable), its innards may have dried out and crusted. Try filling the reservoir with water and pulling/pushing harder on the pump. If it breaks, the blaster was useless anyhow.
If pumping is merely difficult, addition of some form of lubricant (i.e. Vaseline) to the pump shaft may help alleviate this problem.
Opting to open the weapon for a pumping problem usually does not help as the pump's shaft is typically sealed inside.
Pumping does not pressurize the blaster/firing chamberMake sure there is still enough water in the reservoir and that the blaster is in a proper position to allow water to be drawn into the pump. If using a pressurized reservoir weapon, ensure the reservoir or reservoir cap is securely attached to prevent air/water escaping from where it should not.
Blaster will not shootMake sure there is water in the reservoir and the firing chamber (if applicable). Try pulling the trigger harder if pumping appears to be pressurizing the firing chamber.
Check the nozzle to make sure it is free of debris. If there is debris, attempt to clear the blockage by using a long needle/wire but be careful not the damage the nozzles or any of the blaster's inner-workings.
If using a blaster with multiple nozzle settings, ensure that the nozzle selector is properly aligned to the nozzle of choice and not inbetween settings.
Blaster shoots mistOn some models, ensure the blaster is in an upright/horizontal position such that the output tubes are immersed in water. For CPS-based weapons, make sure there is enough water in the reservoir, pump up the firing chamber with a few strokes, and try firing again