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CPS bladder has hole or burst

Written by Ben
Last updated on 2008-01-22

Special thanks to forum member Ichabodv for the photos used in this repair guide.


Whenever you pump your CPS Super Soaker, water pours out of the inside of it. The problem is a burst CPS bladder.

This problem is becoming more common as CPS water guns age. The rubber wasn't made to last forever. This repair can also be done as a modification if you desire a power-up.


The solution in all cases is replacement. Naturally, bladders in some soakers may be easier to replace than others. In cylindrical chamber CPS water guns, replacement is easy. In spherical pressure chamber CPS, replacing the chamber will be more difficult due to the fact that spherical rubber bladders are not sold, but balloons can be substituted if a spherical chamber is designed. I have read about people using a cylindrical chamber in a gun that was previously spherical. In HydroPower (Water Warriors) water guns, replacement has not been done yet and no one knows how to replace at the moment, aside from swapping pressure chambers.

Some of you undoubtedly are thinking that a tire patch will solve this problem, but it won't. Unlike a bike tube, the CPS bladder has a wall thickness that is substantial, sometimes as large as a 1/4 inch. If the patch doesn't seal the rubber throughout the entire thickness, it's not going to work. And it would have to seal the thickness as well as the rubber did originally, which would be hard because bike tubes are made from different rubbers than the latex rubber of the CPS bladder, so the glues for those might not work optimally. Sliding a bike tube over the broken wouldn't work either because it has to seal. One on the inside won't work too. I've heard it all, and it doesn't work.

One shortcut you can do however is cut the bladder short of the hole is on one end of the bladder, which will save buying a replacement bladder. It also could increase water capacity a bit by letting the bladder expand a bit more. Read PC expansion for more information, especially if that seems counter-intuitive to you.

The tools you will need for this repair are screwdrivers, scissors, and a clamp.


Before you can start, you have to order some latex rubber tubing from McMaster-Carr. Order part numbers 5234K86 and 5234K92. You need two tubes because this can also be done as a power modification, and while you're here you might as well do that modification. If you don't want to do a power mod here, just order the first tube. Due to minimum lengths and shipping, you might have to spend $40 to get these tubes. However, you'll have enough remaining tubing to construct many more bladders.

This series of images shows how to get to the pressure chamber. First, open your water gun and locate the firing valve. Remove the screws holding the pressure chamber in (top right image). You can then pull the pressure chamber out to see if it has burst. The photo in the lower left corner is the worst this problem can get. Here the nearly entire chamber has burst. On your water gun, the burst could be small.

Open the other end of the pressure chamber case by cutting it off with a hacksaw. Later you can reattach it with duct tape. Remove the pressure chamber from the case and remove the clamp on the end.

Now take out your pieces of latex tubing. Cut them both with scissors to about the same length as the original pressure chamber.

Attach the back clamp to the new tubing. You might need to use a clamp to be able to close the tubing clamps over the rubber tubing. Then, slide the larger tubing over the smaller tube.

Attach the smaller tubing to the front barbed fitting and close the clamp over it.

Congratulations, you have replaced the pressure chamber! Enjoy your repaired water gun.


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