SC500 repair

[soakinader]

*I completely forgot to mention, the internet ate my first post. This is a MK2, which states "Constant Pressure" on the sticker, not Air!

I recently acquired a Super Charger 500 that has some issues. When pumping, after a few pumps, water starts bursting out around the pump. The chamber only holds enough water for about one and a half seconds of shot time. Something is clearly wrong here. Even when I tried filling it with my homemade QFD (writeup to come) I ended up with water spraying everywhere after less than a second, and the reservoir didn't get any water at all. Something is clearly not right.
After cutting at it for nearly half an hour, and breaking an entire exacto blade into seven pieces, I managed to open it. Pics to come.What follows is my own speculation. Try and write out your own ideas on this before reading mine, I want to get as many different ideas on this as possible.

The internals are not too impressive, for some reason they used a non-stainless spring to support the tubing, which rusted like crazy and made a bit of a mess on the internals. That, however, is not the problem.
The pressure chamber is not only easily removeable but also easy to open, except the rubber chamber itself is stuck inside of the plastic casing, and no amount of pulling will get it out. I could try and remove the rubber chamber, but I don't know how I could "Anti-K-Mod" it. Maybe if I stretch the rubber somehow?

The pump has a terrific seal. No matter how tight a different pump is, it still won't work.
It appears to use a type B valve, but I can't disable the PRV, because not only would that defeat the purpose of it being a Super Charger, that may
not solve the problem either.

marauder_4 from Hydrowar (http://punkrockcowboy.brinkster.net/sc500.html) appears to have a MKI with the same problem, except that he doesn't say whether the PRV works properly, putting water into the reservoir, or not.

I figure this might have something to do with the one-way valve which is supposed to let water from the pump into the reservoir. If, the chamber is unable to expand, and that valve is stuck shut, that would explain my problem. Fact is, I don't know. Anyone have a problem like this before?

[marauder]

Soakinader, can you post pictures? I am really eager to see if we can find a solution to this problem, as you mentioned, I encountered the same problem. I didn't have time to mess with it, so I just sold it to GJIV lol. He may have some valuable input, but I'm not sure if he was able to fix it. I don't remember if my PRV kicked in after only 1.5 seconds worth of shot time, what was up with the PRV. I didn't have time to examine it like I said.

Everyone I've talked to with an mk1 (3 people) had the same problem. Some old sites used to list it as "air pressure" which is completely incorrect - but every mk1 I've ever heard of has been underpowered. I love the size/feel of the 500. It's a real shame.

[soakinader]

Here are the pictures, as requested. In approximately 12 hours, I will take the hard chamber outside, and attempt to fill it with my QFD. Either it will blow up or it will explode. XD Here's hoping it blows up/fills up, and then hurls the water back out. If anyone has any qualms with that, let me know.
All current photos here:
Overall picture:

(The pump cap is in a bag with the screws between the two halves of the shell)
Oh crap I just realized that I have not taken a single picture of it yet with the sticker side... but I assure you it is a MKII.

[Andrew]

Do you know exactly where the water is leaking from? Is water coming out through the pump tube around the pump seal? If the pressure isn't enough to open the PRV and fill the reservoir,then the problem probably isn't with the bladder. Does it leak through the pump when you QFD fill it? Water shouldn't be getting anywhere near the pump when QFD filling it. That would suggest something wrong with the pump check valves rather than the PRV or bladder.

[soakinader]

The water is leaking out from around the pump, from the pump tube. Basically water is drawn into the pump, and then it refuses to go anywhere once there is a small amount of water in the PC. If the QFD is used, the water doesn't leak around the pump, it fills the chamber a tiny bit and then it becomes impossible to hold against the QFD. I imagine the PRV is the culprit, but what doesn't make sense, is if the PRV is frozen shut, then shouldn't I be able to pump the chamber up until it is ready to burst? The water just bursts around the pump head; adding tape or using a tighter pump head just makes it rock-hard to pump, but if you try, the water will still burst out. So which valve would shut after the PC was normally filled 100%, and can I weaken it so that I can fill all the way? I am going to go and try the PC right now. Rubber has resistance issues, valves rarely do, although there was this Vaporizer I fixed once with a stiff shooting valve. You would pump and at the very end of it, you would get a short burst of water, unlike normal vaporizers which just shoot the whole stroke. Cut it open, replaced the spring, and once glued back together, it worked better (but lost some range if you didn't pump a bit quicker than normal). Here's hoping the 20% capacity issue is fixed!

[soakinader]

I have just finished re-testing it, now the rubber chamber has decided it likes to expand when I use the QFD, (I made sure of that) but it still A: refuses to fill the reservoir, and B: can't be pumped from empty more than 3 times before it stops filling the chamber, and starts leaking around the pump. I think I will re-assemble it and try QFD filling a few more times, maybe the hose pressure will be enough to finally open the PRV. Only thing is, I still can't pump much water into the chamber....
So, to recap:
MKII SC500
QFD fill: ~4 seconds of shot time, no reservoir filling
Pumps to "max":3
Normal shot time: ~1 second

[soakinader]

Finally, after intense QFD therapy, I have managed to get the SC 500 to work properly! Yay!
I tried pumping it with water, air, fast, slow, and I got nowhere. But through the magic of the QFD, I was able to breathe life back into this old piece.
When I first tried to fill it with the QFD, it seemed to get me nowhere. But after opening it and filling the chamber directly (and that was crazy!), then closing it back up and shoving it into the QFD for almost 20 seconds, I finally heard the hiss of the PRV open and the reservoir started to fill. Shot time: about 4-5 seconds of max range (pretty impressive range, it seemed) and another second or two of water dropping off, it seems to work great. Afterwords, I found that I could (finally) fill it by pumping hard and fast.
Problem is, water still leaks around the pump, but at least now I can fill the PC to max. Only thing is, with the water leaking around the pump, I only get to fill the chamber twice on a full reservoir, and then a few pumps more. I will try and get some tape under the pump head, and see if I can stop the leaking. If anyone has any recommendations for pump seal improvement, let me know. The pump is stiff already, so I will add some silicon grease too.

While I don't know if I even had to open the SC500 completely to fix it, I am glad I did, in a way. It still looks great, and now isoaker can have my internals' pictures!

So I leave you with this: Try QFD therapy. It takes patience, it takes strength, and you will probably get sprayed in the face a few times. But it might be the miracle cure for other SC blasters out there!
Soak on! 'Nade your enemies!

[soakinader]

Pump problem fixed!
I noticed that the tip of the pump head was narrower than the back. So, I shoved in a piece of 1/2" tubing left over from a solar shower, cut it down to size, and added some silicon grease. Done. Now it works great!


Also, I took a little bit of cyanoacryllate glue and fixed the sticker. I am going to have to try that on my CPS 1000!


Now I have a perfect little soaker. I think I still would much rather use an SC600, but this is such a nice little gun, I am sure it will have it's uses as a secondary.
I think I will call this one "Super Charg" for a while. Charg charg charg. Charg!

[Andrew]

So it was a sticky PRV and a poor pump seal. I've had a similar issue with my XP70's pump, and pushed a balloon ring (that little thing at the neck of a balloon) underneath. That makes sense as I couldn't understand why the pump would leak when using the QFD.

The PRV must have been seized with age and lack of use (luckily you didn't damage any of the components by over-pressurising them).

Glad to hear it works now!

[marauder]

This is the same problem I had with my mk1. I wonder if there really is any difference between mk1s and mk2s. We know that mk1 is CPS and not air pressure like the sticker says. I'm going to have to get another 500 now and try it out.