XP 70 firing valve seal repair

[Fishfan]

I'm getting sick of the firing valve leak in my XP 70. When I pump it up fully, it leaks profusely from the firing pin. I have decided to repair it. However, I have no experience when it comes to take a saw to a soaker/soaker part. Does anyone know how to repair a leaking firing valve? My guess is that some kind of washer has gotten old and cracked.
Pics of the firing valve:




I couldn't find my mom's camera so I had to take it with my webcam.

[marauder]

It is highly likely that the spring inside your firing valve is old and rusted out. It's very easy to replace. Just saw open the back end of your firing chamber and pull out the firing pin/spring. Take off the rusty spring. Put on a new spring. Put the pin/spring back in. Glue it back on with epoxy. I may have some pics of this lying around. If I do I will post them here.

[Fishfan]

It's not leaking out of the nozzle though, and it's in my understanding that if it leaks out of the nozzle it's because the spring is old. It's leaking out the other end-where the firing pin is.
Also, I don't know where to cut either. It's not like other valves, the firing valve is on connected to the rest of the internals in a very weird way.

[marauder]

How bad is the leak?

[Fishfan]

Whenever I pressurize it, it leaks very fast. You can't keep it pressurized more than 5 minutes without pumping.

[DX]

That's not too bad of a leak...Ben's 275 leaked so crazily that when I was using it against a smaller gun, it soaked me more than hostile shots. Your problem is probably the O-ring or other seal in the valve. Could be misaligned, could be warped, I dunno. You'll still need to open it.

[Fishfan]

The question is, where?

[DX]

I'd assume that the main seal is in the widest part of the valve, so don't cut there. Probably should cut in the back left 3rd of the valve before the main section, but you'll need to wait for someone with more experience with small XPs.

[Neptune]

Cut open right at the fold, and then lube up the gromet/oring in the back. Then put in a new spring slightly smaller than the top grommet. I have a guide on it on here, it's a pretty simple repair when you get the hang of it

[Fishfan]

Neptune, where is it? I couldn't find the guide on the wiki.
Seal, maybe you could make a suggestion? I know you have cut open firing valves before.

[SEAL]

I somehow missed this before; sorry. Yes, I have cut open pull valves before, but they were small CPS valves (which are still quite a bit bigger than XP valves). I don't have much experience with XP valves, as I've only ever opened up one XP (well, XXP) blaster (my brother's 175, so I could insert my homemade pump), and never did anything with the valve.

However, I should think that XP valves are no different than CPS valves except in size, so you could probably do the same thing to open it. What I did was simply take a hacksaw, and sawed all around the seam on the fat part of the valve. Here's the thing though; when you've sawed deep enough to see the inside of the valve, STOP. If you keep sawing you risk damaging the internals. Just do that all around the valve, and it should pop open. It's actually quite simple, despite the intimidation factor. Just remember to try to hold the saw straight while you're cutting.

Does that help? I can draw a picture if you have trouble visualizing it.

[Fishfan]

Yes, it does. I'll draw a line on the pic that I have just for clarification.
Edit: Here it is!

Is that where I cut it? And through the pipe that connects to it?

[SEAL]

If there's a seam where that line is, then yes. I've never seen a valve attached to a pipe like that before, but if the seam goes around the whole thing, you should be good to go.

[Fishfan]

well, there isn't a seam there. There seems to be one right after the pipe ends though. I think I'll cut there and just hope for the best.

[SEAL]

Good luck! Don't forget to take pictures. I'm curious to know what an XP 70 valve looks like on the inside.

[Fishfan]

Thanks, I'm going to need it. Really nervous about cutting open the valve.