Pump-Mag Problem, NEED HELP!

[RPI_magman]

Hey guys! I'm having some trouble with a pump-mag I put together a couple months back. I'll give a quick run-down of the gun set-up, symptoms I've noticed and the fixes I've already tried. I'm a pretty handy guy, and an engineer, so feel free to get technical with your suggestions. I'm stumped and I would really appreciate any useful suggestions. Thanks!

Set-up:
Classic 68 valve, stock grip, eclipse rail, Level 7 bolt, XM-15 pump kit, ULE body, compressed air.

Issues:
Air leaks down the barrel when the marker is gassed up, leaking stops when the trigger is pulled and held, leaking stops when the valve is pushed forward into the body

Fixes tried:
New power tube o-ring, power tube spacer kit (tried all of them!), tried the valve minus the wave spring (semi-auto set-up), even put the valve/bolt assembly from my other mag (mini-mag valve with Level 10) and it stilled leaked!

Suggestions please!

[need4reebs]

did you try tightening your field strip screw?

[wimag]

Do you have the bolt bumper on? If so remove it. I had a similar issue and that took care of it.

[211]

rail bushing?

[Fatalis]

rail bushing?

SECOND

[captian pinky]

had the same thing happen this weekend

classic valve
lvl 7
taso rail
ule body
properly adjusted sear

i checked the orings in the powertube and on/off

i switched over to a lvl 10 as stated by Geoff Call from PBC and now shoots great.

i know this may not help because you have a lvl 7 but i had a spare lvl 10 laying around hope this helped some. Also make sure you have a rail bushing and field strip screw is tightened just right.

[RPI_magman]

Thanks guys. I'll tinker with it later today and see if those fixes work for me. I'll post later with results.

[Ando]

80% of the time when converting over to pump, it will leak down the barrel. The fix for that is a shorter PT spacer. A .220 spacer is the money spacer. If you already tried that. Toss in another lvl 7 bolt with the .220 spacer.

If all else fails, grinding a TP spacer with a dremal would be your next option but I would do that as a last resort. If you go this route, make sure you put the grinded side towards the bolt and PT tip. Tthe ungrinded side towards the oring and the plastic keeper/washer.

You'll also need to cut down your bolt bumper so that it fits perfectly inside the diameter of your wave spring. The bumpers only purpose in life is to keep the spring centered on the PT.

Besides that you should be good.

EDIT:

If it's still in semi mode, you'll need to cut the main spring down some. The main spring is basicly counter reacting the wave spring. Cut half a link at a time till it stops cocking itself.

i switched over to a lvl 10 as stated by Geoff Call from PBC and now shoots great.

I would highly recommend converting your pump rod over to a brass one, especially on a lvl 10 bolt. Those pump rods will eat the bolt eventually, especially if it's not set up correctly. You can find them at any hobby store. They cost $1.50 (compared to a $35 lvl 7 or $45 for a lvl 10 bolt) and the size is 3/32. That's the only size my hobby shop carries that will work. It's just a tab bit skinnier then the actual rod used but it works

The rod is suppose to be a 1/8 but depending on the China-man that was making the stock wire that day. All mine measure out too 7/64.

[Fatalis]

.

I would highly recommend converting your pump rod over to a brass one, especially on a lvl 10 bolt. Those pump rods will eat the bolt eventually, especially if it's not set up correctly. You can find them at any hobby store. They cost $1.50 (compared to a $35 lvl 7 or $45 for a lvl 10 bolt) and the size is 3/32. That's the only size my hobby shop carries that will work. It's just a tab bit skinnier then the actual rod used but it works

The rod is suppose to be a 1/8 but depending on the China-man that was making the stock wire that day. All mine are measure out too 7/64.

Any other modding that is needed to the brass pump rod? Do you need to bend it or have it threaded?

[Ando]

You have a rainman kit? I think the diameter of the brass rod might be too small. The threads will probably be to shallow when you cut them and just strip out on the first few pulls. Just make it to the exactly specs as the stock rod and you can't go wrong but you might need to find the proper size rod if you have a rainman kit. The rest of the kits will be fine with the 3/32 rod.

[RPI_magman]

It Lives!

Rail bushing FTW! I discovered that the Eclipse rail that came with the gun did not come with a bushing. I pirated one from my other mag for test purposes, and the gun works!

I had another issue, which was that the gun was not discharging fully when it fired. It sounded like a chuff on a level 10 set-up. Lesson learned, if your pump-mag chuffs, you bent the pump rod. Easy fix - bend it back - but that baffled me for a while.

Anyways, i got it working! Thanks everyone for your help!

[robander3]

Rail bushing FTW! I discovered that the Eclipse rail that came with the gun did not come with a bushing. I pirated one from my other mag for test purposes, and the gun works!

I had another issue, which was that the gun was not discharging fully when it fired. It sounded like a chuff on a level 10 set-up. Lesson learned, if your pump-mag chuffs, you bent the pump rod. Easy fix - bend it back - but that baffled me for a while.

Anyways, i got it working! Thanks everyone for your help!

I have a spare bushing I can give you when we go to ASC next...
-Rob

[RPI_magman]

Thanks Rob. However I ordered bushings and some misc. o-rings from AGD already, so I should be in good shape. Thanks though!

[Fatalis]

You have a rainman kit? I think the diameter of the rod might be too small. The threads will probably be to shallow when you cut them and just strip out on the first few pulls. Just make it to the exactly specs as the stock rod and you can't go wrong but you might need to find the proper size rod if you have a rainman kit. The rest of the kits will be fine with the 3/32 rod.

Yeah, I have a rainman one. I get lots of binding from the rod I have now. Think it may be a tad to big for the groove. Waiting on my ULE back from Luke before I can test it all out. Might go buy one of the craft stores and pic up some brass rods and see what happens.

[Ando]

Are you sure it's the rod doing it and not the handle? The new batch of Rainman kits he did are kind of hit and miss. There was an issue with a few of them binding inside the grip. I sent mine back to Rainman and he fixed it free of charge.