Cuda Tears Apart a Classic RT Mag!

[Cdn_Cuda]

To little surprise my new to me RT Mag leaks form everywhere! So I’ll be taking ur apart, replacing some ancient o-rings and hopefully break my mag curse and get this one to actually works.

Update: I was using a retro mag rebuilt kit and not the proper RT mag rebuilt kit. After my initial issues I bought a proper RT mag kit and am installing it.

I made several mistakes in my initial rebuild but have tried to label them, so please read through the thread first to see my corrections. In the end I have a fully functioning RT mag, thanks to the help of fellow MCB members!

[Cdn_Cuda]

So start with the easy stuff, removing the twist lock barrel and remove the 6 bolts that hold on the sight rail.



Then I remove the rear frame screw which is actually a banjo bolt that goes into the valve. This is essentially the only component hold the two sections of the body together, so the rail and grip frame can be moved to the side.



Note on the RT Mag the airline to the valve is integrated into the rear frame bolt, unlike pretty much all other mags.

[Cdn_Cuda]

Here’s the sear and inside of the rail and a look at those nice wood grips.



With the lower half of the marker removed I can get into the main body and valve. There’s a little cut out in the body and a bolt that sticks out on the valve to hold the valve roughly in place. You need to press the valve straight in a bit to line up the banjo bolt. Kinda need 3 hands to do it all, but I am getting better at it.

[Cdn_Cuda]

Now onto the meat and potatoes for the Mag, the valve.

Full valve with bolt and spring:


Now takes a few pieces off:



And then start disassembling the bolt tip, and the internal spacer that sits above the o-ring:
Note: the brown o-ring show. On the black reg piece is incorrect and cause a leak down my body. It needs to be a 017 oring, which did not appear to come with my rebuilt kit. The 018 o-ring provided with the o-ring kit as too big to use here.

[Cdn_Cuda]

And let’s get a little more in depth with the power tube:
(Note blue bumper is incorrect bumper. Correct bumper is clear. Blue is for a classic mag.)

Using a quarter in the easier way to remove it:



And then you can see the spacer, which can be easily removed and flung across the shop floor as it is loose….

And then there’s the internal o-ring:



And in the back of this piece is the reg internal:

The main portion is a single non-repairable stack and there’s the pin and two o-rings at the back (to the left).

Update: the stack is repairable and just is shown later in this thread.

[Cdn_Cuda]

That brings us to the on/off:

Note: this shows two standard o-rings that I have since replaced with proper o-rings from an RT rebuilt.



Which has several o-rings and needs to be disassembled to access them all:



And then it can be inserted back into the main valve body:

[Cdn_Cuda]

And now the final portion is the rear of the valve where you adjust velocity. Simply unscrew it and tap out the internals to find the final o-ring. Note their are two springs, one inside the other.

[Cdn_Cuda]

So now you can put it all back together, ensuring you sign the body and valve properly.



These RT rails don’t leave the little notch that sits in the rail making it easier to align the rail.

And finish off by making sure you align your barrel properly and the feed port in the body and barrel align properly.

[Cdn_Cuda]

So I did use standard o-rings in a couple places so we will see if they come back to bite me. I’ve got some loctite drying on the on/off so tomorrow I’ll see how bad it leaks of if it wants to cooperate.

[Trbo323]

If it doesn't work, It's because you used the wrong quarter to take the power tube apart. It's an American made marker

[Cdn_Cuda]

Ah, I used a metric quarter instead of an Imperial quarter. I keep both on my bench just in case. Easy to mix them up though…

[Cdn_Cuda]

Vents down the barrel… not surprising as I didn’t have the right o-rings for my on/off. So going to have order a proper oring kit. Wondering if I can swap the on/off from one of my other mags? Going to compare them.

[Cdn_Cuda]

I now have a proper RT mag rebuild kit! Yeah, I know I should have done that first. Trying to use a classic mag kit wasn’t working. I also had my regulator valve pin needs to be rebuilt as one of the orings crumbled. For some reason I thought these weren’t rebuildable but was mistaken, so need to figure out how to remove the tiny clip on the end.

[LukeAO]

You dont have to remove the clip just stretch the orings over it.

[Cdn_Cuda]

Perfect. Was looking at it late last night and figured for once I should not try something dumb while being impatient.

[Spider!]

Make sure the power feed plug isn't original. The clear bolt bumpers are softer and a little more friendly for RT than the classic blue bumpers, if you are going that way.

[Cdn_Cuda]

I've put in the proper clear bolt bumper now that came with the kit.

[superman]

It is the more modern one, you can see from the shape in one of the other pics he posted.