Opening a G&G M4 Pneumatic Blowback Mechbox

flack · September 9th, 2009, 15:31

Hello there!

I Want to upgrade my G&G m4 PBB but I don't understand how you are suposed to remove the blowback assembly.

Theres no screws on the top part of the mech box, its seems to be held in place with the blowback cylinder and/or a little metal strip. I already almost stab myself in the leg trying to slide it back with a screw driver but it doesnt move at all!

Anyone opened a PBB mechbox before?

Thx for looking

m102404 · September 9th, 2009, 15:38

Yeah, unhook the fake bolt plates...unclip the spring....

The black shell slides off of the rest of the assembly, then you just lift it out of place.

Pretty much...whatever looks like it'll come apart, take apart.

Tys

Tex · September 9th, 2009, 15:40

you will need to get that gearbox out of the body too.

flack · September 9th, 2009, 15:50

sry i forgot to tell you this isnt my Picture!!

My Mechbox is already out of the body, the fake bolt is removed, all the screws are removed! Its not my first mechbox, just my first PBB!

I managed to slide the strip backward but the blowback cylinder wont move backward... the mechbox split from everywhere but under the blowback cylinder! I'm soo affraid to destroy something... replacement parts are hard to find! Any tips on how to remove this cylinder?

thx guys

m102404 · September 9th, 2009, 16:04

I think that you need to remove the e-clip that is holding onto the end of the piston rod.

It's been a long time since I've taken one of these apart. I kind of refuse to work on them now.

Tys

flack · September 9th, 2009, 17:42

I got it, you just need to use an isane amount of force (or some little tap with a screw driver) to pull back the "sleeve" around the blowback piston!

thx anyway, i kinda understand why you refuse to work on them...

m102404 · September 9th, 2009, 17:44

I probably tap harder than you...LOL

(sharp edges though, don't slice your fingers)

IceTray · September 9th, 2009, 19:12

Its weird, I'm having the same problem, I cant get the fake tin bolt off, despite reading Tys explanation, haha.
Don't suppose youd might have a photo or two to assist in explaining the process?

m102404 · September 9th, 2009, 19:56

It just "unhooks"...it's fiddly, but it just comes apart. No secret twists or angles to pull at.

Take your time, undo whatever is clipped/slotted into something else.

If in doubt, take it to a gun doc who's done it before. (Be nice and have the mechbox out already).

There's not much too lose (but if I recall correctly the spring keeps falling off). Once you have the piggy back piston off, you'll see a rubber (the ones I worked on were lime green) gasket in the top of the mechbox shell. Don't tear or loose that. It only goes one way into things so look at it carefully as you open the mechbox shell.

If you tear/lose that gasket you're FUBAR'd and your rifle is dead.

Tys

flack · September 9th, 2009, 20:03

I had to bend the fake tin bolt a lot to remove it, I couldnt remove it from its rails... but I think you dont need to remove it first. You need to remove the E-clip that hold the Fake bolt, after you need to slide the metal strip I showed in the picture backward, than you will be able to pull back the black cylinder cover (where the bolt slides) and the fake bold will come with it.

Like M102404 said, everything is clipped/slotted...

I wish I didnt forget my camera... I will post picture this weekend!

Ohh and sorry for my quebec english lol

IceTray · September 9th, 2009, 20:34

Haha, yea I've gotten the charging upper cover off, and this is what I'm at now.

Basically, I can push that black cylinder cover all the way back, but it doesnt come off, so I get stuck there, haha.

flack · September 9th, 2009, 22:41

You need to take a flat screw driver and a hammer... im not kidding! put the screw driver just on the side of the cylinder cover in the front and hit gently... There is only 2mm thick of material so be carefull! And dont forget to remove the E clip holding the fake bolt to the piston rod

i just finished to put it back together and thrust me, the blowback assembly is a pain in the ass to assemble/disassemble!

mikeeeee · September 9th, 2009, 23:54

FLACKK how omg how did you remove the dust cover?? i cant figure out how to get it off PLEASE assist mee

IceTray · September 9th, 2009, 23:56

Quote:

Originally Posted by flack

You need to take a flat screw driver and a hammer... im not kidding! put the screw driver just on the side of the cylinder cover in the front and hit gently... There is only 2mm thick of material so be carefull! And dont forget to remove the E clip holding the fake bolt to the piston rod

i just finished to put it back together and thrust me, the blowback assembly is a pain in the ass to assemble/disassemble!

I've already done the whole smacking it back part, lol. Although it only goes so far before it cant go any further, and I'm unclear as of what to do after its been knocked back as far as it goes.

flack · September 10th, 2009, 00:45

I don't understand why yours doesnt come off it shouldnt stop anywhere... Are you sure you disconnected the fake bolt from the piston rod by removing the E-clip? thats the only thing that can stop it... My cover fell on the floor after the last smack lol

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September 9th, 2009, 15:31	#1
flack Trader rating Join Date: Jan 2005 Location: St-Bruno	Opening a G&G M4 Pneumatic Blowback Mechbox Hello there! I Want to upgrade my G&G m4 PBB but I don't understand how you are suposed to remove the blowback assembly. Theres no screws on the top part of the mech box, its seems to be held in place with the blowback cylinder and/or a little metal strip. I already almost stab myself in the leg trying to slide it back with a screw driver but it doesnt move at all! Anyone opened a PBB mechbox before? Thx for looking

September 9th, 2009, 15:40	#3
Tex Trader rating Join Date: Feb 2003 Location: Abbotsford, B.C.	you will need to get that gearbox out of the body too. __________________ W-69 _/\|

September 9th, 2009, 15:50	#4
flack Trader rating Join Date: Jan 2005 Location: St-Bruno	sry i forgot to tell you this isnt my Picture!! My Mechbox is already out of the body, the fake bolt is removed, all the screws are removed! Its not my first mechbox, just my first PBB! I managed to slide the strip backward but the blowback cylinder wont move backward... the mechbox split from everywhere but under the blowback cylinder! I'm soo affraid to destroy something... replacement parts are hard to find! Any tips on how to remove this cylinder? thx guys Last edited by flack; September 9th, 2009 at 16:01..

September 9th, 2009, 15:38	#2
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	Yeah, unhook the fake bolt plates...unclip the spring.... The black shell slides off of the rest of the assembly, then you just lift it out of place. Pretty much...whatever looks like it'll come apart, take apart. Tys

September 9th, 2009, 16:04	#5
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	I think that you need to remove the e-clip that is holding onto the end of the piston rod. It's been a long time since I've taken one of these apart. I kind of refuse to work on them now. Tys

September 9th, 2009, 17:42	#6
flack Trader rating Join Date: Jan 2005 Location: St-Bruno	I got it, you just need to use an isane amount of force (or some little tap with a screw driver) to pull back the "sleeve" around the blowback piston! thx anyway, i kinda understand why you refuse to work on them...

September 9th, 2009, 17:44	#7
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	I probably tap harder than you...LOL (sharp edges though, don't slice your fingers)

September 9th, 2009, 19:12	#8
IceTray Majestic Mornings rocking it like a Queen Trader rating Join Date: Jul 2007 Location: Windsor, ON	Its weird, I'm having the same problem, I cant get the fake tin bolt off, despite reading Tys explanation, haha. Don't suppose youd might have a photo or two to assist in explaining the process? __________________ I support Capital Airsoft! For anyone looking for age verification in the Windsor region: Unfortunately, I will only be verifying people at games, I am currently unable to run around and setup meetings.

September 9th, 2009, 19:56	#9
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	It just "unhooks"...it's fiddly, but it just comes apart. No secret twists or angles to pull at. Take your time, undo whatever is clipped/slotted into something else. If in doubt, take it to a gun doc who's done it before. (Be nice and have the mechbox out already). There's not much too lose (but if I recall correctly the spring keeps falling off). Once you have the piggy back piston off, you'll see a rubber (the ones I worked on were lime green) gasket in the top of the mechbox shell. Don't tear or loose that. It only goes one way into things so look at it carefully as you open the mechbox shell. If you tear/lose that gasket you're FUBAR'd and your rifle is dead. Tys

September 9th, 2009, 20:03	#10
flack Trader rating Join Date: Jan 2005 Location: St-Bruno	I had to bend the fake tin bolt a lot to remove it, I couldnt remove it from its rails... but I think you dont need to remove it first. You need to remove the E-clip that hold the Fake bolt, after you need to slide the metal strip I showed in the picture backward, than you will be able to pull back the black cylinder cover (where the bolt slides) and the fake bold will come with it. Like M102404 said, everything is clipped/slotted... I wish I didnt forget my camera... I will post picture this weekend! Ohh and sorry for my quebec english lol Last edited by flack; September 9th, 2009 at 20:06..

September 9th, 2009, 20:34	#11
IceTray Majestic Mornings rocking it like a Queen Trader rating Join Date: Jul 2007 Location: Windsor, ON	Haha, yea I've gotten the charging upper cover off, and this is what I'm at now. Basically, I can push that black cylinder cover all the way back, but it doesnt come off, so I get stuck there, haha. __________________ I support Capital Airsoft! For anyone looking for age verification in the Windsor region: Unfortunately, I will only be verifying people at games, I am currently unable to run around and setup meetings.

September 9th, 2009, 22:41	#12
flack Trader rating Join Date: Jan 2005 Location: St-Bruno	You need to take a flat screw driver and a hammer... im not kidding! put the screw driver just on the side of the cylinder cover in the front and hit gently... There is only 2mm thick of material so be carefull! And dont forget to remove the E clip holding the fake bolt to the piston rod i just finished to put it back together and thrust me, the blowback assembly is a pain in the ass to assemble/disassemble!

September 9th, 2009, 23:54	#13
mikeeeee Trader rating Join Date: Mar 2008 Location: ontario	m4 FLACKK how omg how did you remove the dust cover?? i cant figure out how to get it off PLEASE assist mee

Opening a G&G M4 Pneumatic Blowback Mechbox

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