Tiny Hop-up Rubber
 

This is my first time taking my CA M15A4. I'm doing some maintenance and changing a few things. I did a tonne of homework on the mech. box but CANNOT find out where that little tiny piece of hop-up rubber goes. (Im probally the only person on this site who doesn't know). Thks in advance

you'll have to take your hop-up apart, what you probably did was take the barrel out of the hopup with the hopup still engagued so it knocked it off. it goes on bottom of the little arm ( yours looks yellow). theres a little formed slot for it. but if its like mine it needs to be glued back into place. hope that helps a bit

It goes in the small hole in the hop up chamber ( between the rubber and the arm that pushes down when you dial the hop up). You have to hold the chamber upside down to put it back or it will fall out again

Damn you beat me to it ahahahhha :cheers:

awwwwwwww....thks alot. I would assume it goes in horizontal vs. vertical.
Can't I just un-wind the hop-up and place it back with a pair of needle nose (while upside-down)?

Now my next question.....the mech box is almost out but it's still farely snug. I have the selector switch still in and a pin that runs through the reciever and mech box. I dont want to damage the switch by prying it and that pin won't budge. What's my next move?

Turn your selector to the 11:00 position (between safe and semi), pull the cross pin and slide your mechbox out gently by lifting up on the rear.

You have to hit that pin out, after it's out, I suggest sanding it down.

It was a bitch for me the first time.

BTW, the small pin by the selector.

That's because you hit it out the wrong direction. One side is usually either tapered slightly or has ridges on it to keep it in the mechbox. Sanding it down will likely cause you to lose it in the field.

Not that it's necessarily a bad thing, but if you have some movement of your mechbox inside the body, it can be a bit of a hassle. Fire selection could become fussy. Remember, They put it in there for a reason.

yep, just as these gents said, IIRC on my G&P body it went in only one way, turn your body over so the selector switch is laying down and hit it out that way, your gonna need a punch and a hammer, BTW it can be a bitch to get back in. DONT sand it down or you could lose it like mcguyver said. The selector switch should be about 11 o clock too yea just pull from the back and lift it out

It was infact tapered and I was hitting it the right way, basically when I am suggesting is just sand the paint off it and maybe oil it.

It's still a bitch to get out, but it's now possible with a hammer and punch

It has zero movement and would never fall out in the field.

I think this must be common in the CA..

PERFECT...Thanks for help....It's all the little tricks that make things go easy. The Mech box came out perfectly! And to all those CA haters out there - after 5000 rounds the piston, head, and gears look BRAND NEW. Not a mark on the piston teeth. The gear box was also nicely lubed with white lithium. I feel kinda bad for upgrading to the Guarder FTK. Im also throwing in a 6.04 tightbore, metal bearing spring guide and a PDI 170. Gotta do someting about this hop-up rubber too.

Just FYI, the lithium in the chamber is the DIRECT cause of so many CA piston failures. It happens with G&G guns as well. Lithium will gum up and eventually offer so much resistance to piston movement that the sector gear will just chew right through the piston's teeth. I've seen it with CA M249, and many G&G guns.

When you go to install the new FTK, you can get CA cylinder grease from A&A for about $10. It looks like a silicone composition, pity they don't actually use it in their guns.

And yet another usefull tip..Thanks mcguyver

I managed to find that little piece of rubber.

Damn I hope I installed the barrel in right.