Cupseal Change: Defiant

THE_Hulk · Posted: Tue Feb 10, 2009 2:25 am Post subject: Cupseal Change: Defiant

Hi, my cupseal is leaking. I have a new one and valve but how do I get the old one out and the new one in? I can belt the lower tube out except that.

Thanks,
Jim the Newb

MuthaFunk · Posted: Tue Feb 10, 2009 3:04 am Post subject: Re: Cupseal Change: Defiant

I'm not sure what your asking. There are three cupseals on a stock Bushmaster/Defiant

HPR, LPR, and Valve.

I'm going to guess you wish to replace the valve with a new one? You may get away with just replacing the valve stem with the new one you have. Remove the LPR and Spring. The valve stem will fall out. Relplace with new. If you wish to replace the valve stem cupseal you will have to unscrew the valve stem from the spring seat. Spittlebug could give you a better description on how to replace the stock valve cupseal. I have never really done it.

The cupseals in the regs are simple to remove and replace plus there are video's of it on PBN in the sticky's under ICD Bushmaster.

THE_Hulk · Posted: Tue Feb 10, 2009 9:47 pm Post subject: Re: Cupseal Change: Defiant

Thanks for the reply. It's at least the valve cup seal that needs replaced. I unscrewed the lpr cap, the spring popped out. There's a piece that's like steel in there. I can't get it out with pliers.

Any suggestions?

Thanks,
Jim the Newb

etipp98 · Posted: Tue Feb 10, 2009 9:57 pm Post subject: Re: Cupseal Change: Defiant

The valve stem? Are you looking into the body where you unscrewed the LPR? You will see the end of the vertical adapter screw as well in there...

MuthaFunk · Posted: Wed Feb 11, 2009 12:28 am Post subject: Re: Cupseal Change: Defiant

etip98 is right. You will see some screw threads on the bottom of the valve chamber where the Verticle ASA is attached to the body. Hopefully that is what you were having a hard time removing. If the valve stem is that difficult to remove, you have a problem.

Now that you have the spring and LPR out, you can push the bolt all the way foward and hold the body with the LPR opening facing down. The valve stem should slide out. If it doesn't it could be part of the sealing problem. The valve stem is binding in the valve body.

You will be able to tell by the bolt postion when you're forcing it all the way foward. You should be able to press the bolt pin all the way to the front of the slot. If it doesn't fall out, pull it out with needlenose pliers. If it's stock, it will have a brass spring seat.