GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: larspawn on March 02, 2014, 04:30:14 PM

Title: FDPCP issue
Post by: larspawn on March 02, 2014, 04:30:14 PM
FDPCP


5 shots
Off hand
10 yds
JSB heavies
900 FPS

Not bad.

Have problem though. Shot down to depressurization. Now can't fill gun. Air just leaks out barrel when bolt closed or out breech when open. What am I doing wrong?



Title: Re: FDPCP issue
Post by: rsterne on March 02, 2014, 04:35:57 PM
Cock the gun, the hammer is holding the valve open....

Bob
Title: Re: FDPCP issue
Post by: larspawn on March 02, 2014, 04:41:32 PM
Did that Bob. No dice. Any other ideas? 
Title: Re: FDPCP issue
Post by: mikeiniowa on March 02, 2014, 08:18:29 PM
valve is not closing for some reason, will have to tear into it and find out why or what is the problem...
Title: Re: FDPCP issue
Post by: larspawn on March 02, 2014, 09:38:53 PM
Can someone point me to FDPCP tear down procedure
Title: Re: FDPCP issue
Post by: mikeiniowa on March 02, 2014, 10:02:41 PM
should be one here in the fd venders on page two
Title: Re: FDPCP issue
Post by: toine on March 02, 2014, 11:55:07 PM
I've been archiving all the FDA-PCP posts on a google site. This page has the list:

https://sites.google.com/site/fdapcp/information-posts (https://sites.google.com/site/fdapcp/information-posts)

The specific post you are looking for is titled: How to take apart your FDA-PCP and its URL is http://www.gatewaytoairguns.org/GTA/index.php?topic=62012.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=62012.0)
Title: Re: FDPCP issue
Post by: airgunwarriors on March 12, 2014, 05:18:52 PM
FDPCP


5 shots
Off hand
10 yds
JSB heavies
900 FPS

Not bad.

Have problem though. Shot down to depressurization. Now can't fill gun. Air just leaks out barrel when bolt closed or out breech when open. What am I doing wrong?

I know that I am posting late on this issue, but wanted to let you know that when I shoot mine down too low, it too loses its seal.

So, I simply pump rapidly until it self seals and stops leaking.

Not sure if it would be that easy for others?

I do this with the gun cocked, bolt pulled back by the way.

Respectfully,

Al.
Title: Re: FDPCP issue
Post by: Fwawa20 on March 13, 2014, 02:40:04 PM
Any updates on this I just had this happen to me and I can't fill my gun now. Wondering what I need to do? I know that having it cocked and pumping isn't working in my situation. Any advice?
Title: Re: FDPCP issue
Post by: larspawn on March 13, 2014, 10:52:20 PM
Yes I fixed it. Are you hand pumping?  Might not work for you if you are.

The valve must have gotten stuck. I freed it by filling really fast from my tank. Normally I fill slowly but I just jammed it open. Kinda like seating the bead on a tire.  Bam!

Got it to hold except I overfilled to like 1800psi. Then I got valve lock. Yay me!  I left it outside in about 18 degree weather over night which brought pressure down enough for me to purge some off by dry firing. It's been fine through a dozen or more fills.

I also notice if I fill to 1500 the striker isn't strong enough so I have to fill at 1400 or less. If I fill to 1500 the first 4 shots are like 350 FPS.
Title: Re: FDPCP issue
Post by: mikeiniowa on March 14, 2014, 07:51:29 AM
the striker springs vary somewhat in strength, a 1/4 inch spacer or less will help to get it to open the valve at 1500 psi if it's too weak...
Title: Re: FDPCP issue
Post by: Fwawa20 on March 14, 2014, 11:28:11 AM
Yes I am hand pumping and it's not working. If anyone has any other ideas about how to fix the problem I would greatly appreciate it. If I have to tear it down I will but I'm just hesitant being that this is my first pcp
Title: Re: FDPCP issue
Post by: mikeiniowa on March 14, 2014, 07:17:49 PM
When you decide to tear into it remove the fill cap first...if you can't get it to turn off with your fingers then there is pressure in the rifle...
Title: Re: FDPCP issue
Post by: larspawn on March 14, 2014, 09:53:23 PM
Where are you?  Maybe there's someone close by with a tank that can jump start you?  Or any paintballers nearby?  Once seated I'd say don't shoot down below 800psi?
Title: Re: FDPCP issue
Post by: Fwawa20 on March 14, 2014, 11:00:07 PM
Ya. I was thinking that same thing. I'm in N.C. near Asheville area.
Title: Re: FDPCP issue
Post by: mikeiniowa on March 15, 2014, 07:05:08 AM
don't be afraid to tear into it, there is a disassembly guide here...to get to the valve...remove elevation screw in rear sight, remove the screws holding sight(rear one is a bit tricky), remove set screw under sight that holds barrel(2.5mm), remove forestock screw under forestock, pull barrel out the front(may need a twist to get started but will pull out), unscrew tube(may need pliers to get it started) by hand, remove square o-ring by valve, loosen valve by unscrewing 1/2 turn with needle nose pliers in cutouts, remove font screw under action that holds valve, use needle nose pliers in cut outs to pull valve(may need to pry on valve in screw hole to get started, use small screwdriver of allen wrench), unscrew havles and see what the seal looks like first it may have debris on it or could be defective(some have had the seal pop out of the brass head) clean seal well even a tiny fleck of dirt will cause leak, I use a magnifying glass and bright light to check it, when reassembling use your hands to tighten tube only, the threads hold more pressure than you would think so just hand tight, once tube is in place then test to see if it holds pressure, go to about 500 psi and if it's holding reassemble the rest...need parts let me know
Title: Re: FDPCP issue
Post by: ScarletFire186304 on April 20, 2014, 01:09:23 AM
i've been having the same problem.

dove in head first. i found a bad seal.  8)

bob
Title: Re: FDPCP issue
Post by: ScarletFire186304 on April 20, 2014, 02:04:16 AM
here's a couple pics ( i hope)   8)

Title: Re: FDPCP issue
Post by: mikeiniowa on April 20, 2014, 07:47:46 AM
parts are available if you need them...the seals on the second gen look much better than the first so the stem problem may be solved, if you have one that's bad let me know
Title: Re: FDPCP issue
Post by: ScarletFire186304 on April 20, 2014, 03:57:35 PM
is mine missing a part?

this pic is from this post:

http://www.gatewaytoairguns.org/GTA/index.php?topic=60924.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=60924.0)

or is this an earlier or different valve than mine? there is nothing behind my spring but a washer. 
mine is a .177 that is a .22  8)

bob
Title: Re: FDPCP issue
Post by: Fwawa20 on April 20, 2014, 04:46:41 PM
The seal on mine looked like that and I managed to push it back in but it's still not holding air. It'll fire a couple very low power shots then it will relieve all of the air.
Title: Re: FDPCP issue
Post by: Fwawa20 on April 20, 2014, 04:53:51 PM
Maybe this could be an issue looks to be off center if you look very carefully.

(http://i1144.photobucket.com/albums/o489/Fwawa2O/Mobile%20Uploads/2014-01/CA102643-C171-483C-801C-3A26827EE3DD_zps20kfxcmw.jpg) (http://s1144.photobucket.com/user/Fwawa2O/media/Mobile%20Uploads/2014-01/CA102643-C171-483C-801C-3A26827EE3DD_zps20kfxcmw.jpg.html)
Title: Re: FDPCP issue
Post by: Yarp on April 20, 2014, 09:27:46 PM
Definitely off center.
.. also..looks like a little polishing would not hurt.....perhaps a light buffing with jeweler's rouge will seal the deal despite what looks to be random machining. 
Title: Re: FDPCP issue
Post by: Fwawa20 on April 21, 2014, 09:46:13 AM
Yea I did just about everything in my power to fix this so I might just be sending it back to mike to do it for me.  New to pcp game jumped in head first and drowned, but I think the only reason is bc that parts of center and it refuses to make a good seal. The rifle inside itself is pretty basic not hard to disassemble and a great learning tool. I jus don't have to tools and confidence to touch that piece.. I'd just like to have it done right by mike. I was wondering is this a good seal or no? It'll get sucked out jus about every time I pull it apart but I jus push it back down in the stem.

(http://i1144.photobucket.com/albums/o489/Fwawa2O/Mobile%20Uploads/2014-01/F2A5EBB4-DF4A-4E5A-ABFD-695F681565B5_zpsrgm8mvib.jpg) (http://s1144.photobucket.com/user/Fwawa2O/media/Mobile%20Uploads/2014-01/F2A5EBB4-DF4A-4E5A-ABFD-695F681565B5_zpsrgm8mvib.jpg.html)
Title: Re: FDPCP issue
Post by: Yarp on April 21, 2014, 04:12:20 PM
Have you called Mike for suggestions?
If you do so during business hours, he'll likely pick up.
Title: Re: FDPCP issue
Post by: mikeiniowa on April 21, 2014, 07:34:17 PM
you have one of the fat seals...the second gens seem to have that fixed. What I have been doing is to sand or cut them down to be level with the side of the brass head, I think the air going around the edge of the fat seals not worthy them out of the head...can send parts if needed...
Title: Re: FDPCP issue
Post by: ScarletFire186304 on May 21, 2014, 05:25:34 PM
has anyone tried replacing the stem and spring and washer from a qb78 inside one of these valve that is doing this (sucking out the plastic seal)?  8)

bob
Title: Re: FDPCP issue
Post by: mikeiniowa on May 22, 2014, 08:59:04 AM
the QB stems will work but...the shaft is a smaller diameter and will need to be sealed at the rear of the valve head...xs stems are available and brass heads for the valve body if you are having problems with the seal sucking out...
Title: Re: FDPCP issue
Post by: Kowboi on July 12, 2014, 04:11:58 PM
is mine missing a part?

this pic is from this post:

http://www.gatewaytoairguns.org/GTA/index.php?topic=60924.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=60924.0)

or is this an earlier or different valve than mine? there is nothing behind my spring but a washer. 
mine is a .177 that is a .22  8)

bob

All I have is a washer behind mine as well.
Title: Re: FDPCP issue
Post by: ScarletFire186304 on July 12, 2014, 05:39:45 PM
yeah, i was off base on that one.

if you read the thread closely, he (Nick) made that extra piece and put it in there.

my bad!   8)

bob