Retro Valve Velocity Issue

[cbstalter]

I have a retro valve that has just been rebuilt. Well really just had a new on/off, reg. piston, and reg. pin assy. installed.

The valve does have a lvl x installed and I am using the shortest spring, no shims, and #1 bushing.

Took it out to the local field today and figured the fps would either need to come down or be below 300 which is required.

345 to 355 all three times on the chrono. This was with the adjustment screw turned out to the point where if I backed it out anymore it wouldn't seal and begin to leak.

I'm lucky enough to have an AGD tech that works there. Immediately he said reg. pin assy. needs replaced. So now I'm confused as it is new and I'm not sure where else the issue could be.

Needles to say, my day was cut short. No play time and now I am turning to AO for some help. Thanks.

[Xyxyll]

Ahh that sucks. I can't verify that this is the solution without spending some time with the marker on the bench, but I suspect this is what he's referring to: http://www.airgundesigns.com/product-p/000843.htm

[cbstalter]

Ahh that sucks. I can't verify that this is the solution without spending some time with the marker on the bench, but I suspect this is what he's referring to: http://www.airgundesigns.com/product-p/000843.htm

That is exactly what he is talking about. But like I said I just replaced that entire assembly back in April.

[vintage]

are you sure he didn't say REG piston?

[cbstalter]

are you sure he didn't say REG piston?

Pretty sure he said reg. pin. assembly. But either way, the reg. piston was replaced at the same time. The gun had been sitting for about 15 years and the old one was venting out the back. No more venting, just super high velocity that won't come down.

[vintage]

make sure the little spring washers have not collapsed on the reg pin, I would not think they would on a new one but you never know. what was wrong with the old pin?

[cbstalter]

make sure the little spring washers have not collapsed on the reg pin, I would not think they would on a new one but you never know. what was wrong with the old pin?

I'm gonna pull it back out and take a look at the spring washers. As for the old pin, probably nothing wrong with it. I just swapped it when I put the new reg. piston in.

I did swap it the other day at the field to see if it was the new reg. pin. But the velocity was still between 345 and 355.

At this point I am not really sure what to do outside of getting a new reg. pin. Might re-tune the level 10. I did tune it the first time with the velocity adjustment screwed all the way in. Course don't know if that would make any difference or not.

[vintage]

i don't know unless your spring pack is jamming your reg piston.

[rawbutter]

i don't know unless your spring pack is jamming your reg piston.

This was my first thought. A gummed up spring pack can cause problems like this.

[cbstalter]

This was my first thought. A gummed up spring pack can cause problems like this.

Yea. I'm gonna pull it all apart and clean everything and give it some fresh oil and grease. I did order a new reg. seat today. Saw another post about a similar issue and it was the reg seat. Course I was taking a look at it this morning, aired it up and had it leaking out of the back through the velocity adjustment as well as the weep hole on top of the valve.

So until the new reg. seat comes in, I'm not touching it.

[cbstalter]

Ok, so the new reg. seat came in along with the 4 pack of o-rings for the reg. pin assembly.

Got everything changed out and oiled. Put the valve back together and aired up. Still leaking out of the back of the velocity adjustment, along with the weep hole on top of the valve. I screwed the velocity nut all the way in and all the way out with no difference.

My tank is putting out 800 PSI, so im pretty sure that is not the issue. At this point I dont know what is left to try. The reg. pin assy., the reg. seat, and the reg piston are all new and have had the o-rings changed 3 times now.

I saw a post by BlackVCG with directions on breaking down this valve and re-assembling it.

I have not even checked the velocity now that it is leaking out of the back.

Any help is greatly appreciated. Honestly I am at the point where I will send it to someone to look at for me or wing it out into the street.

[Tunaman]

did the orings fit snug on the reg pin? Do you have the plastic split washer in between the orings? Are you installing the small oring in the back half of the valve before assembling? You changed the reg seat /L10 oring? check for debris down in the reg pin hole. Let us know.

[vintage]

leaking out the weep hole is the reg pin. i can tell you from experience that i have had several valves that would leak with new pins or o rings and i had to take them out multiple times and wipe them off, blow the hole in the valve out before they would seal and i could not find anything wrong with either, best guess was a microscopic piece of trash.

leaking out the back is the piston, i've not had a lot of trouble with that using new pistons so i really can't offer much.

[cbstalter]

did the orings fit snug on the reg pin? Do you have the plastic split washer in between the orings? Are you installing the small oring in the back half of the valve before assembling? You changed the reg seat /L10 oring? check for debris down in the reg pin hole. Let us know.

1: The o-rings fit snug on the reg pin.
2: The plastic split washer is there between the o-rings.
3: The o-ring is getting installed into the back half of the valve before assembly.
4: Both the reg seat and reg seat holder (brass clover shaped piece) have been replaced. And as far as the L10 o-ring, it is new and was the one that fit the best when I installed the new kit.
5: Pulled the reg pin out and checked it for debris. Went ahead and blew it out just good measure.

The weep hole that is is leaking from is the one on the back half of the valve, located above the piston.

[Tunaman]

1: The o-rings fit snug on the reg pin.
2: The plastic split washer is there between the o-rings.
3: The o-ring is getting installed into the back half of the valve before assembly.
4: Both the reg seat and reg seat holder (brass clover shaped piece) have been replaced. And as far as the L10 o-ring, it is new and was the one that fit the best when I installed the new kit.
5: Pulled the reg pin out and checked it for debris. Went ahead and blew it out just good measure.

The weep hole that is is leaking from is the one on the back half of the valve, located above the piston.

I would concentrate on that reg pin. Try flipping the orings. Flip the L10/reg (not the one in the L10 carrier)seat oring too

[vintage]

if you have access to a magnifying glass you might check for a burr on the inside of the valve where the pin goes.

[cbstalter]

I would concentrate on that reg pin. Try flipping the orings. Flip the L10/reg (not the one in the L10 carrier)seat oring too

So, I took apart the reg pin assembly, blew it off and flipped all the O-rings. Added hole and put it back in. Also pulled the piston out of the back half, took the O-ring off and noticed brass shavings. So that got cleaned and a new O-ring.

Aired it up, no leaks.

Not out of the woods yet though. Still need to get some paint in it and on a Chrono to see if the velocity issue has been taken care of since that was the original problem before the leak appeared.

But just wanted to send out a huge thank you to Tunaman and vintage for the help. Still may need your assistance if the velocity won't come down.

[cbstalter]

So got some paint through it this morning on the chrono. 205 fps, this is with the adjustment but turned all the out. Not sure how much I trust my little handheld chrono.

But one last question. The o-ring that sits in the back half of the valve, that the reg. pin assembly goes through keeps popping out into the reg. seat holder causing the gun to go full auto. Take everything apart and put the o-ring back in it's proper place and it works great.

Is there anyway to make sure that o-ring stays in place?

[Xyxyll]

Are you talking about 31 or 34?

[cbstalter]

Are you talking about 31 or 34?

34. I've read conflicting posts on where this is supposed to go. Just want to make sure I have it in the right place.

Also read it may be the on/off. But the gun has no leaks when aired up with the trigger pulled. Which is also the first question asked when others are having this full auto issue.

[Xyxyll]

Hmm, I'm pretty sure mine (34) often push into the reg seat holder (32) with no issues. Is your trigger rod the right length?

[cbstalter]

Hmm, I'm pretty sure mine (34) often push into the reg seat holder (32) with no issues. Is your trigger rod the right length?

It is a new x-frame. Factory preset, so I've never checked it.

It's just weird cause if I pull the o-ring out of the reg holder and put it in the back half of the valve. The gun works fine until it gets pushed into the holder.

[cbstalter]

Got it back on the chrono. First few shots, well over 300, 345 to 350. Shot it again, held the trigger back, released just a bit until I could hear it click. Fired, and the velocity was well under 300, 265 to 275. I could get these readings consistently.

But...if I let the trigger all the way out and then shot, velocity went right back up to over 300. Order new L10 o-rings and a new reg pin assembly.

[Tunaman]

Got it back on the chrono. First few shots, well over 300, 345 to 350. Shot it again, held the trigger back, released just a bit until I could hear it click. Fired, and the velocity was well under 300, 265 to 275. I could get these readings consistently.

But...if I let the trigger all the way out and then shot, velocity went right back up to over 300. Order new L10 o-rings and a new reg pin assembly.

The proper way to chrono these valves is to hold the trigger back, quick release and hold trigger back again. As you see the readings will be quite different when you do it right.