Leaking 3-ways on Autocockers - What's the Deal?

[heit1_32]

I'm in need of some expert help/experience! I've been building lots of autocockers lately and I have quite a few used 3-ways that have persistent leaking problems which can't seem to be solved. I've verified I'm using the correct 3-way shafts and I replace and lube the o-rings. What causes leaking 3-ways that can't seem to be fixed? Or is this user error somehow?

I'd really like to not throw away a handful of 3-ways, but they just leak and can't be stopped. Different brands and styles. Leaks are always small but persistent regardless of adjustments I make. Leaks are never from the barbs, always from the chamber.

I understand the main causes:

1. bent 3-way shaft (using brand new ones)
2. bad o-rings (using brand new ones)
3. bad lubrication (freshly lubed)
4. incorrect 3-way shaft (using correct ones)
5. incorrect timing (timing adjustments make no difference to air leak)
6. LPR set too high (LPR is set at minimum pressure)

But I've checked each of these multiple times on each 3-way and they are not part of the problem. So... Am I the problem or do 3-ways just go bad sometimes?

It seems like the o-rings are just barely too small to correctly seal the chamber. As if the o-rings just need like 5-10 thousandths of an inch in additional diameter and they'd seal up.

Orings came direct from the o-ring store and from an autococker o-ring kit. size 002 - 70D (or 006 for psychoballistics or Empire has their own o-rings as well). As you can see I've done extensive research myself trying to figure this out and I simply can't determine what's happening. So here I am for the experts!

Edit, adding photo of my current pain in my ass 3-way. Really want this to work for the color match but damn if I'm not about to say screw it and throw a bomb 3 way on and be done 🤣

EDIT - I got this one working! I tried a few things but ultimately replaced 1 of the o-rings on the shaft and wiped most of the lube off and suddenly its running leak-free. So either I had a bad oring or it didn't like the grease, lol.

From all the feedback it sounds like 3-ways are just finicky in general. I'm gonna need to play with o-rings/lube and I now have a longer, more accurate, checklist of things to look at for troubleshooting.

[tyronejk]

In my limited autococker experience, 3ways are usually on the cusp of leaking to minimize drag on the trigger. I'd bet you can add a couple wraps of Teflon tape to the oring glands to add a little extra compression to the orings to get them to seal.

[heit1_32]

I was just kinda mulling over teflon but wasn't sure if it would stay in-place long term. But you know what, I'll bet a thin strip would have enough pressure on it to prevent it from slipping off. I'm going to try this as well! Probably try it without lubrication or with oil instead of grease. Thanks!

[heit1_32]

Unfortunately the teflon didn't work. It did at first, I thought it was a miracle, but it quickly fell off the o-rings after a few cycles and it was back to leaking. I don't know that I can get it to stick correctly when it's a moving assembly.

[tyronejk]

The way I do it first cut the tape into thin strips, equal in width to the oring gland. Then clean off any lube from the metal, wrap the tape tightly into the bottom of the groove, then install the oring on top. I haven't had issues with the tape falling off after this.

[Reflex0283]

I've found that sometimes lubing the o-rings will make them leak and have a lot of drag. I don't know why, but that's how my trilogy worked. Might be worth cleaning everything off and trying it dry if you haven't already

[heit1_32]

Will definitely try this! I can also try oil instead of a grease. Good troubleshooting ideas! : ) I can also try this without disassembling the front pneums so that's a win : )

[heit1_32]

DUDE! For some reason this actually worked, lol! Or I had a bad o-ring. I got out a chrome bomb 3-way and was about to give up and decided to give it 1 last try with no lube. Suddenly it's not leaking. I replaced 1 o-ring too. But she's running leak-free with no lube right now! Raw dogging it! I'll see how long it lasts, it's crazy to me that's it's working mostly dry.

[Reflex0283]

heit1_32 I really don't understand it but it just works!

[Drcemento]

I feel your pain...

• one of the dow lubes - I forget which one - maybe 55 does swell the orings slightly - that has resolved one persistent leak in the past - let them soak in it overnight before drawing conclusion.
• My daily driver cocker still leaks whenever I put my finger on the timing rod. sometimes a little wiggle there can stop a leak. similar to leaky airlines
• trying different O-rings from a different supplier
• Bad LPR seals - this was a biggie that nearly made me insane once. My brand new inception LPR had old bad seals right out of the box, and while it was not leaking on the LPR it was letting pressure past the ram seal and back through the 3way. who knows when the last time inception actually did a run of LPR's was so it could have been years old by the time it sold.

[heit1_32]

I'm using Dow 55 grease. I haven't soaked them in it but can certainly try! The leak seems the same today, they had 55 on them overnight but not soaking in it.

Like a freaking idiot I mixed 3 brands of the 003-70D rings together 😭😭😭 90% of them came from oring store, the rest from autocockerparts.com. I can try swapping rings again but they should all be quality. I can buy a small pack from another vendor too.

[Ecapnation]

DO NOT TEFLON THREE-WAY SHAFTS!!

1st.... Are you buying the right durometers and material type 003 orings? Are they made in china? I've seen crappy quality rings that have mould flashing on them still

2nd.... How are you putting them on? You could be stretching the oring out.

3rd .... Have you checked your ram seals? Sometimes that fails and makes it look like a persistent leaky three-way. While in reality its ram blow by.

4th.... What lube are you using to lubricate the threeway?

[heit1_32]

Yup the Teflon immediately fell off the orings, haha.

1. From the oring store https://www.theoringstore.com/store/
2. I'm using a pick to get them on, being careful not to stab them. It's possible I'm stretching too much.
3. I check LPR pressure by feeling the pump arm pressure. I've adjusted down to where the pump arm won't actuate and go back up and 3way leaks the whole time I have air to it. (Edit - I misunderstood this, I rebuild all my parts including the RAM. I don't use it if I can't rebuild it. I even replace the shitty little internal o ring in the RAM housing) I don't think it's RAM blowby because I can replace with a different 3 way and then it works 🤷♂️
4. Dow corning molykote formula 55 grease

[OpusX]

3rd .... Have you checked your ram seals? Sometimes that fails and makes it look like a persistent leaky three-way. While in reality its ram blow by.

4th.... What lube are you using to lubricate the threeway?

^^These^^

Oil no grease. Also check the ram seals.

[Ecapnation]

^^These^^

Oil no grease. Also check the ram seals.

I'm going to die on the grease is the better option hill....

Back during PTI and wgp factory certification days Bud had us using grease..

Personally grease will stay put in the oring glands and in some cases help swell crap o-rings.

After all the threeway is a type of spool valve.. we don't use oil in those guns it will just back flow into the ram and lpr

[heit1_32]

Well why didn't you tell me about #33 before I bought this giant $50 tube of 55 🤣🤣🤣 what are the benefits of 33?

[Ecapnation]

Its the bog standard paintball lube choice?

[heit1_32]

I absolutely hate it but I wiped most of the grease off and ran the 3-way shaft mostly dry and suddenly it's leak-free. LOL. I do lubrication on machinery for work so this drives me nuts that it's working with very limited lubrication. I also replaced 1 of the orings so it was probably a poor-fitting oring but I'm too afraid to touch it again now that it's working so it's gonna stay dry!

[latches109]

I didn't read everything above, but check the Inner diameter of the 3way is not scratched.

1. bad o-rings (using brand new ones)

The Outer Diameter of the oring is not enough, try a urethane or different brand. I've had many brand new ones leak and when measured by calipers were not true 003 spec.
An old school trick it to wrap some PTFE tape round the shaft and then put the oring on to increase the OD.

[heit1_32]

Thanks dude! I did replace one of the o-rings (and wiped most the lubrication off) and suddenly it's running leak-free. It was likely a bad fitting o-ring. It doesn't surprise me that some aren't true 003 spec and the tolerances on the 3-way have to be pretty tight so any o-ring size deviation is a bad thing. Maybe measuring them before putting them on would be a good practice for me to adapt.

I dig the PTFE tape on the shaft with the o-ring on top idea. DUH - that makes way more sense than my dumb brained idea that I tried with the tape on the outside. These are the types of old school tricks I like to hear about!

[Drcemento]

sorry - RAM blowby was my issue - not the LPR seals, though those needed to be changed to!

[Hellion360]

One time I had a gun that I sold locally and it had an intermittent mystery leak on the 3-way after/during its first day of use. So I took it back to service. It had an eyelash stuck in the spool. That was the weirdest one.

I have also run into WGP 3-ways, using wgp spools and they just didn't match up right. Like both parts were just out of spec enough in opposite directions that it wouldn't seal no matter what. Swapped to a different body and the spool sealed up. The other body with a new spool also sealed up.

[Buff_phroggie]

Some are just finicky, and some want higher pressure, othsrs want lower

[Pumpytrilly1]

My system x 3 way likes plumbers tape in thin strips wrapped around it before putting the oring on. Others are fine. I normally lube them with dow 33