New ULT. Leaking and sticking problems

[Smokee_2_7]

After being out of paintball for the better part of the last 4 years, today I picked up a ULT kit for one of my x-valved 'mags.

After reading through almost everything I can find on the ULT, I'm still having a couple of problems:

1. There's a persistent leak from the on/off area. The air is escaping from the area where the valve meets up with the back of the ULE body. Placing my finger on this area results in a change in the pitch of the leak. I've already replaced the on/off top oring (the white one that the 'thick' head of the ULT pin seals off in to) as well as replaced the tiny black oring that the pin shaft goes through.
The larger, outer orings are VERY tight when I slide the ULT into the valve body, and I have lubed them generously. when holding down the trigger, the leak continues on for about 10 seconds before slowly fading away. The leak goes away immediately when I replace the ULT with my old RT on/off.

2. When firing with the ULT, i experience intermittent bolt stick. This may happen during either rapid or slow firing. The LX bolt will not fully reset, and requires a finger or squeege push to set the bolt that last couple of millimeters. This problem is also solved by switching back to the old RT on/off.



3. Oil. I've been using autolube for years, but have noticed much praise for KC trouble free. I'm sick of dry and brown o-rings all of the time. From what i've heard, the KC oil may be the solution.
Where can i get some? I can't seem to find a website for the company, and the only online stores i've found are either out of stock, or don't specify wether it's the blue or clear oil. One online store advertises KC with a pic of an autolube bottle.


Any help is greatly appreciated!


Thanks,


Carl

[Thanna]

Have you tried adding/subtracting shims to the ult?

[Smokee_2_7]

Well, I got rid of the leak. Had to replace every o-ring in the ult. Kinda bummed about having to rebuild a brand new kit from agd, but oh well.

Most recently, I had six ult shims installed. Just a few minutes ago, I dropped back to three shims. Aparently something magical happened, because the bolt reset problem seemed to stop.
Just put a tank of air through it, no bolt stick.

However, if I try to shoot anything over 5-6 bps, I can hear the distinct sound of shot drop-off. If I continue shooting quickly, then I start chuffing. My understanding suggests that this may be from too few shims.

Tank is a nitroduck ireg with an output of 1000psi.

I'm actually posting this from my phone, at the shop with access of plenty of air---
So I can try just about anything this afternoon.


Thanks,

Carl

[Coralis]

Do you have the shootdown with the rt on/off installed. As for the KC oil im pretty sure they dont make the blue stuff any more though if you google it you might find a online store that has some still.

[Spider-TW]

It seems pretty common for ULTs to take a full load of shims. There's an old thread about how many shims people were using and there were many that were stacked up.

Be sure and be consistent with how tight you set the frame and field strip screws. Besides keeping the body and valve aligned, when you stack a bunch of shims in the ULT you end up squeezing the on/off in there and you don't want to wrench it together or leave the valve body sitting on top of the on/off instead of the rail.

[Smokee_2_7]

Well, It looks as if I've got it figured out.

Pulled 2 shims out, and experienced the shoot down. Put one shim back in, and then double checked all the orings. I had a lot of oil in there, maybe too much. cleaned excess oil out of the valve/ reg assembly.

As of right now, i've put two tanks of air through it, and about two hoppers of old paint over the chrono.
+/- 5 fps with 6 month old (leaky) paint, and no shoot down!

Thanks to everyone for all their help. My biggest concern at this point is oil---- what is everyone using now if KC trouble free is no longer available? I just get sick of orings going hard and brown on me.


Thanks,

carl

[Spider-TW]

The makers a KC went out of business earlier this year iirc. There was much sadness. Like Coralis said, there may be some left over stock somewhere.

There's a few good threads on lubes. People have been happy with olive oil up to synthetic industrial air tool and air compressor oil. Synthetics don't encourage hardening of urethane like hydrocarbon oils, so most any lube that's synthetic and slippery is good.

Superlube oil has been good to me. Valvoline synthetic spray lube is good, but messy. The one I had trouble with is extreme rage marker oil, which is slippery but won't stay on an oring if you rub it between your fingers.

I haven't tried any vegetable or mineral oils. I bought some Superlube air tool oil, but haven't really given it a chance since it is thinner than the regular oil and doesn't appear to last as long.

If you find a sample of Krytox anywhere, it is an excellent synthetic grease and will preserve urethane orings a long time. It's good for coating static orings. I had a mag that spent over seven years in attics (over ten years in total down time) and came out usable. The urethane was discolored but good enough to work a few weekends until a rebuild kit came. But that was on a single trigger CO2 mag that didn't cycle as much or as fast as what I play now. High viscosity wasn't an issue.