I have an FX Streamline that I bought used that has started leaking from the vent hole at the rear of the cylinder. I think I have identified what needs to be replaced. My problem is that the cylinder doesn't want to come off. All of the pressure has been thoroughly bled out of the cylinder but it feels like it is really stuck on there. Is there a strap wrench that works for these small cylinders? Or is there some other method that people use to get these off? Would it help to use a little heat (hair dryer level, not torch)?
FX Leaky FX Streamline Questions
- Thread starter Yardstick
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Remove the barrel first so you have room and use both hands holding it at the gauge end side of the tube. That should be plenty of leverage. You can also put the gun on a vise with rubber pads
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I was hoping there was a way to do it without as much disassembly (didn't want to disturb the scope and barrel), but that seems like the only way. Thanks!
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That stupid plastic puck that seals the gauge is biggest weakness for the streamline. You have to tighten the gauge just right for it to seal. If the gauge is too tight or loose, air will vent out through that hole.
Don't know why FX tried to be different by using that puck and use orings like everyone else.
Don't know why FX tried to be different by using that puck and use orings like everyone else.
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This post on another leaky Streamline thread was very helpful: https://www.airgunnation.com/threads/leak-on-my-fx-streamline.392793/page-2#post-393851
But replacing the o-rings on the Regulator Sleeve (Regulator Seat in my diagram) didn't stop the leak from the vent hole on the cylinder. It looks like the next step is to replace the o-rings on the regulator body. If I have the right o-rings I might replace all of the o-rings in the regulator.
Is there a torque value for the set screws that hold the barrel?
But replacing the o-rings on the Regulator Sleeve (Regulator Seat in my diagram) didn't stop the leak from the vent hole on the cylinder. It looks like the next step is to replace the o-rings on the regulator body. If I have the right o-rings I might replace all of the o-rings in the regulator.
Is there a torque value for the set screws that hold the barrel?
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Snug, don’t over tighten. It’s aluminum after all. Wrap an Allen wrench in black tape and you can use it to help loosen the air tube. Make sure you grease the heck out of the threads when you go back together. Again just snug it, the o rings seal it. After you rebuild the reg, you may have to give it a little fast shot of air to seal the regulator o rings. And don’t be surprised if it doesn’t seal until 150-175bar. Another trick is to put an Allen wrench in the reg adjustment hole so it doesn’t move. Nothing more aggravating to get the gun to seal and find that the reg migrated one way or the other just enough to keep you from getting it back. Love my streamline, but it’s like an old dog, it may take some pets before it’ll fetch. Good hunting.
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When I initially pushed the regulator/sleeve assembly into the cylinder I did push the regulator out of the sleeve and into the cylinder a little bit. Not far enough for it to fall into the cylinder, but enough to let me know that they aren't connected like I thought they were. I gently pushed the regulator into the cylinder and then pulled the sleeve out before retrieving the regulator. I cleaned and re-lubed the regulator o-rings (that didn't look as bad as the sleeve o-rings) and carefully re-installed everything. I pumped it up to 50 bar by hand just to check for initial leaks. After that I put it on the big compressor and pumped it up to 200 bar. I couldn't hear the leak with the compressor running but once it stopped it was obvious that it was leaking fast from the vent hole. I dry-fired it to see if that would help but I'm not sure what the pressure was at when I did that. It didn't seem to help. It's holding at something over 50 bar now but it was holding about that pressure before the new sleeve o-rings too.
I have a torque screwdriver for low torque applications so I try to use it when there's a spec available. The barrel set screws seemed pretty firmly in place when I removed them. I'm guessing they only need 20-30 in-lbs.
I plan to follow the FX video from Earnest to fully rebuild the regulator: I don't have a tester but it sounds like it will be close enough if I measure carefully.
I have a torque screwdriver for low torque applications so I try to use it when there's a spec available. The barrel set screws seemed pretty firmly in place when I removed them. I'm guessing they only need 20-30 in-lbs.
I plan to follow the FX video from Earnest to fully rebuild the regulator:
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O rings that have been subjected to high air pressures will take a shape all their own to create a seal. This means stretching. If those reg o rings have been in use for longer than a week then switch them out for new. O rings are so cheap, the thought of chancing that they’ll reseal just cause they look good shouldn’t even be a thought pattern as far as I’m concerned.
In the end, when the gun is all put back together and leak free, you’ll be glad you threw in brand new half a cent o rings.
And please, do not lube aluminum threads. That streamline is exactly like the wildcat tube guns. The end caps seal with their o rings. If you apply silicone grease or oil on the threaded parts they will sieze up on you. There’s a reason when you first took it apart you never saw any lubes on any mating threads from the factory.
I’ll end this with a tip- if even after installing new o rings your vent hole still leaks(and the o rings inside the reg have also been changed), that means your air tube is overly saturated with lube, which will cause the o rings on the outside of the reg to slip out of their grooves when presdurizex(remember I said they will take a shape all their own).
Remove the reg, end caps, and clean the air tube with acetone. Then take some 2000 grit wet/dry sandpaper and lightly scuff them inside of tube where the regulator nests in inside the tube. Rev lean with acetone.
Only grease the reg o rings and push the reg in place. After the gun is all put together and pressurized, the new o rings will bite better against the air tube sides. Everytime I’ve done this it was a guarantee to not leak afterwards.
And don’t lube threaded parts!! You can’t use petroleum based products in the high pressure air areas, so one would think just use silicone but that is not a good idea, trust me and others in the know will agree.
In the end, when the gun is all put back together and leak free, you’ll be glad you threw in brand new half a cent o rings.
And please, do not lube aluminum threads. That streamline is exactly like the wildcat tube guns. The end caps seal with their o rings. If you apply silicone grease or oil on the threaded parts they will sieze up on you. There’s a reason when you first took it apart you never saw any lubes on any mating threads from the factory.
I’ll end this with a tip- if even after installing new o rings your vent hole still leaks(and the o rings inside the reg have also been changed), that means your air tube is overly saturated with lube, which will cause the o rings on the outside of the reg to slip out of their grooves when presdurizex(remember I said they will take a shape all their own).
Remove the reg, end caps, and clean the air tube with acetone. Then take some 2000 grit wet/dry sandpaper and lightly scuff them inside of tube where the regulator nests in inside the tube. Rev lean with acetone.
Only grease the reg o rings and push the reg in place. After the gun is all put together and pressurized, the new o rings will bite better against the air tube sides. Everytime I’ve done this it was a guarantee to not leak afterwards.
And don’t lube threaded parts!! You can’t use petroleum based products in the high pressure air areas, so one would think just use silicone but that is not a good idea, trust me and others in the know will agree.
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Now that's some pretty good advise right there.
And Yes I have done work on the StreamLines.
And Yes I have done work on the StreamLines.
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Good call on o-rings. I would have switched out at least the ones on the regulator housing but I didn’t have those in my collection. There was one inside the regulator and another I found out about recently that weren’t in the parts diagrams either so I made an order for a few. I’ll have plenty to replace o-rings anytime I want.
Interesting about the lube issues too. I had some excess silicone grease coming out of the vent hole. I thought I had a reasonable amount in there but maybe it was too much. Watching Ernest’s video, he hardly puts any on the o-rings. If that’s appropriate then I way overdid it and I have more than a lifetime supply of grease.
Grease on the threads must be a case-by-case issue. The threads on the Streamline have a low enough pitch and a shape that makes sense to leave un-lubed. The threads on my FWB gun cylinders (not pressurized) need just a touch of moly or they gall and stick hard. I found that out the hard way.
I just went through trying to reseal some dual-sport motorcycle forks and had to use a similar trick to add some light radial scuffing on the stanchion tubes. Those have a hard chrome plating on them and I was able to get about the right scuffing from a red Scotch-brite pad. I’ll see if I can get the cylinder sealed with new o-rings first.
I found some contact cleaner that is supposed to break down silicone grease. I was thinking of using that but it says it contains ‘petroleum distillates and isopropyl alcohol’ and I get nervous about anything potentially flammable around those high pressures. That and acetone should flash off pretty fast, but It still makes me nervous. The best thing I‘ve found to really break down silicone lubes is actually mineral spirits. I use it to clean up the silicone lube used for dirt bike mousse inserts. Again, I’m not sure I’d use it to clean out an airgun because of the compression ignition potential. It also doesn’t flash off very well. I think I’ll stick to the trusty ol’ paper towel and thorough wiping for now.
Interesting about the lube issues too. I had some excess silicone grease coming out of the vent hole. I thought I had a reasonable amount in there but maybe it was too much. Watching Ernest’s video, he hardly puts any on the o-rings. If that’s appropriate then I way overdid it and I have more than a lifetime supply of grease.
Grease on the threads must be a case-by-case issue. The threads on the Streamline have a low enough pitch and a shape that makes sense to leave un-lubed. The threads on my FWB gun cylinders (not pressurized) need just a touch of moly or they gall and stick hard. I found that out the hard way.
I just went through trying to reseal some dual-sport motorcycle forks and had to use a similar trick to add some light radial scuffing on the stanchion tubes. Those have a hard chrome plating on them and I was able to get about the right scuffing from a red Scotch-brite pad. I’ll see if I can get the cylinder sealed with new o-rings first.
I found some contact cleaner that is supposed to break down silicone grease. I was thinking of using that but it says it contains ‘petroleum distillates and isopropyl alcohol’ and I get nervous about anything potentially flammable around those high pressures. That and acetone should flash off pretty fast, but It still makes me nervous. The best thing I‘ve found to really break down silicone lubes is actually mineral spirits. I use it to clean up the silicone lube used for dirt bike mousse inserts. Again, I’m not sure I’d use it to clean out an airgun because of the compression ignition potential. It also doesn’t flash off very well. I think I’ll stick to the trusty ol’ paper towel and thorough wiping for now.
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Maybe Dawn dishwashing soap might break down Silicon grease? Don’t know. Windex might be another option.
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It has been a little while! I was waiting on o-rings and then as soon as they came I went on a short motorcycle trip. I just replaced all of the o-rings in the regulator, on the regulator housing and on the sleeve and... it's still leaking! Now instead of going down to about 50 bar and holding it just leaks everything out about as fast as it can from that little vent hole. I can't imagine where I went wrong. That regulator is a tough little thing to get apart. The threads had some kind of white thread lock compound on them. The old o-ring on the seat of the regulator was like hard, brittle plastic so who knows how long it was in there. I used a synthetic pick to remove the o-rings so I'm sure I didn't gouge anything. The only thing I can imagine is maybe the smallest o-ring in the regulator could have been torn while it was being installed. It takes quite a bit of stretching to get that one in place.
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Fx USA has a service center with a relatively quick turn around. You may just look into sending the whole gun to be re sealed then you will be set for years to come
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I thought about that. It would be interesting to know what they would charge to re-seal it. The other option might be to switch to a Huma regulator.
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Pretty interesting. I have had the exact opposite experience with lube on threads. Every gun I have I’ve put silicone grease on the threads. I’ve never had one gawl and stick tight. Thought that was just what you’re supposed to do lol. Same experience with tube regulators. I add grease to the outer o rings. They’ve almost always seal on the first try. Guess that just goes to show, everybody has their own method. Guess it’s only wrong if it doesn’t work.
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Last time I talked with FX they wanted $125 for reseal on Streamline. Not sure about shipping. After looking at the original FX and Huma side by side I went Huma.
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I see that there is a high pressure variant and a low pressure variant. Which is the one to get? Or why would I want one over the other? I'm guessing my rifle is from 2017 based on the pressure tube date of 2017 and the serial number starting with 17. I thought it had an AMP regulator though, which would make it 2019 or newer.
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I called Utah Air and ordered one from them. $89. The model they sent was like a “universal” or something like that. Can’t remember exactly but I had to modify the “plenum” they shipped. It was too long and had to cut it so the vent hole(s) would match up. Adjusting is really easy. I don’t have a chronograph and just mess around with pressure and hammer spring tension and she shoots fine. It never shot great with the FX reg.
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