Velocity adjusts until leak out of back of valve on classic RT

[Tao]

Hello everyone!

I have to admit that I completely forget how to diagnose this problem and have no idea where to find the diagnostic info again. Well I have two VHS copies of the RT video by TK himself, but alas no player to play them!


Essentially my classic RT has to be adjusted so far in that it starts leaking out the valve. I replaced the bolt spring, so that should be fine, and did lube it through the ASA. What part do I need to replace, or is this where I need to replace to "non user serviceable" safety assembly?

Thanks.

[nak81783]

Level 7 or Level 10 bolt? If the latter, you may need a newer reg piston assembly. Contact AGD or Tunaman at the links at the top of the forum.

[Tao]

Level 7 or Level 10 bolt? If the latter, you may need a newer reg piston assembly. Contact AGD or Tunaman at the links at the top of the forum.

Level 10 bolt. For what its worth it worked fine for years with the level 10.

[going_home]

[nak81783]

You mentioned you replaced the bolt spring. That might be what required the extra pressure, and put you over what the safety reg piston assy could handle. Regardless, it's best to have the newer reg piston assy when using a Level 10. If you're in a bind, put the old spring or a gold spring in to see if that allows lower pressure that won't make it leak. This will diminish antichop properties but allow you to play until you can get the new part.

[blackdeath1k]

My wifes rt pro had a L10 in it for years as well. Finally the piston gave out. When running stuff on the breaking point it may last year's. It may last minutes. Get the new piston and you should be fine.

[athomas]

If you never replaced the regulator piston assembly with a newer higher pressure version when you installed the level 10, then it probably needs to be replaced.
If the leaking out the back stops or gets reduced when you turn down the velocity, then you will know for sure that the regulator piston assembly is the problem. The leak could also be a leak around the oring surrounding the regulator piston assembly.

If it is shooting hot all the time when it is leaking, then it is probably the regulator seat oring.

Since you mentioned that it starts leaking when you adjust the velocity adjuster all the way in, then it probably isn't the regulator seat oring. The requirement to turn the velocity too far in to make it shoot is a symptom of bolt stick caused by a level 10 carrier size that is too tight. Or possibly because you are using a bolt spring that is too stiff. If you have changed level 10 powertube orings, then I would suggest adjusting the carrier size to reduce the tension on that oring. Use the largest carrier size that doesn't produce a leak. If you have installed a long silver bolt spring, then you should try one of the gold springs to see if that helps as well, at least for troubleshooing.

[Tao]

Sorry. I meant that I replaced the bolt spring thinking the old one was binding. Both with the old one and the new spring I have the same problem. This marker ran find with the level 10, but gradually it seems it needed more and more velocity adjustment over time until now it is in fairly far and leaks out the back.


just to be clear for everyone:

I have always used gold bolt springs for my level 10s. The anti chop capabilities with the standard bolt spring have always been enough for me.

[Tao]

Thanks. I didn't think of the level 10 carrier. However the level 10 was working fine (years ago now) so I might leave it or replace the carrier O ring. I will try a new reg piston assembly first before messing with the level 10 setup. Last thing I want to do is go through the finicky level 10 tuning if something else is the problem.

[athomas]

The level 10 oring could have hardened if it has sat for quite a while. That would cause sticking issues. It wouldn't explain the gradual need for an increase in velocity adjustment. That issue seems like a spring pack that is getting weak. The spring packs don't usually do that unless they experience a lot of flexing which would only be achieved by a lot of shooting. It could happen though. A carrier oring that was getting stiff might cause issues requiring an increase in velocity. Usually you get bolt stick if the carrier oring starts to get tight. However, if you are running a gold spring and have a fairly efficient barrel setup, you might have had enough pressure/force differential to hide most of that bolt stick.

I never found the level 10 tuning to be finicky. It generally just works once you use the carrier size smaller than the one that leaks. As long as you do your tuning without any shims installed, you shouldn't have any problems. If you do replace the carrier oring, you will need to tune it. Remember, its the oring tension you are adjusting by changing carrier sizes.

These are just a few things to think about. I think you are on the right track and do need to change the regulator piston assembly anyway, so it is wise to wait until that is done before you make any other big adjustment.