Getting my thrusters to stop using upper-stage RCS fuel tanks first?

[Nurb]

I've encountered this once or twice and now it's got me nuts. I have my landing craft with it's own RCS tanks on a higher stage, and my main tanks for orientation in space at the lowest stage, but when I activate RCS thrusters, it uses the smaller tanks on my higher stage lander first THEN go to my main tanks, leaving me without thrusters when I arrive. I checked the placement of tanks and such on the stages and they seem to be in the right spot... am I missing something?

[sal_vager]

It should use the bottom tank first, but it can get confused if the upper tank was replaced at some point, or added as an after-thought after the bottom tank.

Try removing the big RCS tank and chucking it back in the parts list, then add a new large RCS tank, that should change the build order so that the bottom tank is used first.

[Nurb]

It should use the bottom tank first, but it can get confused if the upper tank was replaced at some point, or added as an after-thought after the bottom tank.

Try removing the big RCS tank and chucking it back in the parts list, then add a new large RCS tank, that should change the build order so that the bottom tank is used first.

I loaded the craft and added the rocket parts to it. So I definately added the main rcs tanks last. I tried deleting and replacing the lower ones and tried saving it as a seperate craft and reloading it in the VAB but no-go

[sal_vager]

Weird, plus that has exhausted my knowledge on this topic, not seen this bug in ages to be honest, what happens if you put small RCS tanks at the bottom (as a test) or replace the top tank?

[phoenix_ca]

Try just pulling off the upper one (drop it somewhere where it isn't attached), then put it back.

[vexx32]

If that doesn't work, you want to pull of and then replace each and every RCS tank on your craft, one at a time, from top to bottom.

[Person012345]

Do fuel lines work on RCS tanks? If so you could connect the bottom ones to the top ones.

[Hremsfeld]

I'm honestly not sure if it's what you mean by your RCS being staged right, but put the tanks you want to use first on a lower stage than the ones you want to save. For example, if you've got a three stage rocket, put the tanks you want to use first on stage 2, and the ones you want to save on stage 1 or 0. Or, put the ones you want to use first on stage 1, and the others on 0.

[4 IN 1]

It seems that this is a sort of bug as I am also having the same problem even when building the rocket from scratch. Too early to tell, need more testing.

[phoenix_ca]

It is a bug indeed. RCS drainage can be a bit funky sometimes. In particular radial RCS tanks (added by mods) will get drained before any others if they are added early in the build; pulling them off and reattaching fixes it.

Person: Fuel lines don't work with RCS tanks.