I recorded a guitar part and since that one part only repeats throughout the project I decided to record it once then copy and paste it where I needed. The problem is, after the original recording all pasted files are much louder. I placed them on the same track as the original so I can't adjust the volumes. Should these these be placed on their own tracks or should be they behave the same and recognize the levels?

The copies should all be exactly the same volume as your original.
 
 

I think what happened is you have more then one copy at each location, Slide the clips and see if there's a copy underneath. 

Hmm... Didn't think of that. I'll give that a try and see what happens.

And with volume automation you can, of course, set the volume of each clip just as high or low as you want.
Also groove clipping and then stretching is a very handy method for what you're doing, assuming the clip is of exactly correct length (full measures usually).

Cactus has the most probable answer.  I've done that many times, or had a longer clip slip under a following one and wonder why it goes into red.
 
 

Cactus Music
I think what happened is you have more then one copy at each location, Slide the clips and see if there's a copy underneath. 

 
There was only one copy, but I deleted each one and recopied them. Seems fine now, but it was a lot louder. Kind of strange.

Kalle Rantaaho
And with volume automation you can, of course, set the volume of each clip just as high or low as you want.
Also groove clipping and then stretching is a very handy method for what you're doing, assuming the clip is of exactly correct length (full measures usually).

Yeah, they are all exactly the same. It only repeats twice and isn't a complicated piece really. Just something I am experimenting with to play around with the new version.
 
How do you groove clip and stretch it and what is the stretching for?

If that's the case, there should be multiple lanes in the track since SONAR isn't supposed to allow same-lane clip overlaps.

Bflat5

Cactus Music
I think what happened is you have more then one copy at each location, Slide the clips and see if there's a copy underneath. 

 
There was only one copy, but I deleted each one and recopied them. Seems fine now, but it was a lot louder. Kind of strange.

Kalle Rantaaho
And with volume automation you can, of course, set the volume of each clip just as high or low as you want.
Also groove clipping and then stretching is a very handy method for what you're doing, assuming the clip is of exactly correct length (full measures usually).

Yeah, they are all exactly the same. It only repeats twice and isn't a complicated piece really. Just something I am experimenting with to play around with the new version.
 
How do you groove clip and stretch it and what is the stretching for?

You turn a regular clip into a groove clip by selecting hit & hitting ctrl + L
You'll know it's a Groove Clip when the corners appear rounded
You can then simply drag the right hand edge of it as though you're slip editing but the clip will now repeat for as long as you want
But the caveat is what was stated above - the original clip MUST be a whole number of measures long or you will get timing errors

Thanks for the tip on that. Pretty cool.
 
And thanks for all of the replies and info as well. :)