Time machine won't go back past Yosemite install

Time Machine in Yosemite must completely index all of your old backups....very slowly......before it will operate again correctly.

That process will take a long time. It took about 10 hours for Time Machine to complete the process on my Mac, and I only had about 100 GB of data on my Mac and I was connected using Ethernet.

Leave things alone for a day or two, and then try to access your backups again. Post back on your progress again at that time.

Another potential issue that you are facing is that if you made a "clean" install of Yosemite, Time Machine sees your Mac as having a new hard drive, so it may not know to "add" the old backups to the new Yosemite backup. In other words, Time Machine may think that you have a new Mac.

There may be a way around that.....but it is still best to allow some time to see if things will straightnen out on their own.

If you are certain that Time Machine is adding new backups to your old backups, you will know when the indexing is complete when you can click on a date of an old backup and "see" it.

When you open Time Machine, look at the red "bars" on the far right of the screen. Scroll up and down.

If you can access a backup, the bar will be bright red. If the backup is not available yet, the bar is a darker or faded red, and clicking on it will not do anything.

Leave your Mac connected to the Time Capsule.....preferably a wired connection for the next day or two. You do not have to have Time Machine open, it is running in the background.......very slowly.

As Bob, post above, suggested: "Time Machine sees your Mac as having a new hard drive, so it may not know to "add" the old backups to the new Yosemite backup. In other words, Time Machine may think that you have a new Mac.

There may be a way around that..."

I HAD THE SAME PROBLEM.

1. ALERT MESSAGE: Is all your data from your Time Machine on your MBP retina? If so, proceed; if not, get that done. If you can't get that done I think you have to do a Clean Install of Yosemite AGAIN. And this time, when doing the first run of Yosemite on your machine be sure to click the box to MIGRATE all your data to your MBP.

2. IF ALL YOUR DATA IS ON MBP, you do have to re-establish the link from your Time Capsule to your mac. You have to, first, erase all the data from your Time Machine. Use Airport Utility to do this. (click on the Time Machine icon, go to Data tab, erase disk).

3. Then, using Time Machine preferences, you start anew like when you first set it up. Choose your newly erased Time Capsule disk, select it as your Time Machine backup.

4. When your link is re-establidshed. Back up all your data from your MBP retina to your Time Machine.

5. Then you're all set up and good to go, again.

If your Mac has been connected to the Time Capsule for the last day or so.........what happens........if you right-click on the Time Machine "clock" icon on the dock, then select Browse Other Time Machine Disks?

If your old backups were on a different "disk" (Actually a different location on the same Time Capsule disk.....Apple does not make "Browse" very clear), then you would see a normal Time Machine window with your "old" backups there.

If you don't, then it looks like Time Machine is adding the Yosemite backups to the same "disk" that your old backups were using. So, hopefully soon you will be able to see all your backups.

Please update on your progress later today or tomorrow, as far as being able to access the old backups.

Time Machine will automatically attempt to delete the oldest backups when it needs room for new backups.

This will usually work........IF......you are making small incremental backups.

BUT......if you try to back up a new large file when the drive is full......Time Machine will probably not be able to delete enough data to make room for the new backup.

That is when you have to go back into Time Machine and start to manually delete old backups, and that will take a long time, and not create much new space. Better to add another drive or Time Capsule when things start to get tight and start backups on the new drive.