Important. Remember that Fix-a-Flat is designed to get you to a safe place only and should never be considered a permanent tire repair. ... The extra gunk inside your tire can throw it completely off balance.

Can Fix-a-Flat unbalance a tire?

And did they take the fix a flat out of it ... if they didn't then you have a huge amount of fix a flat rolling around inside of your tire. It usually stays in liquid form and just rolls as the tire rolls. but it will definately make your tire unbalanced.

Do you have to balance a tire after getting a patch?

If you add a patch to a tire, that is off center weight. If you do not balance the tire the off center weight might make it shake at certain speeds. You should definitely get that wheel balanced after it is patched. Depending on the patch material used on the tire to patch it, it may require a re-balance.